From fe33a82a072bfe657f509bd9b7d756f10a92817f Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 01:15:49 +0000 Subject: feat: Initial check-in of type system sketch --- yants.md | 16 ++++++++++++ yants.nix | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 104 insertions(+) create mode 100644 yants.md create mode 100644 yants.nix diff --git a/yants.md b/yants.md new file mode 100644 index 0000000000..dcdea0bd38 --- /dev/null +++ b/yants.md @@ -0,0 +1,16 @@ +yants +===== + +This is a tiny type-checker for data in Nix, written in Nix. It doesn't have all the features I think it should have (yet), but it works and its types are composable. + +## Primitives & simple polymorphism + +![simple](https://i.imgur.com/hDQAQUK.png) + +## Structs + +![structs](https://i.imgur.com/f8jgnul.png) + +## Nested structs! + +![nested structs](https://i.imgur.com/O3RsHds.png) \ No newline at end of file diff --git a/yants.nix b/yants.nix new file mode 100644 index 0000000000..feb3b8fd34 --- /dev/null +++ b/yants.nix @@ -0,0 +1,88 @@ +# Provides a "type-system" for Nix that provides various primitive & +# polymorphic types as well as the ability to define & check records. +# +# All types (should) compose as expected. +# +# TODO: +# - error messages for type-checks of map/list elements are bad +# - enums? + +{ toPretty ? ((import {}).lib.generators.toPretty) }: + +# Checks are simply functions of the type `a -> bool` which check +# whether `a` conforms to the specification. +with builtins; let + # Internal utilities: + typeError = type: val: + throw "Expected type '${type}', but value '${toPretty {} val}' is of type '${typeOf val}'"; + + typedef = name: check: { + inherit name check; + __functor = self: value: + if check value then value + else typeError name value; + }; + + poly = n: c: { "${n}" = t: typedef "${n}<${t.name}>" (c t); }; + + poly2 = n: c: { + "${n}" = t1: t2: typedef "${n}<${t1.name},${t2.name}>" (c t1 t2); + }; + + typeSet = foldl' (s: t: s // (if t ? "name" then { "${t.name}" = t; } else t)) {}; + + # Struct checker implementation + # + # Checks performed: + # 1. All existing fields match their types + # 2. No non-optional fields are missing. + # 3. No unexpected fields are in the struct. + # + # Anonymous structs are supported (e.g. for nesting) by omitting the + # name. + checkField = def: value: current: field: + let + fieldVal = if hasAttr field value then value."${field}" else null; + type = def."${field}"; + checked = type.check fieldVal; + in if checked then (current && true) + else (throw "Field ${field} is of type ${typeOf fieldVal}, but expected ${type.name}"); + + checkExtraneous = name: def: present: + if (length present) == 0 then true + else if (hasAttr (head present) def) + then checkExtraneous name def (tail present) + else (throw "Found unexpected field '${head present}' in struct '${name}'"); + + struct' = name: def: { + inherit name def; + check = value: + let + fieldMatch = foldl' (checkField def value) true (attrNames def); + noExtras = checkExtraneous name def (attrNames value); + in (isAttrs value && fieldMatch && noExtras); + + __functor = self: value: if self.check value + then value + else (throw "Expected '${self.name}'-struct, but ${toPretty value} is of type ${typeOf value}"); + }; + + struct = arg: + if isString arg then (struct' arg) + else (struct' "anonymous" arg); +in (typeSet [ + # Primitive types + (typedef "any" (_: true)) + (typedef "int" isInt) + (typedef "bool" isBool) + (typedef "float" isFloat) + (typedef "string" isString) + + # Polymorphic types + (poly "option" (t: v: (isNull v) || t.check v)) + (poly "list" (t: v: isList v && (foldl' (s: e: s && (t.check e)) true v))) + (poly "attrs" (t: v: + isAttrs v && (foldl' (s: e: s && (t.check e)) true (attrValues v)) + )) + (poly2 "either" (t1: t2: v: t1.check v || t2.check v)) +]) // { inherit struct; } -- cgit 1.4.1 From 040b719570aea8fc98a6438002c693df6c92f54d Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 12:47:22 +0100 Subject: feat: Support better error messages for list/attrs element checks --- yants.nix | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/yants.nix b/yants.nix index feb3b8fd34..03e5114033 100644 --- a/yants.nix +++ b/yants.nix @@ -4,17 +4,16 @@ # All types (should) compose as expected. # # TODO: -# - error messages for type-checks of map/list elements are bad # - enums? -{ toPretty ? ((import {}).lib.generators.toPretty) }: +{ toPretty ? ((import {}).lib.generators.toPretty {}) }: # Checks are simply functions of the type `a -> bool` which check # whether `a` conforms to the specification. with builtins; let # Internal utilities: typeError = type: val: - throw "Expected type '${type}', but value '${toPretty {} val}' is of type '${typeOf val}'"; + throw "Expected type '${type}', but value '${toPretty val}' is of type '${typeOf val}'"; typedef = name: check: { inherit name check; @@ -80,9 +79,18 @@ in (typeSet [ # Polymorphic types (poly "option" (t: v: (isNull v) || t.check v)) - (poly "list" (t: v: isList v && (foldl' (s: e: s && (t.check e)) true v))) + + (poly "list" (t: v: isList v && (foldl' (s: e: s && ( + if t.check e then true + else throw "Expected list element of type '${t.name}', but '${toPretty e}' is of type '${typeOf e}'" + )) true v))) + (poly "attrs" (t: v: - isAttrs v && (foldl' (s: e: s && (t.check e)) true (attrValues v)) + isAttrs v && (foldl' (s: e: s && ( + if t.check e then true + else throw "Expected attribute set element of type '${t.name}', but '${toPretty e}' is of type '${typeOf e}'" + )) true (attrValues v)) )) + (poly2 "either" (t1: t2: v: t1.check v || t2.check v)) ]) // { inherit struct; } -- cgit 1.4.1 From 199254ba7ae008e820c8cb960b4d6edec6cdc50a Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 12:52:54 +0100 Subject: chore: Move screenshots into the gist --- yants.md | 6 +++--- z-nested-structs.png | Bin 0 -> 70264 bytes z-simple.png | Bin 0 -> 43010 bytes z-structs.png | Bin 0 -> 67989 bytes 4 files changed, 3 insertions(+), 3 deletions(-) create mode 100644 z-nested-structs.png create mode 100644 z-simple.png create mode 100644 z-structs.png diff --git a/yants.md b/yants.md index dcdea0bd38..fe2affd5e8 100644 --- a/yants.md +++ b/yants.md @@ -5,12 +5,12 @@ This is a tiny type-checker for data in Nix, written in Nix. It doesn't have all ## Primitives & simple polymorphism -![simple](https://i.imgur.com/hDQAQUK.png) +![simple](z-simple.png) ## Structs -![structs](https://i.imgur.com/f8jgnul.png) +![structs](z-structs.png) ## Nested structs! -![nested structs](https://i.imgur.com/O3RsHds.png) \ No newline at end of file +![nested structs](z-nested-structs.png) diff --git a/z-nested-structs.png b/z-nested-structs.png new file mode 100644 index 0000000000..6b03ed65ce Binary files /dev/null and b/z-nested-structs.png differ diff --git a/z-simple.png b/z-simple.png new file mode 100644 index 0000000000..05a302cc6b Binary files /dev/null and b/z-simple.png differ diff --git a/z-structs.png b/z-structs.png new file mode 100644 index 0000000000..f46e15ade5 Binary files /dev/null and b/z-structs.png differ -- cgit 1.4.1 From cb0d07fa30c40beaef815614fee949f496edc514 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 12:54:45 +0100 Subject: docs: Fix image links (relative is not supported in gists) --- yants.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/yants.md b/yants.md index fe2affd5e8..a6132a22e8 100644 --- a/yants.md +++ b/yants.md @@ -5,12 +5,12 @@ This is a tiny type-checker for data in Nix, written in Nix. It doesn't have all ## Primitives & simple polymorphism -![simple](z-simple.png) +![simple](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7b1fa0a511ae40f0831b369df4b97103441c7e5/z-simple.png) ## Structs -![structs](z-structs.png) +![structs](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7b1fa0a511ae40f0831b369df4b97103441c7e5/z-structs.png) ## Nested structs! -![nested structs](z-nested-structs.png) +![nested structs](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7b1fa0a511ae40f0831b369df4b97103441c7e5/z-nested-structs.png) -- cgit 1.4.1 From 103e0b4d2531569903c362e9e592b297248057ca Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 13:05:29 +0100 Subject: feat: Add derivation type --- yants.nix | 3 +++ 1 file changed, 3 insertions(+) diff --git a/yants.nix b/yants.nix index 03e5114033..c5fff0ea7d 100644 --- a/yants.nix +++ b/yants.nix @@ -28,6 +28,8 @@ with builtins; let "${n}" = t1: t2: typedef "${n}<${t1.name},${t2.name}>" (c t1 t2); }; + ofType = t: x: isAttrs x && x ? "type" && x.type == t; + typeSet = foldl' (s: t: s // (if t ? "name" then { "${t.name}" = t; } else t)) {}; # Struct checker implementation @@ -76,6 +78,7 @@ in (typeSet [ (typedef "bool" isBool) (typedef "float" isFloat) (typedef "string" isString) + (typedef "derivation" (ofType "derivation")) # Polymorphic types (poly "option" (t: v: (isNull v) || t.check v)) -- cgit 1.4.1 From 76f9b1638cef4f77fea94e77c1440bf85eaf52d3 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 13:13:31 +0100 Subject: feat: Add function type It's not currently possible to check arguments for curried functions, but there might be something on the horizon for attribute set functions. --- yants.nix | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/yants.nix b/yants.nix index c5fff0ea7d..e7b758f4b9 100644 --- a/yants.nix +++ b/yants.nix @@ -78,8 +78,9 @@ in (typeSet [ (typedef "bool" isBool) (typedef "float" isFloat) (typedef "string" isString) - (typedef "derivation" (ofType "derivation")) - + (typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation")) + (typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" + && isFunction x.__functor))) # Polymorphic types (poly "option" (t: v: (isNull v) || t.check v)) -- cgit 1.4.1 From 2acdbb500926e3a61f85269858efbda29d64d539 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 13:14:52 +0100 Subject: refactor: Drop back to below 100 lines :) --- yants.nix | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/yants.nix b/yants.nix index e7b758f4b9..8da43f6385 100644 --- a/yants.nix +++ b/yants.nix @@ -3,13 +3,10 @@ # # All types (should) compose as expected. # -# TODO: -# - enums? +# TODO(tazjin): enums? { toPretty ? ((import {}).lib.generators.toPretty {}) }: -# Checks are simply functions of the type `a -> bool` which check -# whether `a` conforms to the specification. with builtins; let # Internal utilities: typeError = type: val: @@ -32,9 +29,8 @@ with builtins; let typeSet = foldl' (s: t: s // (if t ? "name" then { "${t.name}" = t; } else t)) {}; - # Struct checker implementation + # Struct checks performed: # - # Checks performed: # 1. All existing fields match their types # 2. No non-optional fields are missing. # 3. No unexpected fields are in the struct. -- cgit 1.4.1 From 2e576e10ab2d75d586bdf82f1fa0369b0352ef3d Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 13:24:05 +0100 Subject: refactor: Gain back a few more lines --- yants.nix | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/yants.nix b/yants.nix index 8da43f6385..f803740660 100644 --- a/yants.nix +++ b/yants.nix @@ -25,23 +25,18 @@ with builtins; let "${n}" = t1: t2: typedef "${n}<${t1.name},${t2.name}>" (c t1 t2); }; - ofType = t: x: isAttrs x && x ? "type" && x.type == t; - typeSet = foldl' (s: t: s // (if t ? "name" then { "${t.name}" = t; } else t)) {}; - # Struct checks performed: - # - # 1. All existing fields match their types - # 2. No non-optional fields are missing. - # 3. No unexpected fields are in the struct. + # Struct implementation. Checks that all fields match their declared + # types, no optional fields are missing and no unexpected fields + # occur in the struct. # # Anonymous structs are supported (e.g. for nesting) by omitting the # name. checkField = def: value: current: field: - let - fieldVal = if hasAttr field value then value."${field}" else null; - type = def."${field}"; - checked = type.check fieldVal; + let fieldVal = if hasAttr field value then value."${field}" else null; + type = def."${field}"; + checked = type.check fieldVal; in if checked then (current && true) else (throw "Field ${field} is of type ${typeOf fieldVal}, but expected ${type.name}"); @@ -64,9 +59,8 @@ with builtins; let else (throw "Expected '${self.name}'-struct, but ${toPretty value} is of type ${typeOf value}"); }; - struct = arg: - if isString arg then (struct' arg) - else (struct' "anonymous" arg); + struct = arg: if isString arg then (struct' arg) + else (struct' "anonymous" arg); in (typeSet [ # Primitive types (typedef "any" (_: true)) -- cgit 1.4.1 From 661e09daace3e611726d83f23e5ac02b2b561d5d Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 13:55:06 +0100 Subject: feat: Add enum support --- yants.nix | 37 ++++++++++++++++++++++--------------- z-enums.png | Bin 0 -> 41305 bytes 2 files changed, 22 insertions(+), 15 deletions(-) create mode 100644 z-enums.png diff --git a/yants.nix b/yants.nix index f803740660..3dfebfcf1f 100644 --- a/yants.nix +++ b/yants.nix @@ -2,13 +2,10 @@ # polymorphic types as well as the ability to define & check records. # # All types (should) compose as expected. -# -# TODO(tazjin): enums? { toPretty ? ((import {}).lib.generators.toPretty {}) }: with builtins; let - # Internal utilities: typeError = type: val: throw "Expected type '${type}', but value '${toPretty val}' is of type '${typeOf val}'"; @@ -49,18 +46,30 @@ with builtins; let struct' = name: def: { inherit name def; check = value: - let - fieldMatch = foldl' (checkField def value) true (attrNames def); - noExtras = checkExtraneous name def (attrNames value); + let fieldMatch = foldl' (checkField def value) true (attrNames def); + noExtras = checkExtraneous name def (attrNames value); in (isAttrs value && fieldMatch && noExtras); - __functor = self: value: if self.check value - then value + __functor = self: value: if self.check value then value else (throw "Expected '${self.name}'-struct, but ${toPretty value} is of type ${typeOf value}"); }; struct = arg: if isString arg then (struct' arg) else (struct' "anonymous" arg); + + enum = name: values: rec { + inherit name values; + check = (x: elem x values); + __functor = self: x: if self.check x then x + else (throw "'${x}' is not a member of enum '${self.name}'"); + match = x: actions: let + actionKeys = map (__functor { inherit name check; }) (attrNames actions); + missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] values; + in if (length missing) > 0 + then throw "Missing match action for members: ${toPretty missing}" + else actions."${__functor { inherit name check; } x}"; + }; + in (typeSet [ # Primitive types (typedef "any" (_: true)) @@ -79,12 +88,10 @@ in (typeSet [ else throw "Expected list element of type '${t.name}', but '${toPretty e}' is of type '${typeOf e}'" )) true v))) - (poly "attrs" (t: v: - isAttrs v && (foldl' (s: e: s && ( - if t.check e then true - else throw "Expected attribute set element of type '${t.name}', but '${toPretty e}' is of type '${typeOf e}'" - )) true (attrValues v)) - )) + (poly "attrs" (t: v: isAttrs v && (foldl' (s: e: s && ( + if t.check e then true + else throw "Expected attribute set element of type '${t.name}', but '${toPretty e}' is of type '${typeOf e}'" + )) true (attrValues v)))) (poly2 "either" (t1: t2: v: t1.check v || t2.check v)) -]) // { inherit struct; } +]) // { inherit struct enum; } diff --git a/z-enums.png b/z-enums.png new file mode 100644 index 0000000000..71673e7ab6 Binary files /dev/null and b/z-enums.png differ -- cgit 1.4.1 From 4ebc069a3f4b23aa9409be7b0363393556bdbdd4 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 13:56:08 +0100 Subject: docs: Add enum screenshot to README --- yants.md | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/yants.md b/yants.md index a6132a22e8..83a615a378 100644 --- a/yants.md +++ b/yants.md @@ -1,7 +1,9 @@ yants ===== -This is a tiny type-checker for data in Nix, written in Nix. It doesn't have all the features I think it should have (yet), but it works and its types are composable. +This is a tiny type-checker for data in Nix, written in Nix. It doesn't have all +the features I think it should have (yet), but it works and its types are +composable. ## Primitives & simple polymorphism @@ -14,3 +16,7 @@ This is a tiny type-checker for data in Nix, written in Nix. It doesn't have all ## Nested structs! ![nested structs](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7b1fa0a511ae40f0831b369df4b97103441c7e5/z-nested-structs.png) + +## Enums! + +![enums](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/b435b5996a176a9e824c42da4713a1d30f261338/z-enums.png) -- cgit 1.4.1 From ca0cf11ca9fe1fd80c8edeb71d2a66016d9798d5 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 15:07:36 +0100 Subject: feat: Improved error message for missing struct fields --- yants.nix | 3 ++- z-structs.png | Bin 67989 -> 69499 bytes 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/yants.nix b/yants.nix index 3dfebfcf1f..a00d084392 100644 --- a/yants.nix +++ b/yants.nix @@ -35,7 +35,8 @@ with builtins; let type = def."${field}"; checked = type.check fieldVal; in if checked then (current && true) - else (throw "Field ${field} is of type ${typeOf fieldVal}, but expected ${type.name}"); + else if isNull fieldVal then (throw "Missing required ${type.name} field '${field}'") + else (throw "Field ${field} is of type ${typeOf fieldVal}, but expected ${type.name}"); checkExtraneous = name: def: present: if (length present) == 0 then true diff --git a/z-structs.png b/z-structs.png index f46e15ade5..fcbcf6415f 100644 Binary files a/z-structs.png and b/z-structs.png differ -- cgit 1.4.1 From bc130254bc5666e135382ce9f58e8ea96f5ba47e Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 15:08:40 +0100 Subject: docs: Update struct screenshot in README --- yants.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/yants.md b/yants.md index 83a615a378..6db2068255 100644 --- a/yants.md +++ b/yants.md @@ -11,7 +11,7 @@ composable. ## Structs -![structs](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7b1fa0a511ae40f0831b369df4b97103441c7e5/z-structs.png) +![structs](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7a7cff3639115538a5085561bedf11cb36d04e7/z-structs.png) ## Nested structs! -- cgit 1.4.1 From 08116dbf51a771e148b11ed3486632a6ac11bca7 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 22:14:20 +0100 Subject: chore: Add Google's copyright header --- yants.nix | 3 +++ 1 file changed, 3 insertions(+) diff --git a/yants.nix b/yants.nix index a00d084392..a24792f8a5 100644 --- a/yants.nix +++ b/yants.nix @@ -1,3 +1,6 @@ +# Copyright 2019 Google LLC +# SPDX-License-Identifier: Apache-2.0 +# # Provides a "type-system" for Nix that provides various primitive & # polymorphic types as well as the ability to define & check records. # -- cgit 1.4.1 From 1da22249bd65ffeb6de1382d0a39da9240e63091 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 22:20:00 +0100 Subject: test: Add some simple tests for type-checks Does not currently test check failures, which makes it sort of not as useful as you'd think. --- yants-tests.nix | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 yants-tests.nix diff --git a/yants-tests.nix b/yants-tests.nix new file mode 100644 index 0000000000..8847758ced --- /dev/null +++ b/yants-tests.nix @@ -0,0 +1,48 @@ +with (import ./yants.nix {}); +with builtins; + +# Note: Derivations are not included in the tests below as they cause +# issues with deepSeq. + +deepSeq rec { + # Test that all primitive types match + primitives = [ + (int 15) + (bool false) + (float 13.37) + (string "Hello!") + (function (x: x * 2)) + ]; + + # Test that polymorphic types work as intended + poly = [ + (option int null) + (list string [ "foo" "bar" ]) + (either int float 42) + ]; + + # Test that structures work as planned. + person = struct "person" { + name = string; + age = int; + + contact = option (struct { + email = string; + phone = option string; + }); + }; + + testPerson = person { + name = "Brynhjulf"; + age = 42; + contact.email = "brynhjulf@yants.nix"; + }; + + # Test enum definitions & matching + colour = enum "colour" [ "red" "blue" "green" ]; + testMatch = colour.match "red" { + red = "It is in fact red!"; + blue = throw "It should not be blue!"; + green = throw "It should not be green!"; + }; +} "All tests passed!\n" -- cgit 1.4.1 From 5949663fcd843fe746f602f4a2509a11d8a94f06 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 23:32:43 +0100 Subject: feat: Implement support for typing functions The defun helper takes a type signature and a function and makes a typed version. Because we can. --- yants-tests.nix | 6 ++++++ yants.nix | 15 ++++++++++++++- z-functions.png | Bin 0 -> 32907 bytes 3 files changed, 20 insertions(+), 1 deletion(-) create mode 100644 z-functions.png diff --git a/yants-tests.nix b/yants-tests.nix index 8847758ced..e089aab467 100644 --- a/yants-tests.nix +++ b/yants-tests.nix @@ -45,4 +45,10 @@ deepSeq rec { blue = throw "It should not be blue!"; green = throw "It should not be green!"; }; + + # Test curried function definitions + func = defun [ string int string ] + (name: age: "${name} is ${toString age} years old"); + + testFunc = func "Brynhjulf" 42; } "All tests passed!\n" diff --git a/yants.nix b/yants.nix index a24792f8a5..51bc5fe5c4 100644 --- a/yants.nix +++ b/yants.nix @@ -74,6 +74,19 @@ with builtins; let else actions."${__functor { inherit name check; } x}"; }; + mkFunc = sig: f: { + inherit sig; + __toString = self: foldl' (s: t: "${s} -> ${t.name}") + "λ :: ${(head self.sig).name}" (tail self.sig); + __functor = _: f; + }; + defun' = sig: func: if length sig > 2 + then mkFunc sig (x: defun' (tail sig) (func ((head sig) x))) + else mkFunc sig (x: ((head (tail sig)) (func ((head sig) x)))); + + defun = sig: func: if length sig < 2 + then (throw "Signature must at least have two types (a -> b)") + else defun' sig func; in (typeSet [ # Primitive types (typedef "any" (_: true)) @@ -98,4 +111,4 @@ in (typeSet [ )) true (attrValues v)))) (poly2 "either" (t1: t2: v: t1.check v || t2.check v)) -]) // { inherit struct enum; } +]) // { inherit struct enum defun; } diff --git a/z-functions.png b/z-functions.png new file mode 100644 index 0000000000..30ed50f832 Binary files /dev/null and b/z-functions.png differ -- cgit 1.4.1 From ef4ded7b98f503b6d39c9e2fb843fb8de94279d9 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 8 Aug 2019 23:41:17 +0100 Subject: docs: Add defun to README --- yants-tests.nix | 54 ------------------------------------------------------ yants.md | 22 +++++++++++++++++++--- z-yants-tests.nix | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 73 insertions(+), 57 deletions(-) delete mode 100644 yants-tests.nix create mode 100644 z-yants-tests.nix diff --git a/yants-tests.nix b/yants-tests.nix deleted file mode 100644 index e089aab467..0000000000 --- a/yants-tests.nix +++ /dev/null @@ -1,54 +0,0 @@ -with (import ./yants.nix {}); -with builtins; - -# Note: Derivations are not included in the tests below as they cause -# issues with deepSeq. - -deepSeq rec { - # Test that all primitive types match - primitives = [ - (int 15) - (bool false) - (float 13.37) - (string "Hello!") - (function (x: x * 2)) - ]; - - # Test that polymorphic types work as intended - poly = [ - (option int null) - (list string [ "foo" "bar" ]) - (either int float 42) - ]; - - # Test that structures work as planned. - person = struct "person" { - name = string; - age = int; - - contact = option (struct { - email = string; - phone = option string; - }); - }; - - testPerson = person { - name = "Brynhjulf"; - age = 42; - contact.email = "brynhjulf@yants.nix"; - }; - - # Test enum definitions & matching - colour = enum "colour" [ "red" "blue" "green" ]; - testMatch = colour.match "red" { - red = "It is in fact red!"; - blue = throw "It should not be blue!"; - green = throw "It should not be green!"; - }; - - # Test curried function definitions - func = defun [ string int string ] - (name: age: "${name} is ${toString age} years old"); - - testFunc = func "Brynhjulf" 42; -} "All tests passed!\n" diff --git a/yants.md b/yants.md index 6db2068255..e10e120f08 100644 --- a/yants.md +++ b/yants.md @@ -1,9 +1,21 @@ yants ===== -This is a tiny type-checker for data in Nix, written in Nix. It doesn't have all -the features I think it should have (yet), but it works and its types are -composable. +This is a tiny type-checker for data in Nix, written in Nix. + +Features: + +* Checking of primitive types (`int`, `string` etc.) +* Checking polymorphic types (`option`, `list`, `either`) +* Defining & checking struct/record types +* Defining & matching enum types +* Defining function signatures (including curried functions) +* Types are composable! `option string`! `list (either int (option float))`! + +Lacking: + +* Any kind of inference (Nix's reflection ability is not strong enough) +* Convenient syntax for attribute-set function signatures ## Primitives & simple polymorphism @@ -20,3 +32,7 @@ composable. ## Enums! ![enums](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/b435b5996a176a9e824c42da4713a1d30f261338/z-enums.png) + +## Functions! + +![functions](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/ccece1eb9a1cb3b1add1ba1a1f65df3adca64a8f/z-functions.png) diff --git a/z-yants-tests.nix b/z-yants-tests.nix new file mode 100644 index 0000000000..e089aab467 --- /dev/null +++ b/z-yants-tests.nix @@ -0,0 +1,54 @@ +with (import ./yants.nix {}); +with builtins; + +# Note: Derivations are not included in the tests below as they cause +# issues with deepSeq. + +deepSeq rec { + # Test that all primitive types match + primitives = [ + (int 15) + (bool false) + (float 13.37) + (string "Hello!") + (function (x: x * 2)) + ]; + + # Test that polymorphic types work as intended + poly = [ + (option int null) + (list string [ "foo" "bar" ]) + (either int float 42) + ]; + + # Test that structures work as planned. + person = struct "person" { + name = string; + age = int; + + contact = option (struct { + email = string; + phone = option string; + }); + }; + + testPerson = person { + name = "Brynhjulf"; + age = 42; + contact.email = "brynhjulf@yants.nix"; + }; + + # Test enum definitions & matching + colour = enum "colour" [ "red" "blue" "green" ]; + testMatch = colour.match "red" { + red = "It is in fact red!"; + blue = throw "It should not be blue!"; + green = throw "It should not be green!"; + }; + + # Test curried function definitions + func = defun [ string int string ] + (name: age: "${name} is ${toString age} years old"); + + testFunc = func "Brynhjulf" 42; +} "All tests passed!\n" -- cgit 1.4.1 From f6635fec982ecf892f77dde82568689631932d85 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 24 Aug 2019 14:10:41 +0100 Subject: feat: Add rough initial version of sum types Sum types are represented as attribute sets with a single key in them. --- yants.nix | 16 +++++++++++++++- z-yants-tests.nix | 17 +++++++++++++++++ 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/yants.nix b/yants.nix index 51bc5fe5c4..26c5b317c9 100644 --- a/yants.nix +++ b/yants.nix @@ -74,6 +74,20 @@ with builtins; let else actions."${__functor { inherit name check; } x}"; }; + sum = name: values: let + isVariant = x: + let name = elemAt (attrNames x) 0; + in if hasAttr name values + then values."${name}".check x."${name}" + else false; + check = x: isAttrs x && length (attrNames x) == 1 && isVariant x; + in { + inherit name values check; + __functor = self: x: if self.check x + then x + else throw "'${toPretty x}' is not a valid variant of '${name}'"; + }; + mkFunc = sig: f: { inherit sig; __toString = self: foldl' (s: t: "${s} -> ${t.name}") @@ -111,4 +125,4 @@ in (typeSet [ )) true (attrValues v)))) (poly2 "either" (t1: t2: v: t1.check v || t2.check v)) -]) // { inherit struct enum defun; } +]) // { inherit struct enum sum defun; } diff --git a/z-yants-tests.nix b/z-yants-tests.nix index e089aab467..f468f61322 100644 --- a/z-yants-tests.nix +++ b/z-yants-tests.nix @@ -46,6 +46,23 @@ deepSeq rec { green = throw "It should not be green!"; }; + # Test sum type definitions + creature = sum "creature" { + human = struct { + name = string; + age = option int; + }; + + pet = enum "pet" [ "dog" "lizard" "cat" ]; + }; + + testSum = creature { + human = { + name = "Brynhjulf"; + age = 42; + }; + }; + # Test curried function definitions func = defun [ string int string ] (name: age: "${name} is ${toString age} years old"); -- cgit 1.4.1 From b622bcef7de3d69d3aa52b9c43c89906c75f0ae3 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 13:31:14 +0100 Subject: feat: Introduce composable type errors and type parameter checking This refactoring moves the type definitions into a recursively evaluated attribute set, which makes it possibe to refer to types in the definitions of other types. This functionality is used to type-check some of the type parameters passed in to other types. This is not yet done for all higher-order types because the evaluation semantics of Nix make it less useful for some cases. Further the definition of a type itself is now a stricter representation that works for all types except typed functions, which allows for composable error messages. --- yants.nix | 369 +++++++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 268 insertions(+), 101 deletions(-) diff --git a/yants.nix b/yants.nix index 26c5b317c9..17564b61b9 100644 --- a/yants.nix +++ b/yants.nix @@ -6,123 +6,290 @@ # # All types (should) compose as expected. -{ toPretty ? ((import {}).lib.generators.toPretty {}) }: +{ lib ? (import {}).lib }: with builtins; let - typeError = type: val: - throw "Expected type '${type}', but value '${toPretty val}' is of type '${typeOf val}'"; + prettyPrint = lib.generators.toPretty {}; - typedef = name: check: { - inherit name check; - __functor = self: value: - if check value then value - else typeError name value; - }; + # typedef' :: struct { + # name = string; + # checkType = function; (a -> result) + # checkToBool = option function; (result -> bool) + # toError = option function; (a -> result -> string) + # def = option any; + # match = option function; + # } -> type + # -> (a -> b) + # -> (b -> bool) + # -> (a -> b -> string) + # -> type + # + # This function creates an attribute set that acts as a type. + # + # It receives a type name, a function that is used to perform a + # check on an arbitrary value, a function that can translate the + # return of that check to a boolean that informs whether the value + # is type-conformant, and a function that can construct error + # messages from the check result. + # + # This function is the low-level primitive used to create types. For + # many cases the higher-level 'typedef' function is more appropriate. + typedef' = { name, checkType + , checkToBool ? (result: result.ok) + , toError ? (_: result: result.err) + , def ? null + , match ? null }: { + inherit name checkToBool toError; + + # check :: a -> bool + # + # This function is used to determine whether a given type is + # conformant. + check = value: checkToBool (checkType value); - poly = n: c: { "${n}" = t: typedef "${n}<${t.name}>" (c t); }; + # checkType :: a -> struct { ok = bool; err = option string; } + # + # This function checks whether the passed value is type conformant + # and returns an optional type error string otherwise. + inherit checkType; - poly2 = n: c: { - "${n}" = t1: t2: typedef "${n}<${t1.name},${t2.name}>" (c t1 t2); + # __functor :: a -> a + # + # This function checks whether the passed value is type conformant + # and throws an error if it is not. + # + # The name of this function is a special attribute in Nix that + # makes it possible to execute a type attribute set like a normal + # function. + __functor = self: value: + let result = self.checkType value; + in if checkToBool result then value + else throw (toError value result); }; - typeSet = foldl' (s: t: s // (if t ? "name" then { "${t.name}" = t; } else t)) {}; + typeError = type: val: + "expected type '${type}', but value '${prettyPrint val}' is of type '${typeOf val}'"; - # Struct implementation. Checks that all fields match their declared - # types, no optional fields are missing and no unexpected fields - # occur in the struct. + # typedef :: string -> (a -> bool) -> type # - # Anonymous structs are supported (e.g. for nesting) by omitting the - # name. - checkField = def: value: current: field: - let fieldVal = if hasAttr field value then value."${field}" else null; - type = def."${field}"; - checked = type.check fieldVal; - in if checked then (current && true) - else if isNull fieldVal then (throw "Missing required ${type.name} field '${field}'") - else (throw "Field ${field} is of type ${typeOf fieldVal}, but expected ${type.name}"); - - checkExtraneous = name: def: present: - if (length present) == 0 then true - else if (hasAttr (head present) def) - then checkExtraneous name def (tail present) - else (throw "Found unexpected field '${head present}' in struct '${name}'"); - - struct' = name: def: { - inherit name def; - check = value: - let fieldMatch = foldl' (checkField def value) true (attrNames def); - noExtras = checkExtraneous name def (attrNames value); - in (isAttrs value && fieldMatch && noExtras); - - __functor = self: value: if self.check value then value - else (throw "Expected '${self.name}'-struct, but ${toPretty value} is of type ${typeOf value}"); + # typedef is the simplified version of typedef' which uses a default + # error message constructor. + typedef = name: check: typedef' { + inherit name; + checkType = check; + checkToBool = r: r; + toError = value: _result: typeError name value; }; - struct = arg: if isString arg then (struct' arg) - else (struct' "anonymous" arg); - - enum = name: values: rec { - inherit name values; - check = (x: elem x values); - __functor = self: x: if self.check x then x - else (throw "'${x}' is not a member of enum '${self.name}'"); - match = x: actions: let - actionKeys = map (__functor { inherit name check; }) (attrNames actions); - missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] values; - in if (length missing) > 0 - then throw "Missing match action for members: ${toPretty missing}" - else actions."${__functor { inherit name check; } x}"; + checkEach = name: t: l: foldl' (acc: e: + let res = t.checkType e; + isT = t.checkToBool res; + in { + ok = acc.ok && isT; + err = if isT + then acc.err + else acc.err + "${prettyPrint e}: ${t.toError e res}\n"; + }) { ok = true; err = "expected type ${name}, but found:\n"; } l; +in lib.fix (self: { + # Primitive types + any = typedef "any" (_: true); + int = typedef "int" isInt; + bool = typedef "bool" isBool; + float = typedef "float" isFloat; + string = typedef "string" isString; + drv = typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation"); + function = typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" + && isFunction x.__functor)); + + # Type for types themselves. Useful when defining polymorphic types. + type = typedef "type" (x: + isAttrs x + && hasAttr "name" x && self.string.check x.name + && hasAttr "checkType" x && self.function.check x.checkType + && hasAttr "checkToBool" x && self.function.check x.checkToBool + && hasAttr "toError" x && self.function.check x.toError + ); + + # Polymorphic types + option = t: typedef' rec { + name = "option<${t.name}>"; + checkType = v: + let res = t.checkType v; + in { + ok = isNull v || (self.type t).checkToBool res; + err = "expected type ${name}, but value does not conform to '${t.name}': " + + t.toError v res; + }; }; - sum = name: values: let - isVariant = x: - let name = elemAt (attrNames x) 0; - in if hasAttr name values - then values."${name}".check x."${name}" - else false; - check = x: isAttrs x && length (attrNames x) == 1 && isVariant x; - in { - inherit name values check; - __functor = self: x: if self.check x - then x - else throw "'${toPretty x}' is not a valid variant of '${name}'"; + either = t1: t2: typedef "either<${t1.name},${t2.name}>" + (x: (self.type t1).check x || (self.type t2).check x); + + list = t: typedef' rec { + name = "list<${t.name}>"; + + checkType = v: if isList v + then checkEach name (self.type t) v + else { + ok = false; + err = typeError name v; + }; }; - mkFunc = sig: f: { - inherit sig; - __toString = self: foldl' (s: t: "${s} -> ${t.name}") - "λ :: ${(head self.sig).name}" (tail self.sig); - __functor = _: f; + attrs = t: typedef' rec { + name = "attrs<${t.name}>"; + + checkType = v: if isAttrs v + then checkEach name (self.type t) (attrValues v) + else { + ok = false; + err = typeError name v; + }; }; - defun' = sig: func: if length sig > 2 - then mkFunc sig (x: defun' (tail sig) (func ((head sig) x))) - else mkFunc sig (x: ((head (tail sig)) (func ((head sig) x)))); - - defun = sig: func: if length sig < 2 - then (throw "Signature must at least have two types (a -> b)") - else defun' sig func; -in (typeSet [ - # Primitive types - (typedef "any" (_: true)) - (typedef "int" isInt) - (typedef "bool" isBool) - (typedef "float" isFloat) - (typedef "string" isString) - (typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation")) - (typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" - && isFunction x.__functor))) - # Polymorphic types - (poly "option" (t: v: (isNull v) || t.check v)) - (poly "list" (t: v: isList v && (foldl' (s: e: s && ( - if t.check e then true - else throw "Expected list element of type '${t.name}', but '${toPretty e}' is of type '${typeOf e}'" - )) true v))) + # Structs / record types + # + # Checks that all fields match their declared types, no optional + # fields are missing and no unexpected fields occur in the struct. + # + # Anonymous structs are supported (e.g. for nesting) by omitting the + # name. + # + # TODO: Support open records? + struct = + # Struct checking is more involved than the simpler types above. + # To make the actual type definition more readable, several + # helpers are defined below. + let + # checkField checks an individual field of the struct against + # its definition and creates a typecheck result. These results + # are aggregated during the actual checking. + checkField = def: name: value: let result = def.checkType value; in rec { + ok = def.checkToBool result; + err = if !ok && isNull value + then "missing required ${def.name} field '${name}'\n" + else "field '${name}': ${def.toError value result}\n"; + }; + + # checkExtraneous determines whether a (closed) struct contains + # any fields that are not part of the definition. + checkExtraneous = def: has: acc: + if (length has) == 0 then acc + else if (hasAttr (head has) def) + then checkExtraneous def (tail has) acc + else checkExtraneous def (tail has) { + ok = false; + err = acc.err + "unexpected struct field '${head has}'\n"; + }; + + # checkStruct combines all structure checks and creates one + # typecheck result from them + checkStruct = def: value: + let + init = { ok = true; err = ""; }; + extraneous = checkExtraneous def (attrNames value) init; + + checkedFields = map (n: + let v = if hasAttr n value then value."${n}" else null; + in checkField def."${n}" n v) (attrNames def); + + combined = foldl' (acc: res: { + ok = acc.ok && res.ok; + err = if !res.ok then acc.err + res.err else acc.err; + }) init checkedFields; + in { + ok = combined.ok && extraneous.ok; + err = combined.err + extraneous.err; + }; + + struct' = name: def: typedef' { + inherit name def; + checkType = value: if isAttrs value + then (checkStruct (self.attrs self.type def) value) + else { ok = false; err = typeError name value; }; + + toError = _: result: "expected '${name}'-struct, but found:\n" + result.err; + }; + in arg: if isString arg then (struct' arg) else (struct' "anon" arg); + + # Enums & pattern matching + enum = + let + plain = name: def: typedef' { + inherit name def; + + checkType = (x: isString x && elem x def); + checkToBool = x: x; + toError = value: _: "'${prettyPrint value} is not a member of enum ${name}"; + }; + enum' = name: def: lib.fix (e: (plain name def) // { + match = x: actions: deepSeq (map e (attrNames actions)) ( + let + actionKeys = attrNames actions; + missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] def; + in if (length missing) > 0 + then throw "Missing match action for members: ${prettyPrint missing}" + else actions."${e x}"); + }); + in arg: if isString arg then (enum' arg) else (enum' "anon" arg); + + # Sum types + # + # The representation of a sum type is an attribute set with only one + # value, where the key of the value denotes the variant of the type. + sum = + let + plain = name: def: typedef' { + inherit name def; + checkType = (x: + let variant = elemAt (attrNames x) 0; + in if isAttrs x && length (attrNames x) == 1 && hasAttr variant def + then let t = def."${variant}"; + v = x."${variant}"; + res = t.checkType v; + in if t.checkToBool res + then { ok = true; } + else { + ok = false; + err = "while checking '${name}' variant '${variant}': " + + t.toError v res; + } + else { ok = false; err = typeError name x; } + ); + }; + sum' = name: def: lib.fix (s: (plain name def) // { + match = x: actions: + let variant = deepSeq (s x) (elemAt (attrNames x) 0); + actionKeys = attrNames actions; + defKeys = attrNames def; + missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] defKeys; + in if (length missing) > 0 + then throw "Missing match action for variants: ${prettyPrint missing}" + else actions."${variant}" x."${variant}"; + }); + in arg: if isString arg then (sum' arg) else (sum' "anon" arg); + + # Typed function definitions + # + # These definitions wrap the supplied function in type-checking + # forms that are evaluated when the function is called. + # + # Note that typed functions themselves are not types and can not be + # used to check values for conformity. + defun = + let + mkFunc = sig: f: { + inherit sig; + __toString = self: foldl' (s: t: "${s} -> ${t.name}") + "λ :: ${(head self.sig).name}" (tail self.sig); + __functor = _: f; + }; - (poly "attrs" (t: v: isAttrs v && (foldl' (s: e: s && ( - if t.check e then true - else throw "Expected attribute set element of type '${t.name}', but '${toPretty e}' is of type '${typeOf e}'" - )) true (attrValues v)))) + defun' = sig: func: if length sig > 2 + then mkFunc sig (x: defun' (tail sig) (func ((head sig) x))) + else mkFunc sig (x: ((head (tail sig)) (func ((head sig) x)))); - (poly2 "either" (t1: t2: v: t1.check v || t2.check v)) -]) // { inherit struct enum sum defun; } + in sig: func: if length sig < 2 + then (throw "Signature must at least have two types (a -> b)") + else defun' sig func; +}) -- cgit 1.4.1 From cb45536124ce5cd1f34dc16bc853ecaaf8f08980 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 14:31:45 +0100 Subject: test: Add a test to check that all types match the 'type'-type --- z-yants-tests.nix | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/z-yants-tests.nix b/z-yants-tests.nix index f468f61322..b97d058c04 100644 --- a/z-yants-tests.nix +++ b/z-yants-tests.nix @@ -1,5 +1,5 @@ -with (import ./yants.nix {}); with builtins; +with (import ./yants.nix {}); # Note: Derivations are not included in the tests below as they cause # issues with deepSeq. @@ -68,4 +68,18 @@ deepSeq rec { (name: age: "${name} is ${toString age} years old"); testFunc = func "Brynhjulf" 42; + + # Test that all types are types. + testTypes = map type [ + any bool drv float int string + + (attrs int) + (either int string) + (enum [ "foo" "bar" ]) + (list string) + (option int) + (option (list string)) + (struct { a = int; b = option string; }) + (sum { a = int; b = option string; }) + ]; } "All tests passed!\n" -- cgit 1.4.1 From 34a591798179c87b84692712398359609a18c513 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 14:33:41 +0100 Subject: test: Add test for pattern matching on sum types --- z-yants-tests.nix | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/z-yants-tests.nix b/z-yants-tests.nix index b97d058c04..e1e521c5ab 100644 --- a/z-yants-tests.nix +++ b/z-yants-tests.nix @@ -63,6 +63,11 @@ deepSeq rec { }; }; + testSumMatch = creature.match testSum { + human = v: "It's a human named ${v.name}"; + pet = v: throw "It's not supposed to be a pet!"; + }; + # Test curried function definitions func = defun [ string int string ] (name: age: "${name} is ${toString age} years old"); -- cgit 1.4.1 From 6468845255e5516d4567f9bef48d815549b20910 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 14:53:55 +0100 Subject: chore: Change file layout to match repository instead of gist --- README.md | 40 ++++++ default.nix | 295 +++++++++++++++++++++++++++++++++++++++++ screenshots/enums.png | Bin 0 -> 41305 bytes screenshots/functions.png | Bin 0 -> 32907 bytes screenshots/nested-structs.png | Bin 0 -> 70264 bytes screenshots/simple.png | Bin 0 -> 43010 bytes screenshots/structs.png | Bin 0 -> 69499 bytes tests.nix | 90 +++++++++++++ yants.md | 38 ------ yants.nix | 295 ----------------------------------------- z-enums.png | Bin 41305 -> 0 bytes z-functions.png | Bin 32907 -> 0 bytes z-nested-structs.png | Bin 70264 -> 0 bytes z-simple.png | Bin 43010 -> 0 bytes z-structs.png | Bin 69499 -> 0 bytes z-yants-tests.nix | 90 ------------- 16 files changed, 425 insertions(+), 423 deletions(-) create mode 100644 README.md create mode 100644 default.nix create mode 100644 screenshots/enums.png create mode 100644 screenshots/functions.png create mode 100644 screenshots/nested-structs.png create mode 100644 screenshots/simple.png create mode 100644 screenshots/structs.png create mode 100644 tests.nix delete mode 100644 yants.md delete mode 100644 yants.nix delete mode 100644 z-enums.png delete mode 100644 z-functions.png delete mode 100644 z-nested-structs.png delete mode 100644 z-simple.png delete mode 100644 z-structs.png delete mode 100644 z-yants-tests.nix diff --git a/README.md b/README.md new file mode 100644 index 0000000000..55ea764d8f --- /dev/null +++ b/README.md @@ -0,0 +1,40 @@ +yants +===== + +This is a tiny type-checker for data in Nix, written in Nix. + +Features: + +* Checking of primitive types (`int`, `string` etc.) +* Checking polymorphic types (`option`, `list`, `either`) +* Defining & checking struct/record types +* Defining & matching enum types +* Defining & matching sum types +* Defining function signatures (including curried functions) +* Types are composable! `option string`! `list (either int (option float))`! +* Type errors also compose! + +Lacking: + +* Any kind of inference +* Convenient syntax for attribute-set function signatures + +## Primitives & simple polymorphism + +![simple](screenshots/simple.png) + +## Structs + +![structs](screenshots/structs.png) + +## Nested structs! + +![nested structs](screenshots/nested-structs.png) + +## Enums! + +![enums](screenshots/enums.png) + +## Functions! + +![functions](screenshots/functions.png) diff --git a/default.nix b/default.nix new file mode 100644 index 0000000000..17564b61b9 --- /dev/null +++ b/default.nix @@ -0,0 +1,295 @@ +# Copyright 2019 Google LLC +# SPDX-License-Identifier: Apache-2.0 +# +# Provides a "type-system" for Nix that provides various primitive & +# polymorphic types as well as the ability to define & check records. +# +# All types (should) compose as expected. + +{ lib ? (import {}).lib }: + +with builtins; let + prettyPrint = lib.generators.toPretty {}; + + # typedef' :: struct { + # name = string; + # checkType = function; (a -> result) + # checkToBool = option function; (result -> bool) + # toError = option function; (a -> result -> string) + # def = option any; + # match = option function; + # } -> type + # -> (a -> b) + # -> (b -> bool) + # -> (a -> b -> string) + # -> type + # + # This function creates an attribute set that acts as a type. + # + # It receives a type name, a function that is used to perform a + # check on an arbitrary value, a function that can translate the + # return of that check to a boolean that informs whether the value + # is type-conformant, and a function that can construct error + # messages from the check result. + # + # This function is the low-level primitive used to create types. For + # many cases the higher-level 'typedef' function is more appropriate. + typedef' = { name, checkType + , checkToBool ? (result: result.ok) + , toError ? (_: result: result.err) + , def ? null + , match ? null }: { + inherit name checkToBool toError; + + # check :: a -> bool + # + # This function is used to determine whether a given type is + # conformant. + check = value: checkToBool (checkType value); + + # checkType :: a -> struct { ok = bool; err = option string; } + # + # This function checks whether the passed value is type conformant + # and returns an optional type error string otherwise. + inherit checkType; + + # __functor :: a -> a + # + # This function checks whether the passed value is type conformant + # and throws an error if it is not. + # + # The name of this function is a special attribute in Nix that + # makes it possible to execute a type attribute set like a normal + # function. + __functor = self: value: + let result = self.checkType value; + in if checkToBool result then value + else throw (toError value result); + }; + + typeError = type: val: + "expected type '${type}', but value '${prettyPrint val}' is of type '${typeOf val}'"; + + # typedef :: string -> (a -> bool) -> type + # + # typedef is the simplified version of typedef' which uses a default + # error message constructor. + typedef = name: check: typedef' { + inherit name; + checkType = check; + checkToBool = r: r; + toError = value: _result: typeError name value; + }; + + checkEach = name: t: l: foldl' (acc: e: + let res = t.checkType e; + isT = t.checkToBool res; + in { + ok = acc.ok && isT; + err = if isT + then acc.err + else acc.err + "${prettyPrint e}: ${t.toError e res}\n"; + }) { ok = true; err = "expected type ${name}, but found:\n"; } l; +in lib.fix (self: { + # Primitive types + any = typedef "any" (_: true); + int = typedef "int" isInt; + bool = typedef "bool" isBool; + float = typedef "float" isFloat; + string = typedef "string" isString; + drv = typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation"); + function = typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" + && isFunction x.__functor)); + + # Type for types themselves. Useful when defining polymorphic types. + type = typedef "type" (x: + isAttrs x + && hasAttr "name" x && self.string.check x.name + && hasAttr "checkType" x && self.function.check x.checkType + && hasAttr "checkToBool" x && self.function.check x.checkToBool + && hasAttr "toError" x && self.function.check x.toError + ); + + # Polymorphic types + option = t: typedef' rec { + name = "option<${t.name}>"; + checkType = v: + let res = t.checkType v; + in { + ok = isNull v || (self.type t).checkToBool res; + err = "expected type ${name}, but value does not conform to '${t.name}': " + + t.toError v res; + }; + }; + + either = t1: t2: typedef "either<${t1.name},${t2.name}>" + (x: (self.type t1).check x || (self.type t2).check x); + + list = t: typedef' rec { + name = "list<${t.name}>"; + + checkType = v: if isList v + then checkEach name (self.type t) v + else { + ok = false; + err = typeError name v; + }; + }; + + attrs = t: typedef' rec { + name = "attrs<${t.name}>"; + + checkType = v: if isAttrs v + then checkEach name (self.type t) (attrValues v) + else { + ok = false; + err = typeError name v; + }; + }; + + # Structs / record types + # + # Checks that all fields match their declared types, no optional + # fields are missing and no unexpected fields occur in the struct. + # + # Anonymous structs are supported (e.g. for nesting) by omitting the + # name. + # + # TODO: Support open records? + struct = + # Struct checking is more involved than the simpler types above. + # To make the actual type definition more readable, several + # helpers are defined below. + let + # checkField checks an individual field of the struct against + # its definition and creates a typecheck result. These results + # are aggregated during the actual checking. + checkField = def: name: value: let result = def.checkType value; in rec { + ok = def.checkToBool result; + err = if !ok && isNull value + then "missing required ${def.name} field '${name}'\n" + else "field '${name}': ${def.toError value result}\n"; + }; + + # checkExtraneous determines whether a (closed) struct contains + # any fields that are not part of the definition. + checkExtraneous = def: has: acc: + if (length has) == 0 then acc + else if (hasAttr (head has) def) + then checkExtraneous def (tail has) acc + else checkExtraneous def (tail has) { + ok = false; + err = acc.err + "unexpected struct field '${head has}'\n"; + }; + + # checkStruct combines all structure checks and creates one + # typecheck result from them + checkStruct = def: value: + let + init = { ok = true; err = ""; }; + extraneous = checkExtraneous def (attrNames value) init; + + checkedFields = map (n: + let v = if hasAttr n value then value."${n}" else null; + in checkField def."${n}" n v) (attrNames def); + + combined = foldl' (acc: res: { + ok = acc.ok && res.ok; + err = if !res.ok then acc.err + res.err else acc.err; + }) init checkedFields; + in { + ok = combined.ok && extraneous.ok; + err = combined.err + extraneous.err; + }; + + struct' = name: def: typedef' { + inherit name def; + checkType = value: if isAttrs value + then (checkStruct (self.attrs self.type def) value) + else { ok = false; err = typeError name value; }; + + toError = _: result: "expected '${name}'-struct, but found:\n" + result.err; + }; + in arg: if isString arg then (struct' arg) else (struct' "anon" arg); + + # Enums & pattern matching + enum = + let + plain = name: def: typedef' { + inherit name def; + + checkType = (x: isString x && elem x def); + checkToBool = x: x; + toError = value: _: "'${prettyPrint value} is not a member of enum ${name}"; + }; + enum' = name: def: lib.fix (e: (plain name def) // { + match = x: actions: deepSeq (map e (attrNames actions)) ( + let + actionKeys = attrNames actions; + missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] def; + in if (length missing) > 0 + then throw "Missing match action for members: ${prettyPrint missing}" + else actions."${e x}"); + }); + in arg: if isString arg then (enum' arg) else (enum' "anon" arg); + + # Sum types + # + # The representation of a sum type is an attribute set with only one + # value, where the key of the value denotes the variant of the type. + sum = + let + plain = name: def: typedef' { + inherit name def; + checkType = (x: + let variant = elemAt (attrNames x) 0; + in if isAttrs x && length (attrNames x) == 1 && hasAttr variant def + then let t = def."${variant}"; + v = x."${variant}"; + res = t.checkType v; + in if t.checkToBool res + then { ok = true; } + else { + ok = false; + err = "while checking '${name}' variant '${variant}': " + + t.toError v res; + } + else { ok = false; err = typeError name x; } + ); + }; + sum' = name: def: lib.fix (s: (plain name def) // { + match = x: actions: + let variant = deepSeq (s x) (elemAt (attrNames x) 0); + actionKeys = attrNames actions; + defKeys = attrNames def; + missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] defKeys; + in if (length missing) > 0 + then throw "Missing match action for variants: ${prettyPrint missing}" + else actions."${variant}" x."${variant}"; + }); + in arg: if isString arg then (sum' arg) else (sum' "anon" arg); + + # Typed function definitions + # + # These definitions wrap the supplied function in type-checking + # forms that are evaluated when the function is called. + # + # Note that typed functions themselves are not types and can not be + # used to check values for conformity. + defun = + let + mkFunc = sig: f: { + inherit sig; + __toString = self: foldl' (s: t: "${s} -> ${t.name}") + "λ :: ${(head self.sig).name}" (tail self.sig); + __functor = _: f; + }; + + defun' = sig: func: if length sig > 2 + then mkFunc sig (x: defun' (tail sig) (func ((head sig) x))) + else mkFunc sig (x: ((head (tail sig)) (func ((head sig) x)))); + + in sig: func: if length sig < 2 + then (throw "Signature must at least have two types (a -> b)") + else defun' sig func; +}) diff --git a/screenshots/enums.png b/screenshots/enums.png new file mode 100644 index 0000000000..71673e7ab6 Binary files /dev/null and b/screenshots/enums.png differ diff --git a/screenshots/functions.png b/screenshots/functions.png new file mode 100644 index 0000000000..30ed50f832 Binary files /dev/null and b/screenshots/functions.png differ diff --git a/screenshots/nested-structs.png b/screenshots/nested-structs.png new file mode 100644 index 0000000000..6b03ed65ce Binary files /dev/null and b/screenshots/nested-structs.png differ diff --git a/screenshots/simple.png b/screenshots/simple.png new file mode 100644 index 0000000000..05a302cc6b Binary files /dev/null and b/screenshots/simple.png differ diff --git a/screenshots/structs.png b/screenshots/structs.png new file mode 100644 index 0000000000..fcbcf6415f Binary files /dev/null and b/screenshots/structs.png differ diff --git a/tests.nix b/tests.nix new file mode 100644 index 0000000000..344f2c1f59 --- /dev/null +++ b/tests.nix @@ -0,0 +1,90 @@ +with builtins; +with (import ./default.nix {}); + +# Note: Derivations are not included in the tests below as they cause +# issues with deepSeq. + +deepSeq rec { + # Test that all primitive types match + primitives = [ + (int 15) + (bool false) + (float 13.37) + (string "Hello!") + (function (x: x * 2)) + ]; + + # Test that polymorphic types work as intended + poly = [ + (option int null) + (list string [ "foo" "bar" ]) + (either int float 42) + ]; + + # Test that structures work as planned. + person = struct "person" { + name = string; + age = int; + + contact = option (struct { + email = string; + phone = option string; + }); + }; + + testPerson = person { + name = "Brynhjulf"; + age = 42; + contact.email = "brynhjulf@yants.nix"; + }; + + # Test enum definitions & matching + colour = enum "colour" [ "red" "blue" "green" ]; + testMatch = colour.match "red" { + red = "It is in fact red!"; + blue = throw "It should not be blue!"; + green = throw "It should not be green!"; + }; + + # Test sum type definitions + creature = sum "creature" { + human = struct { + name = string; + age = option int; + }; + + pet = enum "pet" [ "dog" "lizard" "cat" ]; + }; + + testSum = creature { + human = { + name = "Brynhjulf"; + age = 42; + }; + }; + + testSumMatch = creature.match testSum { + human = v: "It's a human named ${v.name}"; + pet = v: throw "It's not supposed to be a pet!"; + }; + + # Test curried function definitions + func = defun [ string int string ] + (name: age: "${name} is ${toString age} years old"); + + testFunc = func "Brynhjulf" 42; + + # Test that all types are types. + testTypes = map type [ + any bool drv float int string + + (attrs int) + (either int string) + (enum [ "foo" "bar" ]) + (list string) + (option int) + (option (list string)) + (struct { a = int; b = option string; }) + (sum { a = int; b = option string; }) + ]; +} "All tests passed!\n" diff --git a/yants.md b/yants.md deleted file mode 100644 index e10e120f08..0000000000 --- a/yants.md +++ /dev/null @@ -1,38 +0,0 @@ -yants -===== - -This is a tiny type-checker for data in Nix, written in Nix. - -Features: - -* Checking of primitive types (`int`, `string` etc.) -* Checking polymorphic types (`option`, `list`, `either`) -* Defining & checking struct/record types -* Defining & matching enum types -* Defining function signatures (including curried functions) -* Types are composable! `option string`! `list (either int (option float))`! - -Lacking: - -* Any kind of inference (Nix's reflection ability is not strong enough) -* Convenient syntax for attribute-set function signatures - -## Primitives & simple polymorphism - -![simple](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7b1fa0a511ae40f0831b369df4b97103441c7e5/z-simple.png) - -## Structs - -![structs](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7a7cff3639115538a5085561bedf11cb36d04e7/z-structs.png) - -## Nested structs! - -![nested structs](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/d7b1fa0a511ae40f0831b369df4b97103441c7e5/z-nested-structs.png) - -## Enums! - -![enums](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/b435b5996a176a9e824c42da4713a1d30f261338/z-enums.png) - -## Functions! - -![functions](https://gist.githubusercontent.com/tazjin/ad6d48bc2416335acc5da4a197eb9ddc/raw/ccece1eb9a1cb3b1add1ba1a1f65df3adca64a8f/z-functions.png) diff --git a/yants.nix b/yants.nix deleted file mode 100644 index 17564b61b9..0000000000 --- a/yants.nix +++ /dev/null @@ -1,295 +0,0 @@ -# Copyright 2019 Google LLC -# SPDX-License-Identifier: Apache-2.0 -# -# Provides a "type-system" for Nix that provides various primitive & -# polymorphic types as well as the ability to define & check records. -# -# All types (should) compose as expected. - -{ lib ? (import {}).lib }: - -with builtins; let - prettyPrint = lib.generators.toPretty {}; - - # typedef' :: struct { - # name = string; - # checkType = function; (a -> result) - # checkToBool = option function; (result -> bool) - # toError = option function; (a -> result -> string) - # def = option any; - # match = option function; - # } -> type - # -> (a -> b) - # -> (b -> bool) - # -> (a -> b -> string) - # -> type - # - # This function creates an attribute set that acts as a type. - # - # It receives a type name, a function that is used to perform a - # check on an arbitrary value, a function that can translate the - # return of that check to a boolean that informs whether the value - # is type-conformant, and a function that can construct error - # messages from the check result. - # - # This function is the low-level primitive used to create types. For - # many cases the higher-level 'typedef' function is more appropriate. - typedef' = { name, checkType - , checkToBool ? (result: result.ok) - , toError ? (_: result: result.err) - , def ? null - , match ? null }: { - inherit name checkToBool toError; - - # check :: a -> bool - # - # This function is used to determine whether a given type is - # conformant. - check = value: checkToBool (checkType value); - - # checkType :: a -> struct { ok = bool; err = option string; } - # - # This function checks whether the passed value is type conformant - # and returns an optional type error string otherwise. - inherit checkType; - - # __functor :: a -> a - # - # This function checks whether the passed value is type conformant - # and throws an error if it is not. - # - # The name of this function is a special attribute in Nix that - # makes it possible to execute a type attribute set like a normal - # function. - __functor = self: value: - let result = self.checkType value; - in if checkToBool result then value - else throw (toError value result); - }; - - typeError = type: val: - "expected type '${type}', but value '${prettyPrint val}' is of type '${typeOf val}'"; - - # typedef :: string -> (a -> bool) -> type - # - # typedef is the simplified version of typedef' which uses a default - # error message constructor. - typedef = name: check: typedef' { - inherit name; - checkType = check; - checkToBool = r: r; - toError = value: _result: typeError name value; - }; - - checkEach = name: t: l: foldl' (acc: e: - let res = t.checkType e; - isT = t.checkToBool res; - in { - ok = acc.ok && isT; - err = if isT - then acc.err - else acc.err + "${prettyPrint e}: ${t.toError e res}\n"; - }) { ok = true; err = "expected type ${name}, but found:\n"; } l; -in lib.fix (self: { - # Primitive types - any = typedef "any" (_: true); - int = typedef "int" isInt; - bool = typedef "bool" isBool; - float = typedef "float" isFloat; - string = typedef "string" isString; - drv = typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation"); - function = typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" - && isFunction x.__functor)); - - # Type for types themselves. Useful when defining polymorphic types. - type = typedef "type" (x: - isAttrs x - && hasAttr "name" x && self.string.check x.name - && hasAttr "checkType" x && self.function.check x.checkType - && hasAttr "checkToBool" x && self.function.check x.checkToBool - && hasAttr "toError" x && self.function.check x.toError - ); - - # Polymorphic types - option = t: typedef' rec { - name = "option<${t.name}>"; - checkType = v: - let res = t.checkType v; - in { - ok = isNull v || (self.type t).checkToBool res; - err = "expected type ${name}, but value does not conform to '${t.name}': " - + t.toError v res; - }; - }; - - either = t1: t2: typedef "either<${t1.name},${t2.name}>" - (x: (self.type t1).check x || (self.type t2).check x); - - list = t: typedef' rec { - name = "list<${t.name}>"; - - checkType = v: if isList v - then checkEach name (self.type t) v - else { - ok = false; - err = typeError name v; - }; - }; - - attrs = t: typedef' rec { - name = "attrs<${t.name}>"; - - checkType = v: if isAttrs v - then checkEach name (self.type t) (attrValues v) - else { - ok = false; - err = typeError name v; - }; - }; - - # Structs / record types - # - # Checks that all fields match their declared types, no optional - # fields are missing and no unexpected fields occur in the struct. - # - # Anonymous structs are supported (e.g. for nesting) by omitting the - # name. - # - # TODO: Support open records? - struct = - # Struct checking is more involved than the simpler types above. - # To make the actual type definition more readable, several - # helpers are defined below. - let - # checkField checks an individual field of the struct against - # its definition and creates a typecheck result. These results - # are aggregated during the actual checking. - checkField = def: name: value: let result = def.checkType value; in rec { - ok = def.checkToBool result; - err = if !ok && isNull value - then "missing required ${def.name} field '${name}'\n" - else "field '${name}': ${def.toError value result}\n"; - }; - - # checkExtraneous determines whether a (closed) struct contains - # any fields that are not part of the definition. - checkExtraneous = def: has: acc: - if (length has) == 0 then acc - else if (hasAttr (head has) def) - then checkExtraneous def (tail has) acc - else checkExtraneous def (tail has) { - ok = false; - err = acc.err + "unexpected struct field '${head has}'\n"; - }; - - # checkStruct combines all structure checks and creates one - # typecheck result from them - checkStruct = def: value: - let - init = { ok = true; err = ""; }; - extraneous = checkExtraneous def (attrNames value) init; - - checkedFields = map (n: - let v = if hasAttr n value then value."${n}" else null; - in checkField def."${n}" n v) (attrNames def); - - combined = foldl' (acc: res: { - ok = acc.ok && res.ok; - err = if !res.ok then acc.err + res.err else acc.err; - }) init checkedFields; - in { - ok = combined.ok && extraneous.ok; - err = combined.err + extraneous.err; - }; - - struct' = name: def: typedef' { - inherit name def; - checkType = value: if isAttrs value - then (checkStruct (self.attrs self.type def) value) - else { ok = false; err = typeError name value; }; - - toError = _: result: "expected '${name}'-struct, but found:\n" + result.err; - }; - in arg: if isString arg then (struct' arg) else (struct' "anon" arg); - - # Enums & pattern matching - enum = - let - plain = name: def: typedef' { - inherit name def; - - checkType = (x: isString x && elem x def); - checkToBool = x: x; - toError = value: _: "'${prettyPrint value} is not a member of enum ${name}"; - }; - enum' = name: def: lib.fix (e: (plain name def) // { - match = x: actions: deepSeq (map e (attrNames actions)) ( - let - actionKeys = attrNames actions; - missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] def; - in if (length missing) > 0 - then throw "Missing match action for members: ${prettyPrint missing}" - else actions."${e x}"); - }); - in arg: if isString arg then (enum' arg) else (enum' "anon" arg); - - # Sum types - # - # The representation of a sum type is an attribute set with only one - # value, where the key of the value denotes the variant of the type. - sum = - let - plain = name: def: typedef' { - inherit name def; - checkType = (x: - let variant = elemAt (attrNames x) 0; - in if isAttrs x && length (attrNames x) == 1 && hasAttr variant def - then let t = def."${variant}"; - v = x."${variant}"; - res = t.checkType v; - in if t.checkToBool res - then { ok = true; } - else { - ok = false; - err = "while checking '${name}' variant '${variant}': " - + t.toError v res; - } - else { ok = false; err = typeError name x; } - ); - }; - sum' = name: def: lib.fix (s: (plain name def) // { - match = x: actions: - let variant = deepSeq (s x) (elemAt (attrNames x) 0); - actionKeys = attrNames actions; - defKeys = attrNames def; - missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] defKeys; - in if (length missing) > 0 - then throw "Missing match action for variants: ${prettyPrint missing}" - else actions."${variant}" x."${variant}"; - }); - in arg: if isString arg then (sum' arg) else (sum' "anon" arg); - - # Typed function definitions - # - # These definitions wrap the supplied function in type-checking - # forms that are evaluated when the function is called. - # - # Note that typed functions themselves are not types and can not be - # used to check values for conformity. - defun = - let - mkFunc = sig: f: { - inherit sig; - __toString = self: foldl' (s: t: "${s} -> ${t.name}") - "λ :: ${(head self.sig).name}" (tail self.sig); - __functor = _: f; - }; - - defun' = sig: func: if length sig > 2 - then mkFunc sig (x: defun' (tail sig) (func ((head sig) x))) - else mkFunc sig (x: ((head (tail sig)) (func ((head sig) x)))); - - in sig: func: if length sig < 2 - then (throw "Signature must at least have two types (a -> b)") - else defun' sig func; -}) diff --git a/z-enums.png b/z-enums.png deleted file mode 100644 index 71673e7ab6..0000000000 Binary files a/z-enums.png and /dev/null differ diff --git a/z-functions.png b/z-functions.png deleted file mode 100644 index 30ed50f832..0000000000 Binary files a/z-functions.png and /dev/null differ diff --git a/z-nested-structs.png b/z-nested-structs.png deleted file mode 100644 index 6b03ed65ce..0000000000 Binary files a/z-nested-structs.png and /dev/null differ diff --git a/z-simple.png b/z-simple.png deleted file mode 100644 index 05a302cc6b..0000000000 Binary files a/z-simple.png and /dev/null differ diff --git a/z-structs.png b/z-structs.png deleted file mode 100644 index fcbcf6415f..0000000000 Binary files a/z-structs.png and /dev/null differ diff --git a/z-yants-tests.nix b/z-yants-tests.nix deleted file mode 100644 index e1e521c5ab..0000000000 --- a/z-yants-tests.nix +++ /dev/null @@ -1,90 +0,0 @@ -with builtins; -with (import ./yants.nix {}); - -# Note: Derivations are not included in the tests below as they cause -# issues with deepSeq. - -deepSeq rec { - # Test that all primitive types match - primitives = [ - (int 15) - (bool false) - (float 13.37) - (string "Hello!") - (function (x: x * 2)) - ]; - - # Test that polymorphic types work as intended - poly = [ - (option int null) - (list string [ "foo" "bar" ]) - (either int float 42) - ]; - - # Test that structures work as planned. - person = struct "person" { - name = string; - age = int; - - contact = option (struct { - email = string; - phone = option string; - }); - }; - - testPerson = person { - name = "Brynhjulf"; - age = 42; - contact.email = "brynhjulf@yants.nix"; - }; - - # Test enum definitions & matching - colour = enum "colour" [ "red" "blue" "green" ]; - testMatch = colour.match "red" { - red = "It is in fact red!"; - blue = throw "It should not be blue!"; - green = throw "It should not be green!"; - }; - - # Test sum type definitions - creature = sum "creature" { - human = struct { - name = string; - age = option int; - }; - - pet = enum "pet" [ "dog" "lizard" "cat" ]; - }; - - testSum = creature { - human = { - name = "Brynhjulf"; - age = 42; - }; - }; - - testSumMatch = creature.match testSum { - human = v: "It's a human named ${v.name}"; - pet = v: throw "It's not supposed to be a pet!"; - }; - - # Test curried function definitions - func = defun [ string int string ] - (name: age: "${name} is ${toString age} years old"); - - testFunc = func "Brynhjulf" 42; - - # Test that all types are types. - testTypes = map type [ - any bool drv float int string - - (attrs int) - (either int string) - (enum [ "foo" "bar" ]) - (list string) - (option int) - (option (list string)) - (struct { a = int; b = option string; }) - (sum { a = int; b = option string; }) - ]; -} "All tests passed!\n" -- cgit 1.4.1 From 0c1a6b88dd1231dbff00805ac723a06c39211a22 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 14:55:56 +0100 Subject: feat: Add Travis CI configuration --- .travis.yml | 3 +++ 1 file changed, 3 insertions(+) create mode 100644 .travis.yml diff --git a/.travis.yml b/.travis.yml new file mode 100644 index 0000000000..0d998d034f --- /dev/null +++ b/.travis.yml @@ -0,0 +1,3 @@ +language: nix +script: + - nix eval --raw '(import ./tests.nix)' --show-trace -- cgit 1.4.1 From d53f7f134b3f77db652a9cef006ffbc4261914d9 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 15:02:39 +0100 Subject: docs: Add build status to README --- README.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/README.md b/README.md index 55ea764d8f..383ae1788b 100644 --- a/README.md +++ b/README.md @@ -1,6 +1,8 @@ yants ===== +[![Build Status](https://travis-ci.org/tazjin/yants.svg?branch=master)](https://travis-ci.org/tazjin/yants) + This is a tiny type-checker for data in Nix, written in Nix. Features: -- cgit 1.4.1 From 10a93400f89d565cbef16a3cda62267b112f8f3f Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 15:03:01 +0100 Subject: chore: Add Apache License 2.0 --- LICENSE | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 LICENSE diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000000..d645695673 --- /dev/null +++ b/LICENSE @@ -0,0 +1,202 @@ + + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. 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In no event and under no legal theory, + whether in tort (including negligence), contract, or otherwise, + unless required by applicable law (such as deliberate and grossly + negligent acts) or agreed to in writing, shall any Contributor be + liable to You for damages, including any direct, indirect, special, + incidental, or consequential damages of any character arising as a + result of this License or out of the use or inability to use the + Work (including but not limited to damages for loss of goodwill, + work stoppage, computer failure or malfunction, or any and all + other commercial damages or losses), even if such Contributor + has been advised of the possibility of such damages. + + 9. Accepting Warranty or Additional Liability. While redistributing + the Work or Derivative Works thereof, You may choose to offer, + and charge a fee for, acceptance of support, warranty, indemnity, + or other liability obligations and/or rights consistent with this + License. However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + + END OF TERMS AND CONDITIONS + + APPENDIX: How to apply the Apache License to your work. + + To apply the Apache License to your work, attach the following + boilerplate notice, with the fields enclosed by brackets "[]" + replaced with your own identifying information. (Don't include + the brackets!) The text should be enclosed in the appropriate + comment syntax for the file format. We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + + Copyright [yyyy] [name of copyright owner] + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. -- cgit 1.4.1 From f3c66e172cce8c918c0d130073c37ce0dbde4025 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Wed, 28 Aug 2019 15:06:43 +0100 Subject: chore: Add contribution & code of conduct information --- CODE_OF_CONDUCT.md | 20 ++++++++++ CONTRIBUTING.md | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 135 insertions(+) create mode 100644 CODE_OF_CONDUCT.md create mode 100644 CONTRIBUTING.md diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md new file mode 100644 index 0000000000..c4013ac13e --- /dev/null +++ b/CODE_OF_CONDUCT.md @@ -0,0 +1,20 @@ +A SERMON ON ETHICS AND LOVE +=========================== + +One day Mal-2 asked the messenger spirit Saint Gulik to approach the Goddess and request Her presence for some desperate advice. Shortly afterwards the radio came on by itself, and an ethereal female Voice said **YES?** + +"O! Eris! Blessed Mother of Man! Queen of Chaos! Daughter of Discord! Concubine of Confusion! O! Exquisite Lady, I beseech You to lift a heavy burden from my heart!" + +**WHAT BOTHERS YOU, MAL? YOU DON'T SOUND WELL.** + +"I am filled with fear and tormented with terrible visions of pain. Everywhere people are hurting one another, the planet is rampant with injustices, whole societies plunder groups of their own people, mothers imprison sons, children perish while brothers war. O, woe." + +**WHAT IS THE MATTER WITH THAT, IF IT IS WHAT YOU WANT TO DO?** + +"But nobody Wants it! Everybody hates it." + +**OH. WELL, THEN *STOP*.** + +At which moment She turned herself into an aspirin commercial and left The Polyfather stranded alone with his species. + +SINISTER DEXTER HAS A BROKEN SPIROMETER. diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md new file mode 100644 index 0000000000..fb5f8210dd --- /dev/null +++ b/CONTRIBUTING.md @@ -0,0 +1,115 @@ +Contribution Guidelines +======================= + + +**Table of Contents** + +- [Contribution Guidelines](#contribution-guidelines) + - [Before making a change](#before-making-a-change) + - [Commit messages](#commit-messages) + - [Commit content](#commit-content) + - [Code quality](#code-quality) + - [Builds & tests](#builds--tests) + + + +This is a loose set of "guidelines" for contributing to my projects. +Please note that I will not accept any pull requests that don't follow +these guidelines. + +Also consider the [code of conduct](CODE_OF_CONDUCT.md). No really, +you should. + +## Before making a change + +Before making a change, consider your motivation for making the +change. Documentation updates, bug fixes and the like are *always* +welcome. + +When adding a feature you should consider whether it is only useful +for your particular use-case or whether it is generally applicable for +other users of the project. + +When in doubt - just ask me! + +## Commit messages + +All commit messages should follow the style-guide used by the [Angular +project][]. This means for the most part that your commit message +should be structured like this: + +``` +type(scope): Subject line with at most 68 a character length + +Body of the commit message with an empty line between subject and +body. This text should explain what the change does and why it has +been made, *especially* if it introduces a new feature. + +Relevant issues should be mentioned if they exist. +``` + +Where `type` can be one of: + +* `feat`: A new feature has been introduced +* `fix`: An issue of some kind has been fixed +* `docs`: Documentation or comments have been updated +* `style`: Formatting changes only +* `refactor`: Hopefully self-explanatory! +* `test`: Added missing tests / fixed tests +* `chore`: Maintenance work + +And `scope` should refer to some kind of logical grouping inside of +the project. In smaller projects or when the scope is very large, it +can be omitted. + +Please take a look at the existing commit log for examples. + +## Commit content + +Multiple changes should be divided into multiple git commits whenever +possible. Common sense applies. + +The fix for a single-line whitespace issue is fine to include in a +different commit. Introducing a new feature and refactoring +(unrelated) code in the same commit is not fine. + +`git commit -a` is generally **taboo**. + +In my experience making "sane" commits becomes *significantly* easier +as developer tooling is improved. The interface to `git` that I +recommend is [magit][]. Even if you are not yet an Emacs user, it +makes sense to install Emacs just to be able to use magit - it is +really that good. + +For staging sane chunks on the command line with only git, consider +`git add -p`. + +## Code quality + +This one should go without saying - but please ensure that your code +quality does not fall below the rest of the project. This is of course +very subjective, but as an example if you place code that throws away +errors into a block in which errors are handled properly your change +will be rejected. + +In my experience there is a strong correlation between the visual +appearance of a code block and its quality. This is a simple way to +sanity-check your work while squinting and keeping some distance from +your screen ;-) + +## Builds & tests + +Most of my projects are built using [Nix][] to avoid "build pollution" +via the user's environment. If you have Nix installed and are +contributing to a project that has a `default.nix`, consider using +`nix-build` to verify that builds work correctly. + +If the project has tests, check that they still work before submitting +your change. + +Both of these will usually be covered by Travis CI. + + +[Angular project]: https://gist.github.com/stephenparish/9941e89d80e2bc58a153#format-of-the-commit-message +[magit]: https://magit.vc/ +[Nix]: https://nixos.org/nix/ -- cgit 1.4.1 From 565a00254b94c61e21ca7814324861bbfe5bde5d Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Thu, 29 Aug 2019 13:06:12 +0100 Subject: fix: Bump Nix in CI setup to 2.2.2 Yants does not seem to work with older versions of Nix and I have not yet figured out why. --- .travis.yml | 1 + 1 file changed, 1 insertion(+) diff --git a/.travis.yml b/.travis.yml index 0d998d034f..f38ce14fe3 100644 --- a/.travis.yml +++ b/.travis.yml @@ -1,3 +1,4 @@ language: nix +nix: 2.2.2 script: - nix eval --raw '(import ./tests.nix)' --show-trace -- cgit 1.4.1 From afd2fd5058d14c99ca60e9be28ee778f5df1958d Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 14 Sep 2019 13:07:21 +0100 Subject: docs(README): Add usage information to README This fixes #2. --- README.md | 48 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 46 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 383ae1788b..54e3e4a6a4 100644 --- a/README.md +++ b/README.md @@ -5,7 +5,7 @@ yants This is a tiny type-checker for data in Nix, written in Nix. -Features: +# Features * Checking of primitive types (`int`, `string` etc.) * Checking polymorphic types (`option`, `list`, `either`) @@ -16,7 +16,7 @@ Features: * Types are composable! `option string`! `list (either int (option float))`! * Type errors also compose! -Lacking: +Currently lacking: * Any kind of inference * Convenient syntax for attribute-set function signatures @@ -40,3 +40,47 @@ Lacking: ## Functions! ![functions](screenshots/functions.png) + +# Usage + +Yants can be imported from its `default.nix`. A single attribute (`lib`) can be +passed, which will otherwise be imported from ``. + +Examples for the most common import methods would be: + +1. Import into scope with `with`: + ```nix + with (import ./default.nix {}); + # ... Nix code that uses yants ... + ``` + +2. Import as a named variable: + ```nix + let yants = import ./default.nix {}; + in yants.string "foo" # or other uses ... + ```` + +3. Overlay into `pkgs.lib`: + ```nix + # wherever you import your package set (e.g. from ): + import { + overlays = [ + (self: super: { + lib = super.lib // { yants = import ./default.nix { inherit (super) lib; }; }; + }) + ]; + } + + # yants now lives at lib.yants, besides the other library functions! + ``` + +Please see my [Nix one-pager](https://github.com/tazjin/nix-1p) for more generic +information about the Nix language and what the above constructs mean. + +# Stability + +The current API of Yants is **not yet** considered stable, but it works fine and +should continue to do so even if used at an older version. + +Yants' tests use Nix versions above 2.2 - compatibility with older versions is +not guaranteed. -- cgit 1.4.1 From 7b1e389c664bca731be8ba66730be946a904d84c Mon Sep 17 00:00:00 2001 From: Michael Fellinger Date: Mon, 16 Sep 2019 12:27:54 +0200 Subject: Add path type --- default.nix | 1 + tests.nix | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/default.nix b/default.nix index 17564b61b9..9cd09e6440 100644 --- a/default.nix +++ b/default.nix @@ -97,6 +97,7 @@ in lib.fix (self: { bool = typedef "bool" isBool; float = typedef "float" isFloat; string = typedef "string" isString; + path = typedef "path" (x: typeOf x == "path"); drv = typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation"); function = typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" && isFunction x.__functor)); diff --git a/tests.nix b/tests.nix index 344f2c1f59..f2380a7709 100644 --- a/tests.nix +++ b/tests.nix @@ -12,6 +12,7 @@ deepSeq rec { (float 13.37) (string "Hello!") (function (x: x * 2)) + (path /nix) ]; # Test that polymorphic types work as intended @@ -76,7 +77,7 @@ deepSeq rec { # Test that all types are types. testTypes = map type [ - any bool drv float int string + any bool drv float int string path (attrs int) (either int string) -- cgit 1.4.1 From 13cc0d3d4814b4871b0e03fc0a522c135f3607e6 Mon Sep 17 00:00:00 2001 From: Alex Rice Date: Thu, 19 Sep 2019 15:33:07 +0100 Subject: feat: add n-ary either --- default.nix | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/default.nix b/default.nix index 9cd09e6440..2167b6e8b7 100644 --- a/default.nix +++ b/default.nix @@ -123,8 +123,10 @@ in lib.fix (self: { }; }; - either = t1: t2: typedef "either<${t1.name},${t2.name}>" - (x: (self.type t1).check x || (self.type t2).check x); + eitherN = tn: typedef "either<${concatStringsSep ", " (map (x: x.name) tn)}>" + (x: any (t: (self.type t).check x) tn); + + either = t1: t2: self.eitherN [ t1 t2 ]; list = t: typedef' rec { name = "list<${t.name}>"; -- cgit 1.4.1 From 5f6b51cce4feb91ac5748099811c1a70c30b2937 Mon Sep 17 00:00:00 2001 From: Alex Rice Date: Thu, 19 Sep 2019 15:35:05 +0100 Subject: test: add eitherN test --- tests.nix | 1 + 1 file changed, 1 insertion(+) diff --git a/tests.nix b/tests.nix index f2380a7709..6863ced066 100644 --- a/tests.nix +++ b/tests.nix @@ -80,6 +80,7 @@ deepSeq rec { any bool drv float int string path (attrs int) + (eitherN [ int string bool ]) (either int string) (enum [ "foo" "bar" ]) (list string) -- cgit 1.4.1 From 210893ce090d251df1b75082035deb60a9b06be5 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Fri, 20 Dec 2019 21:46:59 +0000 Subject: chore(yants): Prepare for depot-merge Yants is being integrated at //depot/nix/yants --- .travis.yml | 4 - CODE_OF_CONDUCT.md | 20 --- CONTRIBUTING.md | 115 ------------ LICENSE | 202 --------------------- README.md | 86 --------- default.nix | 298 ------------------------------- nix/yants/.skip-subtree | 1 + nix/yants/README.md | 86 +++++++++ nix/yants/default.nix | 298 +++++++++++++++++++++++++++++++ nix/yants/screenshots/enums.png | Bin 0 -> 41305 bytes nix/yants/screenshots/functions.png | Bin 0 -> 32907 bytes nix/yants/screenshots/nested-structs.png | Bin 0 -> 70264 bytes nix/yants/screenshots/simple.png | Bin 0 -> 43010 bytes nix/yants/screenshots/structs.png | Bin 0 -> 69499 bytes nix/yants/tests.nix | 92 ++++++++++ screenshots/enums.png | Bin 41305 -> 0 bytes screenshots/functions.png | Bin 32907 -> 0 bytes screenshots/nested-structs.png | Bin 70264 -> 0 bytes screenshots/simple.png | Bin 43010 -> 0 bytes screenshots/structs.png | Bin 69499 -> 0 bytes tests.nix | 92 ---------- 21 files changed, 477 insertions(+), 817 deletions(-) delete mode 100644 .travis.yml delete mode 100644 CODE_OF_CONDUCT.md delete mode 100644 CONTRIBUTING.md delete mode 100644 LICENSE delete mode 100644 README.md delete mode 100644 default.nix create mode 100644 nix/yants/.skip-subtree create mode 100644 nix/yants/README.md create mode 100644 nix/yants/default.nix create mode 100644 nix/yants/screenshots/enums.png create mode 100644 nix/yants/screenshots/functions.png create mode 100644 nix/yants/screenshots/nested-structs.png create mode 100644 nix/yants/screenshots/simple.png create mode 100644 nix/yants/screenshots/structs.png create mode 100644 nix/yants/tests.nix delete mode 100644 screenshots/enums.png delete mode 100644 screenshots/functions.png delete mode 100644 screenshots/nested-structs.png delete mode 100644 screenshots/simple.png delete mode 100644 screenshots/structs.png delete mode 100644 tests.nix diff --git a/.travis.yml b/.travis.yml deleted file mode 100644 index f38ce14fe3..0000000000 --- a/.travis.yml +++ /dev/null @@ -1,4 +0,0 @@ -language: nix -nix: 2.2.2 -script: - - nix eval --raw '(import ./tests.nix)' --show-trace diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md deleted file mode 100644 index c4013ac13e..0000000000 --- a/CODE_OF_CONDUCT.md +++ /dev/null @@ -1,20 +0,0 @@ -A SERMON ON ETHICS AND LOVE -=========================== - -One day Mal-2 asked the messenger spirit Saint Gulik to approach the Goddess and request Her presence for some desperate advice. Shortly afterwards the radio came on by itself, and an ethereal female Voice said **YES?** - -"O! Eris! Blessed Mother of Man! Queen of Chaos! Daughter of Discord! Concubine of Confusion! O! Exquisite Lady, I beseech You to lift a heavy burden from my heart!" - -**WHAT BOTHERS YOU, MAL? YOU DON'T SOUND WELL.** - -"I am filled with fear and tormented with terrible visions of pain. Everywhere people are hurting one another, the planet is rampant with injustices, whole societies plunder groups of their own people, mothers imprison sons, children perish while brothers war. O, woe." - -**WHAT IS THE MATTER WITH THAT, IF IT IS WHAT YOU WANT TO DO?** - -"But nobody Wants it! Everybody hates it." - -**OH. WELL, THEN *STOP*.** - -At which moment She turned herself into an aspirin commercial and left The Polyfather stranded alone with his species. - -SINISTER DEXTER HAS A BROKEN SPIROMETER. diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md deleted file mode 100644 index fb5f8210dd..0000000000 --- a/CONTRIBUTING.md +++ /dev/null @@ -1,115 +0,0 @@ -Contribution Guidelines -======================= - - -**Table of Contents** - -- [Contribution Guidelines](#contribution-guidelines) - - [Before making a change](#before-making-a-change) - - [Commit messages](#commit-messages) - - [Commit content](#commit-content) - - [Code quality](#code-quality) - - [Builds & tests](#builds--tests) - - - -This is a loose set of "guidelines" for contributing to my projects. -Please note that I will not accept any pull requests that don't follow -these guidelines. - -Also consider the [code of conduct](CODE_OF_CONDUCT.md). No really, -you should. - -## Before making a change - -Before making a change, consider your motivation for making the -change. Documentation updates, bug fixes and the like are *always* -welcome. - -When adding a feature you should consider whether it is only useful -for your particular use-case or whether it is generally applicable for -other users of the project. - -When in doubt - just ask me! - -## Commit messages - -All commit messages should follow the style-guide used by the [Angular -project][]. This means for the most part that your commit message -should be structured like this: - -``` -type(scope): Subject line with at most 68 a character length - -Body of the commit message with an empty line between subject and -body. This text should explain what the change does and why it has -been made, *especially* if it introduces a new feature. - -Relevant issues should be mentioned if they exist. -``` - -Where `type` can be one of: - -* `feat`: A new feature has been introduced -* `fix`: An issue of some kind has been fixed -* `docs`: Documentation or comments have been updated -* `style`: Formatting changes only -* `refactor`: Hopefully self-explanatory! -* `test`: Added missing tests / fixed tests -* `chore`: Maintenance work - -And `scope` should refer to some kind of logical grouping inside of -the project. In smaller projects or when the scope is very large, it -can be omitted. - -Please take a look at the existing commit log for examples. - -## Commit content - -Multiple changes should be divided into multiple git commits whenever -possible. Common sense applies. - -The fix for a single-line whitespace issue is fine to include in a -different commit. Introducing a new feature and refactoring -(unrelated) code in the same commit is not fine. - -`git commit -a` is generally **taboo**. - -In my experience making "sane" commits becomes *significantly* easier -as developer tooling is improved. The interface to `git` that I -recommend is [magit][]. Even if you are not yet an Emacs user, it -makes sense to install Emacs just to be able to use magit - it is -really that good. - -For staging sane chunks on the command line with only git, consider -`git add -p`. - -## Code quality - -This one should go without saying - but please ensure that your code -quality does not fall below the rest of the project. This is of course -very subjective, but as an example if you place code that throws away -errors into a block in which errors are handled properly your change -will be rejected. - -In my experience there is a strong correlation between the visual -appearance of a code block and its quality. This is a simple way to -sanity-check your work while squinting and keeping some distance from -your screen ;-) - -## Builds & tests - -Most of my projects are built using [Nix][] to avoid "build pollution" -via the user's environment. If you have Nix installed and are -contributing to a project that has a `default.nix`, consider using -`nix-build` to verify that builds work correctly. - -If the project has tests, check that they still work before submitting -your change. - -Both of these will usually be covered by Travis CI. - - -[Angular project]: https://gist.github.com/stephenparish/9941e89d80e2bc58a153#format-of-the-commit-message -[magit]: https://magit.vc/ -[Nix]: https://nixos.org/nix/ diff --git a/LICENSE b/LICENSE deleted file mode 100644 index d645695673..0000000000 --- a/LICENSE +++ /dev/null @@ -1,202 +0,0 @@ - - Apache License - Version 2.0, January 2004 - http://www.apache.org/licenses/ - - TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION - - 1. 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However, in accepting such obligations, You may act only - on Your own behalf and on Your sole responsibility, not on behalf - of any other Contributor, and only if You agree to indemnify, - defend, and hold each Contributor harmless for any liability - incurred by, or claims asserted against, such Contributor by reason - of your accepting any such warranty or additional liability. - - END OF TERMS AND CONDITIONS - - APPENDIX: How to apply the Apache License to your work. - - To apply the Apache License to your work, attach the following - boilerplate notice, with the fields enclosed by brackets "[]" - replaced with your own identifying information. (Don't include - the brackets!) The text should be enclosed in the appropriate - comment syntax for the file format. We also recommend that a - file or class name and description of purpose be included on the - same "printed page" as the copyright notice for easier - identification within third-party archives. - - Copyright [yyyy] [name of copyright owner] - - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. diff --git a/README.md b/README.md deleted file mode 100644 index 54e3e4a6a4..0000000000 --- a/README.md +++ /dev/null @@ -1,86 +0,0 @@ -yants -===== - -[![Build Status](https://travis-ci.org/tazjin/yants.svg?branch=master)](https://travis-ci.org/tazjin/yants) - -This is a tiny type-checker for data in Nix, written in Nix. - -# Features - -* Checking of primitive types (`int`, `string` etc.) -* Checking polymorphic types (`option`, `list`, `either`) -* Defining & checking struct/record types -* Defining & matching enum types -* Defining & matching sum types -* Defining function signatures (including curried functions) -* Types are composable! `option string`! `list (either int (option float))`! -* Type errors also compose! - -Currently lacking: - -* Any kind of inference -* Convenient syntax for attribute-set function signatures - -## Primitives & simple polymorphism - -![simple](screenshots/simple.png) - -## Structs - -![structs](screenshots/structs.png) - -## Nested structs! - -![nested structs](screenshots/nested-structs.png) - -## Enums! - -![enums](screenshots/enums.png) - -## Functions! - -![functions](screenshots/functions.png) - -# Usage - -Yants can be imported from its `default.nix`. A single attribute (`lib`) can be -passed, which will otherwise be imported from ``. - -Examples for the most common import methods would be: - -1. Import into scope with `with`: - ```nix - with (import ./default.nix {}); - # ... Nix code that uses yants ... - ``` - -2. Import as a named variable: - ```nix - let yants = import ./default.nix {}; - in yants.string "foo" # or other uses ... - ```` - -3. Overlay into `pkgs.lib`: - ```nix - # wherever you import your package set (e.g. from ): - import { - overlays = [ - (self: super: { - lib = super.lib // { yants = import ./default.nix { inherit (super) lib; }; }; - }) - ]; - } - - # yants now lives at lib.yants, besides the other library functions! - ``` - -Please see my [Nix one-pager](https://github.com/tazjin/nix-1p) for more generic -information about the Nix language and what the above constructs mean. - -# Stability - -The current API of Yants is **not yet** considered stable, but it works fine and -should continue to do so even if used at an older version. - -Yants' tests use Nix versions above 2.2 - compatibility with older versions is -not guaranteed. diff --git a/default.nix b/default.nix deleted file mode 100644 index 2167b6e8b7..0000000000 --- a/default.nix +++ /dev/null @@ -1,298 +0,0 @@ -# Copyright 2019 Google LLC -# SPDX-License-Identifier: Apache-2.0 -# -# Provides a "type-system" for Nix that provides various primitive & -# polymorphic types as well as the ability to define & check records. -# -# All types (should) compose as expected. - -{ lib ? (import {}).lib }: - -with builtins; let - prettyPrint = lib.generators.toPretty {}; - - # typedef' :: struct { - # name = string; - # checkType = function; (a -> result) - # checkToBool = option function; (result -> bool) - # toError = option function; (a -> result -> string) - # def = option any; - # match = option function; - # } -> type - # -> (a -> b) - # -> (b -> bool) - # -> (a -> b -> string) - # -> type - # - # This function creates an attribute set that acts as a type. - # - # It receives a type name, a function that is used to perform a - # check on an arbitrary value, a function that can translate the - # return of that check to a boolean that informs whether the value - # is type-conformant, and a function that can construct error - # messages from the check result. - # - # This function is the low-level primitive used to create types. For - # many cases the higher-level 'typedef' function is more appropriate. - typedef' = { name, checkType - , checkToBool ? (result: result.ok) - , toError ? (_: result: result.err) - , def ? null - , match ? null }: { - inherit name checkToBool toError; - - # check :: a -> bool - # - # This function is used to determine whether a given type is - # conformant. - check = value: checkToBool (checkType value); - - # checkType :: a -> struct { ok = bool; err = option string; } - # - # This function checks whether the passed value is type conformant - # and returns an optional type error string otherwise. - inherit checkType; - - # __functor :: a -> a - # - # This function checks whether the passed value is type conformant - # and throws an error if it is not. - # - # The name of this function is a special attribute in Nix that - # makes it possible to execute a type attribute set like a normal - # function. - __functor = self: value: - let result = self.checkType value; - in if checkToBool result then value - else throw (toError value result); - }; - - typeError = type: val: - "expected type '${type}', but value '${prettyPrint val}' is of type '${typeOf val}'"; - - # typedef :: string -> (a -> bool) -> type - # - # typedef is the simplified version of typedef' which uses a default - # error message constructor. - typedef = name: check: typedef' { - inherit name; - checkType = check; - checkToBool = r: r; - toError = value: _result: typeError name value; - }; - - checkEach = name: t: l: foldl' (acc: e: - let res = t.checkType e; - isT = t.checkToBool res; - in { - ok = acc.ok && isT; - err = if isT - then acc.err - else acc.err + "${prettyPrint e}: ${t.toError e res}\n"; - }) { ok = true; err = "expected type ${name}, but found:\n"; } l; -in lib.fix (self: { - # Primitive types - any = typedef "any" (_: true); - int = typedef "int" isInt; - bool = typedef "bool" isBool; - float = typedef "float" isFloat; - string = typedef "string" isString; - path = typedef "path" (x: typeOf x == "path"); - drv = typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation"); - function = typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" - && isFunction x.__functor)); - - # Type for types themselves. Useful when defining polymorphic types. - type = typedef "type" (x: - isAttrs x - && hasAttr "name" x && self.string.check x.name - && hasAttr "checkType" x && self.function.check x.checkType - && hasAttr "checkToBool" x && self.function.check x.checkToBool - && hasAttr "toError" x && self.function.check x.toError - ); - - # Polymorphic types - option = t: typedef' rec { - name = "option<${t.name}>"; - checkType = v: - let res = t.checkType v; - in { - ok = isNull v || (self.type t).checkToBool res; - err = "expected type ${name}, but value does not conform to '${t.name}': " - + t.toError v res; - }; - }; - - eitherN = tn: typedef "either<${concatStringsSep ", " (map (x: x.name) tn)}>" - (x: any (t: (self.type t).check x) tn); - - either = t1: t2: self.eitherN [ t1 t2 ]; - - list = t: typedef' rec { - name = "list<${t.name}>"; - - checkType = v: if isList v - then checkEach name (self.type t) v - else { - ok = false; - err = typeError name v; - }; - }; - - attrs = t: typedef' rec { - name = "attrs<${t.name}>"; - - checkType = v: if isAttrs v - then checkEach name (self.type t) (attrValues v) - else { - ok = false; - err = typeError name v; - }; - }; - - # Structs / record types - # - # Checks that all fields match their declared types, no optional - # fields are missing and no unexpected fields occur in the struct. - # - # Anonymous structs are supported (e.g. for nesting) by omitting the - # name. - # - # TODO: Support open records? - struct = - # Struct checking is more involved than the simpler types above. - # To make the actual type definition more readable, several - # helpers are defined below. - let - # checkField checks an individual field of the struct against - # its definition and creates a typecheck result. These results - # are aggregated during the actual checking. - checkField = def: name: value: let result = def.checkType value; in rec { - ok = def.checkToBool result; - err = if !ok && isNull value - then "missing required ${def.name} field '${name}'\n" - else "field '${name}': ${def.toError value result}\n"; - }; - - # checkExtraneous determines whether a (closed) struct contains - # any fields that are not part of the definition. - checkExtraneous = def: has: acc: - if (length has) == 0 then acc - else if (hasAttr (head has) def) - then checkExtraneous def (tail has) acc - else checkExtraneous def (tail has) { - ok = false; - err = acc.err + "unexpected struct field '${head has}'\n"; - }; - - # checkStruct combines all structure checks and creates one - # typecheck result from them - checkStruct = def: value: - let - init = { ok = true; err = ""; }; - extraneous = checkExtraneous def (attrNames value) init; - - checkedFields = map (n: - let v = if hasAttr n value then value."${n}" else null; - in checkField def."${n}" n v) (attrNames def); - - combined = foldl' (acc: res: { - ok = acc.ok && res.ok; - err = if !res.ok then acc.err + res.err else acc.err; - }) init checkedFields; - in { - ok = combined.ok && extraneous.ok; - err = combined.err + extraneous.err; - }; - - struct' = name: def: typedef' { - inherit name def; - checkType = value: if isAttrs value - then (checkStruct (self.attrs self.type def) value) - else { ok = false; err = typeError name value; }; - - toError = _: result: "expected '${name}'-struct, but found:\n" + result.err; - }; - in arg: if isString arg then (struct' arg) else (struct' "anon" arg); - - # Enums & pattern matching - enum = - let - plain = name: def: typedef' { - inherit name def; - - checkType = (x: isString x && elem x def); - checkToBool = x: x; - toError = value: _: "'${prettyPrint value} is not a member of enum ${name}"; - }; - enum' = name: def: lib.fix (e: (plain name def) // { - match = x: actions: deepSeq (map e (attrNames actions)) ( - let - actionKeys = attrNames actions; - missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] def; - in if (length missing) > 0 - then throw "Missing match action for members: ${prettyPrint missing}" - else actions."${e x}"); - }); - in arg: if isString arg then (enum' arg) else (enum' "anon" arg); - - # Sum types - # - # The representation of a sum type is an attribute set with only one - # value, where the key of the value denotes the variant of the type. - sum = - let - plain = name: def: typedef' { - inherit name def; - checkType = (x: - let variant = elemAt (attrNames x) 0; - in if isAttrs x && length (attrNames x) == 1 && hasAttr variant def - then let t = def."${variant}"; - v = x."${variant}"; - res = t.checkType v; - in if t.checkToBool res - then { ok = true; } - else { - ok = false; - err = "while checking '${name}' variant '${variant}': " - + t.toError v res; - } - else { ok = false; err = typeError name x; } - ); - }; - sum' = name: def: lib.fix (s: (plain name def) // { - match = x: actions: - let variant = deepSeq (s x) (elemAt (attrNames x) 0); - actionKeys = attrNames actions; - defKeys = attrNames def; - missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] defKeys; - in if (length missing) > 0 - then throw "Missing match action for variants: ${prettyPrint missing}" - else actions."${variant}" x."${variant}"; - }); - in arg: if isString arg then (sum' arg) else (sum' "anon" arg); - - # Typed function definitions - # - # These definitions wrap the supplied function in type-checking - # forms that are evaluated when the function is called. - # - # Note that typed functions themselves are not types and can not be - # used to check values for conformity. - defun = - let - mkFunc = sig: f: { - inherit sig; - __toString = self: foldl' (s: t: "${s} -> ${t.name}") - "λ :: ${(head self.sig).name}" (tail self.sig); - __functor = _: f; - }; - - defun' = sig: func: if length sig > 2 - then mkFunc sig (x: defun' (tail sig) (func ((head sig) x))) - else mkFunc sig (x: ((head (tail sig)) (func ((head sig) x)))); - - in sig: func: if length sig < 2 - then (throw "Signature must at least have two types (a -> b)") - else defun' sig func; -}) diff --git a/nix/yants/.skip-subtree b/nix/yants/.skip-subtree new file mode 100644 index 0000000000..51a8e01d4e --- /dev/null +++ b/nix/yants/.skip-subtree @@ -0,0 +1 @@ +Yants subtree contains no further derivations. diff --git a/nix/yants/README.md b/nix/yants/README.md new file mode 100644 index 0000000000..54e3e4a6a4 --- /dev/null +++ b/nix/yants/README.md @@ -0,0 +1,86 @@ +yants +===== + +[![Build Status](https://travis-ci.org/tazjin/yants.svg?branch=master)](https://travis-ci.org/tazjin/yants) + +This is a tiny type-checker for data in Nix, written in Nix. + +# Features + +* Checking of primitive types (`int`, `string` etc.) +* Checking polymorphic types (`option`, `list`, `either`) +* Defining & checking struct/record types +* Defining & matching enum types +* Defining & matching sum types +* Defining function signatures (including curried functions) +* Types are composable! `option string`! `list (either int (option float))`! +* Type errors also compose! + +Currently lacking: + +* Any kind of inference +* Convenient syntax for attribute-set function signatures + +## Primitives & simple polymorphism + +![simple](screenshots/simple.png) + +## Structs + +![structs](screenshots/structs.png) + +## Nested structs! + +![nested structs](screenshots/nested-structs.png) + +## Enums! + +![enums](screenshots/enums.png) + +## Functions! + +![functions](screenshots/functions.png) + +# Usage + +Yants can be imported from its `default.nix`. A single attribute (`lib`) can be +passed, which will otherwise be imported from ``. + +Examples for the most common import methods would be: + +1. Import into scope with `with`: + ```nix + with (import ./default.nix {}); + # ... Nix code that uses yants ... + ``` + +2. Import as a named variable: + ```nix + let yants = import ./default.nix {}; + in yants.string "foo" # or other uses ... + ```` + +3. Overlay into `pkgs.lib`: + ```nix + # wherever you import your package set (e.g. from ): + import { + overlays = [ + (self: super: { + lib = super.lib // { yants = import ./default.nix { inherit (super) lib; }; }; + }) + ]; + } + + # yants now lives at lib.yants, besides the other library functions! + ``` + +Please see my [Nix one-pager](https://github.com/tazjin/nix-1p) for more generic +information about the Nix language and what the above constructs mean. + +# Stability + +The current API of Yants is **not yet** considered stable, but it works fine and +should continue to do so even if used at an older version. + +Yants' tests use Nix versions above 2.2 - compatibility with older versions is +not guaranteed. diff --git a/nix/yants/default.nix b/nix/yants/default.nix new file mode 100644 index 0000000000..2167b6e8b7 --- /dev/null +++ b/nix/yants/default.nix @@ -0,0 +1,298 @@ +# Copyright 2019 Google LLC +# SPDX-License-Identifier: Apache-2.0 +# +# Provides a "type-system" for Nix that provides various primitive & +# polymorphic types as well as the ability to define & check records. +# +# All types (should) compose as expected. + +{ lib ? (import {}).lib }: + +with builtins; let + prettyPrint = lib.generators.toPretty {}; + + # typedef' :: struct { + # name = string; + # checkType = function; (a -> result) + # checkToBool = option function; (result -> bool) + # toError = option function; (a -> result -> string) + # def = option any; + # match = option function; + # } -> type + # -> (a -> b) + # -> (b -> bool) + # -> (a -> b -> string) + # -> type + # + # This function creates an attribute set that acts as a type. + # + # It receives a type name, a function that is used to perform a + # check on an arbitrary value, a function that can translate the + # return of that check to a boolean that informs whether the value + # is type-conformant, and a function that can construct error + # messages from the check result. + # + # This function is the low-level primitive used to create types. For + # many cases the higher-level 'typedef' function is more appropriate. + typedef' = { name, checkType + , checkToBool ? (result: result.ok) + , toError ? (_: result: result.err) + , def ? null + , match ? null }: { + inherit name checkToBool toError; + + # check :: a -> bool + # + # This function is used to determine whether a given type is + # conformant. + check = value: checkToBool (checkType value); + + # checkType :: a -> struct { ok = bool; err = option string; } + # + # This function checks whether the passed value is type conformant + # and returns an optional type error string otherwise. + inherit checkType; + + # __functor :: a -> a + # + # This function checks whether the passed value is type conformant + # and throws an error if it is not. + # + # The name of this function is a special attribute in Nix that + # makes it possible to execute a type attribute set like a normal + # function. + __functor = self: value: + let result = self.checkType value; + in if checkToBool result then value + else throw (toError value result); + }; + + typeError = type: val: + "expected type '${type}', but value '${prettyPrint val}' is of type '${typeOf val}'"; + + # typedef :: string -> (a -> bool) -> type + # + # typedef is the simplified version of typedef' which uses a default + # error message constructor. + typedef = name: check: typedef' { + inherit name; + checkType = check; + checkToBool = r: r; + toError = value: _result: typeError name value; + }; + + checkEach = name: t: l: foldl' (acc: e: + let res = t.checkType e; + isT = t.checkToBool res; + in { + ok = acc.ok && isT; + err = if isT + then acc.err + else acc.err + "${prettyPrint e}: ${t.toError e res}\n"; + }) { ok = true; err = "expected type ${name}, but found:\n"; } l; +in lib.fix (self: { + # Primitive types + any = typedef "any" (_: true); + int = typedef "int" isInt; + bool = typedef "bool" isBool; + float = typedef "float" isFloat; + string = typedef "string" isString; + path = typedef "path" (x: typeOf x == "path"); + drv = typedef "derivation" (x: isAttrs x && x ? "type" && x.type == "derivation"); + function = typedef "function" (x: isFunction x || (isAttrs x && x ? "__functor" + && isFunction x.__functor)); + + # Type for types themselves. Useful when defining polymorphic types. + type = typedef "type" (x: + isAttrs x + && hasAttr "name" x && self.string.check x.name + && hasAttr "checkType" x && self.function.check x.checkType + && hasAttr "checkToBool" x && self.function.check x.checkToBool + && hasAttr "toError" x && self.function.check x.toError + ); + + # Polymorphic types + option = t: typedef' rec { + name = "option<${t.name}>"; + checkType = v: + let res = t.checkType v; + in { + ok = isNull v || (self.type t).checkToBool res; + err = "expected type ${name}, but value does not conform to '${t.name}': " + + t.toError v res; + }; + }; + + eitherN = tn: typedef "either<${concatStringsSep ", " (map (x: x.name) tn)}>" + (x: any (t: (self.type t).check x) tn); + + either = t1: t2: self.eitherN [ t1 t2 ]; + + list = t: typedef' rec { + name = "list<${t.name}>"; + + checkType = v: if isList v + then checkEach name (self.type t) v + else { + ok = false; + err = typeError name v; + }; + }; + + attrs = t: typedef' rec { + name = "attrs<${t.name}>"; + + checkType = v: if isAttrs v + then checkEach name (self.type t) (attrValues v) + else { + ok = false; + err = typeError name v; + }; + }; + + # Structs / record types + # + # Checks that all fields match their declared types, no optional + # fields are missing and no unexpected fields occur in the struct. + # + # Anonymous structs are supported (e.g. for nesting) by omitting the + # name. + # + # TODO: Support open records? + struct = + # Struct checking is more involved than the simpler types above. + # To make the actual type definition more readable, several + # helpers are defined below. + let + # checkField checks an individual field of the struct against + # its definition and creates a typecheck result. These results + # are aggregated during the actual checking. + checkField = def: name: value: let result = def.checkType value; in rec { + ok = def.checkToBool result; + err = if !ok && isNull value + then "missing required ${def.name} field '${name}'\n" + else "field '${name}': ${def.toError value result}\n"; + }; + + # checkExtraneous determines whether a (closed) struct contains + # any fields that are not part of the definition. + checkExtraneous = def: has: acc: + if (length has) == 0 then acc + else if (hasAttr (head has) def) + then checkExtraneous def (tail has) acc + else checkExtraneous def (tail has) { + ok = false; + err = acc.err + "unexpected struct field '${head has}'\n"; + }; + + # checkStruct combines all structure checks and creates one + # typecheck result from them + checkStruct = def: value: + let + init = { ok = true; err = ""; }; + extraneous = checkExtraneous def (attrNames value) init; + + checkedFields = map (n: + let v = if hasAttr n value then value."${n}" else null; + in checkField def."${n}" n v) (attrNames def); + + combined = foldl' (acc: res: { + ok = acc.ok && res.ok; + err = if !res.ok then acc.err + res.err else acc.err; + }) init checkedFields; + in { + ok = combined.ok && extraneous.ok; + err = combined.err + extraneous.err; + }; + + struct' = name: def: typedef' { + inherit name def; + checkType = value: if isAttrs value + then (checkStruct (self.attrs self.type def) value) + else { ok = false; err = typeError name value; }; + + toError = _: result: "expected '${name}'-struct, but found:\n" + result.err; + }; + in arg: if isString arg then (struct' arg) else (struct' "anon" arg); + + # Enums & pattern matching + enum = + let + plain = name: def: typedef' { + inherit name def; + + checkType = (x: isString x && elem x def); + checkToBool = x: x; + toError = value: _: "'${prettyPrint value} is not a member of enum ${name}"; + }; + enum' = name: def: lib.fix (e: (plain name def) // { + match = x: actions: deepSeq (map e (attrNames actions)) ( + let + actionKeys = attrNames actions; + missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] def; + in if (length missing) > 0 + then throw "Missing match action for members: ${prettyPrint missing}" + else actions."${e x}"); + }); + in arg: if isString arg then (enum' arg) else (enum' "anon" arg); + + # Sum types + # + # The representation of a sum type is an attribute set with only one + # value, where the key of the value denotes the variant of the type. + sum = + let + plain = name: def: typedef' { + inherit name def; + checkType = (x: + let variant = elemAt (attrNames x) 0; + in if isAttrs x && length (attrNames x) == 1 && hasAttr variant def + then let t = def."${variant}"; + v = x."${variant}"; + res = t.checkType v; + in if t.checkToBool res + then { ok = true; } + else { + ok = false; + err = "while checking '${name}' variant '${variant}': " + + t.toError v res; + } + else { ok = false; err = typeError name x; } + ); + }; + sum' = name: def: lib.fix (s: (plain name def) // { + match = x: actions: + let variant = deepSeq (s x) (elemAt (attrNames x) 0); + actionKeys = attrNames actions; + defKeys = attrNames def; + missing = foldl' (m: k: if (elem k actionKeys) then m else m ++ [ k ]) [] defKeys; + in if (length missing) > 0 + then throw "Missing match action for variants: ${prettyPrint missing}" + else actions."${variant}" x."${variant}"; + }); + in arg: if isString arg then (sum' arg) else (sum' "anon" arg); + + # Typed function definitions + # + # These definitions wrap the supplied function in type-checking + # forms that are evaluated when the function is called. + # + # Note that typed functions themselves are not types and can not be + # used to check values for conformity. + defun = + let + mkFunc = sig: f: { + inherit sig; + __toString = self: foldl' (s: t: "${s} -> ${t.name}") + "λ :: ${(head self.sig).name}" (tail self.sig); + __functor = _: f; + }; + + defun' = sig: func: if length sig > 2 + then mkFunc sig (x: defun' (tail sig) (func ((head sig) x))) + else mkFunc sig (x: ((head (tail sig)) (func ((head sig) x)))); + + in sig: func: if length sig < 2 + then (throw "Signature must at least have two types (a -> b)") + else defun' sig func; +}) diff --git a/nix/yants/screenshots/enums.png b/nix/yants/screenshots/enums.png new file mode 100644 index 0000000000..71673e7ab6 Binary files /dev/null and b/nix/yants/screenshots/enums.png differ diff --git a/nix/yants/screenshots/functions.png b/nix/yants/screenshots/functions.png new file mode 100644 index 0000000000..30ed50f832 Binary files /dev/null and b/nix/yants/screenshots/functions.png differ diff --git a/nix/yants/screenshots/nested-structs.png b/nix/yants/screenshots/nested-structs.png new file mode 100644 index 0000000000..6b03ed65ce Binary files /dev/null and b/nix/yants/screenshots/nested-structs.png differ diff --git a/nix/yants/screenshots/simple.png b/nix/yants/screenshots/simple.png new file mode 100644 index 0000000000..05a302cc6b Binary files /dev/null and b/nix/yants/screenshots/simple.png differ diff --git a/nix/yants/screenshots/structs.png b/nix/yants/screenshots/structs.png new file mode 100644 index 0000000000..fcbcf6415f Binary files /dev/null and b/nix/yants/screenshots/structs.png differ diff --git a/nix/yants/tests.nix b/nix/yants/tests.nix new file mode 100644 index 0000000000..6863ced066 --- /dev/null +++ b/nix/yants/tests.nix @@ -0,0 +1,92 @@ +with builtins; +with (import ./default.nix {}); + +# Note: Derivations are not included in the tests below as they cause +# issues with deepSeq. + +deepSeq rec { + # Test that all primitive types match + primitives = [ + (int 15) + (bool false) + (float 13.37) + (string "Hello!") + (function (x: x * 2)) + (path /nix) + ]; + + # Test that polymorphic types work as intended + poly = [ + (option int null) + (list string [ "foo" "bar" ]) + (either int float 42) + ]; + + # Test that structures work as planned. + person = struct "person" { + name = string; + age = int; + + contact = option (struct { + email = string; + phone = option string; + }); + }; + + testPerson = person { + name = "Brynhjulf"; + age = 42; + contact.email = "brynhjulf@yants.nix"; + }; + + # Test enum definitions & matching + colour = enum "colour" [ "red" "blue" "green" ]; + testMatch = colour.match "red" { + red = "It is in fact red!"; + blue = throw "It should not be blue!"; + green = throw "It should not be green!"; + }; + + # Test sum type definitions + creature = sum "creature" { + human = struct { + name = string; + age = option int; + }; + + pet = enum "pet" [ "dog" "lizard" "cat" ]; + }; + + testSum = creature { + human = { + name = "Brynhjulf"; + age = 42; + }; + }; + + testSumMatch = creature.match testSum { + human = v: "It's a human named ${v.name}"; + pet = v: throw "It's not supposed to be a pet!"; + }; + + # Test curried function definitions + func = defun [ string int string ] + (name: age: "${name} is ${toString age} years old"); + + testFunc = func "Brynhjulf" 42; + + # Test that all types are types. + testTypes = map type [ + any bool drv float int string path + + (attrs int) + (eitherN [ int string bool ]) + (either int string) + (enum [ "foo" "bar" ]) + (list string) + (option int) + (option (list string)) + (struct { a = int; b = option string; }) + (sum { a = int; b = option string; }) + ]; +} "All tests passed!\n" diff --git a/screenshots/enums.png b/screenshots/enums.png deleted file mode 100644 index 71673e7ab6..0000000000 Binary files a/screenshots/enums.png and /dev/null differ diff --git a/screenshots/functions.png b/screenshots/functions.png deleted file mode 100644 index 30ed50f832..0000000000 Binary files a/screenshots/functions.png and /dev/null differ diff --git a/screenshots/nested-structs.png b/screenshots/nested-structs.png deleted file mode 100644 index 6b03ed65ce..0000000000 Binary files a/screenshots/nested-structs.png and /dev/null differ diff --git a/screenshots/simple.png b/screenshots/simple.png deleted file mode 100644 index 05a302cc6b..0000000000 Binary files a/screenshots/simple.png and /dev/null differ diff --git a/screenshots/structs.png b/screenshots/structs.png deleted file mode 100644 index fcbcf6415f..0000000000 Binary files a/screenshots/structs.png and /dev/null differ diff --git a/tests.nix b/tests.nix deleted file mode 100644 index 6863ced066..0000000000 --- a/tests.nix +++ /dev/null @@ -1,92 +0,0 @@ -with builtins; -with (import ./default.nix {}); - -# Note: Derivations are not included in the tests below as they cause -# issues with deepSeq. - -deepSeq rec { - # Test that all primitive types match - primitives = [ - (int 15) - (bool false) - (float 13.37) - (string "Hello!") - (function (x: x * 2)) - (path /nix) - ]; - - # Test that polymorphic types work as intended - poly = [ - (option int null) - (list string [ "foo" "bar" ]) - (either int float 42) - ]; - - # Test that structures work as planned. - person = struct "person" { - name = string; - age = int; - - contact = option (struct { - email = string; - phone = option string; - }); - }; - - testPerson = person { - name = "Brynhjulf"; - age = 42; - contact.email = "brynhjulf@yants.nix"; - }; - - # Test enum definitions & matching - colour = enum "colour" [ "red" "blue" "green" ]; - testMatch = colour.match "red" { - red = "It is in fact red!"; - blue = throw "It should not be blue!"; - green = throw "It should not be green!"; - }; - - # Test sum type definitions - creature = sum "creature" { - human = struct { - name = string; - age = option int; - }; - - pet = enum "pet" [ "dog" "lizard" "cat" ]; - }; - - testSum = creature { - human = { - name = "Brynhjulf"; - age = 42; - }; - }; - - testSumMatch = creature.match testSum { - human = v: "It's a human named ${v.name}"; - pet = v: throw "It's not supposed to be a pet!"; - }; - - # Test curried function definitions - func = defun [ string int string ] - (name: age: "${name} is ${toString age} years old"); - - testFunc = func "Brynhjulf" 42; - - # Test that all types are types. - testTypes = map type [ - any bool drv float int string path - - (attrs int) - (eitherN [ int string bool ]) - (either int string) - (enum [ "foo" "bar" ]) - (list string) - (option int) - (option (list string)) - (struct { a = int; b = option string; }) - (sum { a = int; b = option string; }) - ]; -} "All tests passed!\n" -- cgit 1.4.1