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2011-07-13 * Allow a default value in attribute selection by writingEelco Dolstra1-0/+2
x.y.z or default (as originally proposed in https://mail.cs.uu.nl/pipermail/nix-dev/2009-September/002989.html). For instance, an expression like stdenv.lib.attrByPath ["features" "ckSched"] false args can now be written as args.features.ckSched or false
2011-07-06 * Change the right-hand side of the ‘.’ operator from an attribute toEelco Dolstra1-1/+1
an attribute path. This is a refactoring to support default values.
2011-07-06 * In the ‘?’ operator, allow attribute paths. For instance, you canEelco Dolstra1-1/+12
write ‘attrs ? a.b’ to test whether ‘attrs’ has an attribute ‘a’ containing an attribute ‘b’. This is more convenient than ‘attrs ? a && attrs.a ? b’. Slight change in the semantics: it's no longer an error if the left-hand side of ‘?’ is not an attribute set. In that case it just returns false. So, ‘null ? foo’ no longer throws an error.
2010-10-24 * Keep attribute sets in sorted order to speed up attribute lookups.Eelco Dolstra1-37/+26
* Simplify the representation of attributes in the AST. * Change the behaviour of listToAttrs() in case of duplicate names.
2010-10-22 * Store Value nodes outside of attribute sets. I.e., Attr now storesEelco Dolstra1-2/+2
a pointer to a Value, rather than the Value directly. This improves the effectiveness of garbage collection a lot: if the Value is stored inside the set directly, then any live pointer to the Value causes all other attributes in the set to be live as well.
2010-05-07 * Store position info for inherited attributes.Eelco Dolstra1-12/+12
2010-05-06 * Store attribute positions in the AST and report duplicate attributeEelco Dolstra1-5/+8
errors with position info. * For all positions, use the position of the first character of the first token, rather than the last character of the first token plus one.
2010-04-22 * Simplify the implementation of `with'. This gives a 7% speedup inEelco Dolstra1-4/+4
evaluating the NixOS system configuration.
2010-04-14 * Implemented inherit.Eelco Dolstra1-9/+17
2010-04-14 * Refactoring: move variable uses to a separate class.Eelco Dolstra1-2/+7
2010-04-14 * Implemented withs.Eelco Dolstra1-0/+12
2010-04-14 * After parsing, compute level/displacement pairs for each variableEelco Dolstra1-79/+139
use site, allowing environments to be stores as vectors of values rather than maps. This should speed up evaluation and reduce the number of allocations.
2010-04-14 * Remove more obsolete code.Eelco Dolstra1-29/+0
2010-04-13 * Evaluate lets directly (i.e. without desugaring to `rec { attrs...;Eelco Dolstra1-0/+10
<let-body> = e; }.<let-body>). This prevents the unnecessary allocation of an attribute set.
2010-04-13 * Use a symbol table to represent identifiers and attribute namesEelco Dolstra1-3/+3
efficiently. The symbol table ensures that there is only one copy of each symbol, thus allowing symbols to be compared efficiently using a pointer equality test.
2010-04-12 * Finished the ATerm-less parser.Eelco Dolstra1-1/+1
2010-04-12 * Indented strings.Eelco Dolstra1-14/+5
2010-04-12 * More missing constructs.Eelco Dolstra1-8/+31
2010-04-12 * Don't use ATerms for the abstract syntax trees anymore. NotEelco Dolstra1-27/+83
finished yet.
2010-04-08 * Remove a lot of dead code.Eelco Dolstra1-217/+0
2010-03-25 * Simplify @-patterns: only `{attrs}@name' or `name@{attrs}' are nowEelco Dolstra1-6/+2
allowed. So `name1@name2', `{attrs1}@{attrs2}' and so on are now no longer legal. This is no big loss because they were not useful anyway. This also changes the output of builtins.toXML for @-patterns slightly.
2009-05-15 * Some syntactic sugar for attribute sets: allow {x.y.z = ...;} as aEelco Dolstra1-1/+1
shorthand for {x = {y = {z = ...;};};}. This is especially useful for NixOS configuration files, e.g. { services = { sshd = { enable = true; port = 2022; }; }; } can now be written as { services.sshd.enable = true; services.sshd.port = 2022; } However, it is currently not permitted to write { services.sshd = {enable = true;}; services.sshd.port = 2022; } as this is considered a duplicate definition of `services.sshd'.
2008-08-14 * Added an experimental feature suggested by Andres: ellipses ("...")Eelco Dolstra1-2/+3
in attribute set pattern matches. This allows defining a function that takes *at least* the listed attributes, while ignoring additional attributes. For instance, {stdenv, fetchurl, fuse, ...}: stdenv.mkDerivation { ... }; defines a function that requires an attribute set that contains the specified attributes but ignores others. The main advantage is that we can then write in all-packages.nix aefs = import ../bla/aefs pkgs; instead of aefs = import ../bla/aefs { inherit stdenv fetchurl fuse; }; This saves a lot of typing (not to mention not having to update all-packages.nix with purely mechanical changes). It saves as much typing as the "args: with args;" style, but has the advantage that the function arguments are properly declared (not implicit in what the body of the "with" uses).
2008-08-14 * @-patterns as in Haskell. For instance, in a function definitionEelco Dolstra1-1/+6
f = args @ {x, y, z}: ...; `args' refers to the argument as a whole, which is further pattern-matched against the attribute set pattern {x, y, z}.
2008-08-14 * Refactoring: combine functions that take an attribute set andEelco Dolstra1-37/+30
functions that take a single argument (plain lambdas) into one AST node (Function) that contains a Pattern node describing the arguments. Current patterns are single lazy arguments (VarPat) and matching against an attribute set (AttrsPat). This refactoring allows other kinds of patterns to be added easily, such as Haskell-style @-patterns, or list pattern matching.
2008-08-11 * Removed the "valid values" feature. Nobody uses it anyway.Eelco Dolstra1-7/+6
2008-05-21 * GCC 4.3.0 (Fedora 9) compatibility fixes. Reported by Gour andEelco Dolstra1-0/+2
Armijn Hemel.
2008-02-21 * checkVarDefs: don't check in closed terms, which don't haveEelco Dolstra1-1/+5
undefined variables by definition. This matters for the implementation of "with", which does a call to checkVarDefs to see if the body of the with has no undefined variables. (It can't be checked at parse time because you don't know which variables are in the "with" attribute set.) If we check closed terms, then we check not just the with body but also the substituted terms, which are typically very large. This is the cause of the poor nix-env performance on Nixpkgs lately. It didn't happen earlier because "with" wasn't used very often in the past. This fix improves nix-env performance roughly 60x on current Nixpkgs. nix-env -qa is down from 29.3s to 0.5s on my laptop, and nix-env -qa --out-path is down from 229s to 3.39s. Not bad for a 1-line fix :-)
2007-02-02 * nix-env now maintains meta info (from the `meta' derivationEelco Dolstra1-1/+1
attribute) about installed packages in user environments. Thus, an operation like `nix-env -q --description' shows useful information not only on available packages but also on installed packages. * nix-env now passes the entire manifest as an argument to the Nix expression of the user environment builder (not just a list of paths), so that in particular the user environment builder has access to the meta attributes. * New operation `--set-flag' in nix-env to change meta info of installed packages. This will be useful to pass per-package policies to the user environment builder (e.g., how to resolve collision or whether to disable a package (NIX-80)) or upgrade policies in nix-env (e.g., that a package should be "masked", that is, left untouched by upgrade actions). Example: $ nix-env --set-flag enabled false ghc-6.4
2007-01-13 * Canonicalise ASTs in `nix-instantiate --eval': remove positionEelco Dolstra1-0/+39
info, sort attribute sets.
2006-10-23 * Some better error messages.Eelco Dolstra1-2/+2
2006-10-16 * Big cleanup of the semantics of paths, strings, contexts, stringEelco Dolstra1-7/+30
concatenation and string coercion. This was a big mess (see e.g. NIX-67). Contexts are now folded into strings, so that they don't cause evaluation errors when they're not expected. The semantics of paths has been clarified (see nixexpr-ast.def). toString() and coerceToString() have been merged. Semantic change: paths are now copied to the store when they're in a concatenation (and in most other situations - that's the formalisation of the meaning of a path). So "foo " + ./bla evaluates to "foo /nix/store/hash...-bla", not "foo /path/to/current-dir/bla". This prevents accidental impurities, and is more consistent with the treatment of derivation outputs, e.g., `"foo " + bla' where `bla' is a derivation. (Here `bla' would be replaced by the output path of `bla'.)
2006-10-11 * Removed URIs from the evaluator (NIX-66). They are now just anotherEelco Dolstra1-2/+0
kind of notation for strings.
2006-10-03 * toFile: added an additional argument to specify the store pathEelco Dolstra1-0/+2
suffix, e.g., `builtins.toFile "builder.sh" "..."'. * toFile: handle references to other files correctly.
2006-09-05 * Sone missing #includes.Eelco Dolstra1-0/+1
2006-09-04 * Use a proper namespace.Eelco Dolstra1-1/+7
* Optimise header file usage a bit. * Compile the parser as C++.
2006-08-04 * Fix a few warnings.Eelco Dolstra1-2/+2
2006-07-28 * `nix-instantiate --print-args': print out the valid values forEelco Dolstra1-0/+24
functions arguments that have a domain.
2006-07-24 * New language feature: domain checks, which check whether a functionEelco Dolstra1-4/+5
argument has a valid value, i.e., is in a certain domain. E.g., { foo : [true false] , bar : ["a" "b" "c"] }: ... This previously could be done using assertions, but domain checks will allow the buildfarm to automatically extract the configuration space from functions.
2006-07-24 * Refactoring to support domain checks.Eelco Dolstra1-9/+6
2006-07-19 * Better error messages (especially wrt types).Eelco Dolstra1-3/+24
2006-07-11 * Doh! Of couse we cannot memoize across scopes.Eelco Dolstra1-4/+8
2006-05-04 * Use the new ATermMap.Eelco Dolstra1-124/+6
2006-05-02 * Use a linked list of substitutions. This reduces the amount ofEelco Dolstra1-14/+20
copying.
2006-05-02 * Removed a bunch of ATreverses.Eelco Dolstra1-1/+1
2006-05-02 * Memory reduction: replaced expensive calls to ATmakeApplList byEelco Dolstra1-11/+16
ATmakeApplArray, and got rid of ATreverse in substitute().
2006-05-02 * Some preliminaries towards NIX-45.Eelco Dolstra1-6/+11
2006-03-10 * In theory, this should reduce the number of ATermMapEelco Dolstra1-2/+3
re-allocations.
2005-11-04 * Memoise checkVarDefs since internally produced terms (i.e., not theEelco Dolstra1-9/+24
result of parsing) can have very heavy sharing, causing exponential complexity if we naively recurse into them. ATerms are graphs, not trees!
2005-07-19 * Prevent repeated wrapping of closed termsEelco Dolstra1-1/+6
(closed(closed(closed(...)))) since this reduces performance by producing bigger terms and killing caching (which incidentally also prevents useful infinite recursion detection).