diff options
| -rw-r--r-- | src/libexpr/primops.cc | 66 | ||||
| -rw-r--r-- | tests/lang/eval-okay-functionargs.exp.xml | 15 | ||||
| -rw-r--r-- | tests/lang/eval-okay-functionargs.nix | 80 |
3 files changed, 161 insertions, 0 deletions
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 783d26c448..6408ca9569 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -812,6 +812,70 @@ static Expr prim_isAttrs(EvalState & state, const ATermVector & args) } +/* Return the right-biased intersection of two attribute sets as1 and + as2, i.e. a set that contains every attribute from as2 that is also + a member of as1. */ +static Expr prim_intersectAttrs(EvalState & state, const ATermVector & args) +{ + ATermMap as1, as2; + queryAllAttrs(evalExpr(state, args[0]), as1, true); + queryAllAttrs(evalExpr(state, args[1]), as2, true); + + ATermMap res; + foreach (ATermMap::const_iterator, i, as2) + if (as1[i->key]) res.set(i->key, i->value); + + return makeAttrs(res); +} + + +static void attrsInPattern(ATermMap & map, Pattern pat) +{ + ATerm name; + ATermList formals; + Pattern pat1, pat2; + ATermBool ellipsis; + if (matchAttrsPat(pat, formals, ellipsis)) { + for (ATermIterator i(formals); i; ++i) { + ATerm def; + if (!matchFormal(*i, name, def)) abort(); + map.set(name, makeAttrRHS(makeBool(def != constNoDefaultValue), makeNoPos())); + } + } + else if (matchAtPat(pat, pat1, pat2)) { + attrsInPattern(map, pat1); + attrsInPattern(map, pat2); + } +} + + +/* Return a set containing the names of the formal arguments expected + by the function `f'. The value of each attribute is a Boolean + denoting whether has a default value. For instance, + + functionArgs ({ x, y ? 123}: ...) + => { x = false; y = true; } + + "Formal argument" here refers to the attributes pattern-matched by + the function. Plain lambdas are not included, e.g. + + functionArgs (x: ...) + => { } +*/ +static Expr prim_functionArgs(EvalState & state, const ATermVector & args) +{ + Expr f = evalExpr(state, args[0]); + ATerm pat, body, pos; + if (!matchFunction(f, pat, body, pos)) + throw TypeError("`functionArgs' required a function"); + + ATermMap as; + attrsInPattern(as, pat); + + return makeAttrs(as); +} + + /************************************************************* * Lists *************************************************************/ @@ -1070,6 +1134,8 @@ void EvalState::addPrimOps() addPrimOp("__isAttrs", 1, prim_isAttrs); addPrimOp("removeAttrs", 2, prim_removeAttrs); addPrimOp("__listToAttrs", 1, prim_listToAttrs); + addPrimOp("__intersectAttrs", 2, prim_intersectAttrs); + addPrimOp("__functionArgs", 1, prim_functionArgs); // Lists addPrimOp("__isList", 1, prim_isList); diff --git a/tests/lang/eval-okay-functionargs.exp.xml b/tests/lang/eval-okay-functionargs.exp.xml new file mode 100644 index 0000000000..651f54c363 --- /dev/null +++ b/tests/lang/eval-okay-functionargs.exp.xml @@ -0,0 +1,15 @@ +<?xml version='1.0' encoding='utf-8'?> +<expr> + <list> + <string value="stdenv" /> + <string value="fetchurl" /> + <string value="aterm-stdenv" /> + <string value="aterm-stdenv2" /> + <string value="libX11" /> + <string value="libXv" /> + <string value="mplayer-stdenv2.libXv-libX11" /> + <string value="mplayer-stdenv2.libXv-libX11_2" /> + <string value="nix-stdenv-aterm-stdenv" /> + <string value="nix-stdenv2-aterm2-stdenv2" /> + </list> +</expr> diff --git a/tests/lang/eval-okay-functionargs.nix b/tests/lang/eval-okay-functionargs.nix new file mode 100644 index 0000000000..68dca62ee1 --- /dev/null +++ b/tests/lang/eval-okay-functionargs.nix @@ -0,0 +1,80 @@ +let + + stdenvFun = { }: { name = "stdenv"; }; + stdenv2Fun = { }: { name = "stdenv2"; }; + fetchurlFun = { stdenv }: assert stdenv.name == "stdenv"; { name = "fetchurl"; }; + atermFun = { stdenv, fetchurl }: { name = "aterm-${stdenv.name}"; }; + aterm2Fun = { stdenv, fetchurl }: { name = "aterm2-${stdenv.name}"; }; + nixFun = { stdenv, fetchurl, aterm }: { name = "nix-${stdenv.name}-${aterm.name}"; }; + + mplayerFun = + { stdenv, fetchurl, enableX11 ? false, xorg ? null, enableFoo ? true, foo ? null }: + assert stdenv.name == "stdenv2"; + assert enableX11 -> xorg.libXv.name == "libXv"; + assert enableFoo -> foo != null; + { name = "mplayer-${stdenv.name}.${xorg.libXv.name}-${xorg.libX11.name}"; }; + + makeOverridable = f: origArgs: f origArgs // + { override = newArgs: + makeOverridable f (origArgs // (if builtins.isFunction newArgs then newArgs origArgs else newArgs)); + }; + + callPackage_ = pkgs: f: args: + makeOverridable f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); + + allPackages = + { overrides ? (pkgs: pkgsPrev: { }) }: + let + callPackage = callPackage_ pkgs; + pkgs = pkgsStd // (overrides pkgs pkgsStd); + pkgsStd = { + inherit pkgs; + stdenv = callPackage stdenvFun { }; + stdenv2 = callPackage stdenv2Fun { }; + fetchurl = callPackage fetchurlFun { }; + aterm = callPackage atermFun { }; + xorg = callPackage xorgFun { }; + mplayer = callPackage mplayerFun { stdenv = pkgs.stdenv2; enableFoo = false; }; + nix = callPackage nixFun { }; + }; + in pkgs; + + libX11Fun = { stdenv, fetchurl }: { name = "libX11"; }; + libX11_2Fun = { stdenv, fetchurl }: { name = "libX11_2"; }; + libXvFun = { stdenv, fetchurl, libX11 }: { name = "libXv"; }; + + xorgFun = + { pkgs }: + let callPackage = callPackage_ (pkgs // pkgs.xorg); in + { + libX11 = callPackage libX11Fun { }; + libXv = callPackage libXvFun { }; + }; + +in + +let + + pkgs = allPackages { }; + + pkgs2 = allPackages { + overrides = pkgs: pkgsPrev: { + stdenv = pkgs.stdenv2; + nix = pkgsPrev.nix.override { aterm = aterm2Fun { inherit (pkgs) stdenv fetchurl; }; }; + xorg = pkgsPrev.xorg // { libX11 = libX11_2Fun { inherit (pkgs) stdenv fetchurl; }; }; + }; + }; + +in + + [ pkgs.stdenv.name + pkgs.fetchurl.name + pkgs.aterm.name + pkgs2.aterm.name + pkgs.xorg.libX11.name + pkgs.xorg.libXv.name + pkgs.mplayer.name + pkgs2.mplayer.name + pkgs.nix.name + pkgs2.nix.name + ] |