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2006-03-08 * When obtaining derivations from Nix expressions, ignore allEelco Dolstra1-1/+7
expressions that cause an assertion failure (like `assert system == "i686-linux"'). This allows all-packages.nix in Nixpkgs to be used on all platforms, even if some Nix expressions don't work on all platforms. Not sure if this is a good idea; it's a bit hacky. In particular, due to laziness some derivations might appear in `nix-env -qa' but disappear in `nix-env -qas' or `nix-env -i'. Commit 5000!
2006-03-08 * Some refactoring of the exception handling code so that we can catchEelco Dolstra1-13/+19
Nix expression assertion failures.
2005-07-25 * Added a list concatenation operator:Eelco Dolstra1-0/+16
[1 2 3] ++ [4 5 6] => [1 2 3 4 5 6]
2004-11-03 * string2ATerm -> overloaded toATerm.Eelco Dolstra1-4/+4
2004-10-29 * Drop ATmake / ATMatcher also in handling store expressions.Eelco Dolstra1-2/+2
2004-10-26 * Don't use ATmake / ATmatch anymore, nor the ATMatcher class.Eelco Dolstra1-88/+72
Instead we generate data bindings (build and match functions) for the constructors specified in `constructors.def'. In particular this removes the conversions between AFuns and strings, and Nix expression evaluation now seems 3 to 4 times faster.
2004-10-26 * Doh!Eelco Dolstra1-1/+1
2004-10-26 * String/path concatenation operator (`+').Eelco Dolstra1-0/+14
2004-10-25 * New language feature: with expressions.Eelco Dolstra1-4/+24
The expression `with E1; E2' evaluates to E2 with all bindings in the attribute set E1 substituted. E.g., with {x = 123;}; x evaluates to 123. That is, the attribute set E1 is in scope in E2. This is particularly useful when importing files containing lots definitions. E.g., instead of let { inherit (import ./foo.nix) a b c d e f; body = ... a ... f ...; } we can now say with import ./foo.nix; ... a ... f ... I.e., we don't have to say what variables should be brought into scope.
2004-08-04 * Every real language has a `map' function.Eelco Dolstra1-1/+1
2004-08-04 * Allow primops with more that 1 arguments.Eelco Dolstra1-44/+37
2004-04-05 * When something goes wrong in the evaluation of a Nix expression,Eelco Dolstra1-29/+55
print a nice backtrace of the stack, rather than vomiting a gigantic (and useless) aterm on the screen. Example: error: while evaluating file `.../pkgs/system/test.nix': while evaluating attribute `subversion' at `.../pkgs/system/all-packages-generic.nix', line 533: while evaluating function at `.../pkgs/applications/version-management/subversion/default.nix', line 1: assertion failed at `.../pkgs/applications/version-management/subversion/default.nix', line 13 Since the Nix expression language is lazy, the trace may be misleading. The purpose is to provide a hint as to the location of the problem.
2004-03-30 * The recent change in nixpkgs of calling `stdenv.mkDerivation'Eelco Dolstra1-0/+5
instead of `derivation' triggered a huge slowdown in the Nix expression evaluator. Total execution time of `nix-env -qa' went up by a factor of 60 or so. This scalability problem was caused by expressions such as (x: y: ... x ...) a b where `a' is a large term (say, the one in `all-packages-generic.nix'). Then the first beta-reduction would produce (y: ... a ...) b by substituting `a' for `x'. The second beta-reduction would then substitute `b' for `y' into the body `... a ...', which is a large term due to `a', and thus causes a large traversal to be performed by substitute() in the second reduction. This is however entirely redundant, since `a' cannot contain free variables (since we never substitute below a weak head normal form). The solution is to wrap substituted terms into a `Closed' constructor, i.e., subst(subs, Var(x)) = Closed(e) iff subs[x] = e have substitution not descent into closed terms, subst(subs, Closed(x)) = Closed(x) and otherwise ignore them for evaluation, eval(Closed(x)) = eval(x). * Fix a typo that caused incorrect substitutions to be performed in simple lambdas, e.g., `(x: x: x) a' would reduce to `(x: a)'.
2004-03-28 * Added an operator `?' to test for attribute existence, e.g.,Eelco Dolstra1-1/+8
`attrs ? x' yields true iff `attrs' has an attribute named `x'.
2004-03-28 * Added an operator `~' to select paths within a derivation. E.g.,Eelco Dolstra1-0/+1
{stdenv, bash}: derivation { builder = bash ~ /bin/sh; args = ["-e" "-x" ./builder.sh]; ... } Here the attribute `builder' will evaluate to, e.g., `/nix/store/1234abcd...-bash-2.0.1/bin/sh'.
2004-03-28 * Added plain lambdas, e.g., `let { id = x: x; const = x: y: x; }'.Eelco Dolstra1-0/+7
`bla:' is now no longer parsed as a URL. * Re-enabled support for the `args' attribute in derivations to specify command line arguments to the builder, e.g., ... builder = /usr/bin/python; args = ["-c" ./builder.py]; ...
2004-03-19 * `null' is a normal form.Eelco Dolstra1-8/+11
2004-02-16 * Inherited attributes in recursive attribute sets are in scope of theEelco Dolstra1-6/+7
non-inherited attributes.
2004-02-04 * An attribute set update operator (//). E.g.,Eelco Dolstra1-0/+16
{x=1; y=2; z=3;} // {y=4;} => {x=1; y=4; z=3;}
2004-02-04 * Use a map to lookup primops.Eelco Dolstra1-15/+53
* Various performance improvements in the evaluator. * Do not link against unused (and missing!) libraries (-lsglr, etc.).
2004-02-03 * Verify that all variables in a Nix expression are defined.Eelco Dolstra1-9/+9
2004-02-02 * Added syntactic sugar to the construction of attribute sets toEelco Dolstra1-13/+17
`inherit' variables from the surrounding lexical scope. E.g., {stdenv, libfoo}: derivation { builder = ./bla; inherit stdenv libfoo; xyzzy = 1; } is equivalent to {stdenv, libfoo}: derivation { builder = ./bla; stdenv = stdenv; libfoo = libfoo; xyzzy = 1; } Note that for mutually recursive attribute set definitions (`rec {...}'), this also works, that is, `rec {inherit x;}' is equivalent to `let {fresh = x; body = rec {x = fresh;};}', *not* `rec {x = x}'.
2004-01-30 * Replaced the SDF parser by a substantially faster Bison/FlexEelco Dolstra1-0/+2
parser (roughly 80x faster). The absolutely latest version of Bison (1.875c) is required for reentrant GLR support, as well as a recent version of Flex (say, 2.5.31). Note that most Unix distributions ship with the prehistoric Flex 2.5.4, which doesn't support reentrancy.
2004-01-15 * Catch SIGINT to terminate cleanly when the user tries to interruptEelco Dolstra1-0/+2
Nix. This is to prevent Berkeley DB from becoming wedged. Unfortunately it is not possible to throw C++ exceptions from a signal handler. In fact, you can't do much of anything except change variables of type `volatile sig_atomic_t'. So we set an interrupt flag in the signal handler and check it at various strategic locations in the code (by calling checkInterrupt()). Since this is unlikely to cover all cases (e.g., (semi-)infinite loops), sometimes SIGTERM may now be required to kill Nix.
2003-11-25 * Allow integer bindings in derivations.Eelco Dolstra1-0/+1
2003-11-19 * Refactoring: put the Nix expression evaluator in its own library soEelco Dolstra1-0/+265
that it can be used by multiple programs.