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60 commits

Author SHA1 Message Date
Eelco Dolstra
0dbd4638e0 * Two primops: builtins.intersectAttrs and builtins.functionArgs.
intersectAttrs returns the (right-biased) intersection between two
  attribute sets, e.g. every attribute from the second set that also
  exists in the first.  functionArgs returns the set of attributes
  expected by a function.

  The main goal of these is to allow the elimination of most of
  all-packages.nix.  Most package instantiations in all-packages.nix
  have this form:

    foo = import ./foo.nix {
      inherit a b c;
    };

  With intersectAttrs and functionArgs, this can be written as:

    foo = callPackage (import ./foo.nix) { };

  where

   callPackage = f: args:
     f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args);

  I.e., foo.nix is called with all attributes from "pkgs" that it
  actually needs (e.g., pkgs.a, pkgs.b and pkgs.c).  (callPackage can
  do any other generic package-level stuff we might want, such as
  applying makeOverridable.)  Of course, the automatically supplied
  arguments can be overriden if needed, e.g.

    foo = callPackage (import ./foo.nix) {
      c = c_version_2;
    };

  but for the vast majority of packages, this won't be needed.

  The advantages are to reduce the amount of typing needed to add a
  dependency (from three sites to two), and to reduce the number of
  trivial commits to all-packages.nix.  For the former, there have
  been two previous attempts:

    - Use "args: with args;" in the package's function definition.
      This however obscures the actual expected arguments of a
      function, which is very bad.

    - Use "{ arg1, arg2, ... }:" in the package's function definition
      (i.e. use the ellipis "..." to allow arbitrary additional
      arguments), and then call the function with all of "pkgs" as an
      argument.  But this inhibits error detection if you call it with
      an misspelled (or obsolete) argument.
2009-09-15 13:01:46 +00:00
Eelco Dolstra
a64bbe049e * Change the scoping of "inherit (e) ..." in recs so that the
attributes of the rec are in scope of `e'.  This is useful in
  expressions such as

    rec {
      lib = import ./lib;
      inherit (lib) concatStrings;
    }

  It does change the semantics of expressions such as

    let x = {y = 1;}; in rec { x = {y = 2;}; inherit (x) y; }.y

  This now returns 2 instead of 1.  However, no code in Nixpkgs or
  NixOS seems to rely on the old behaviour.
2009-05-15 13:46:13 +00:00
Eelco Dolstra
d407d572fd * Some syntactic sugar for attribute sets: allow {x.y.z = ...;} as a
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'.
2009-05-15 12:35:23 +00:00
Eelco Dolstra
9279174dde * Added an experimental feature suggested by Andres: ellipses ("...")
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 14:00:44 +00:00
Eelco Dolstra
1b962fc720 * @-patterns as in Haskell. For instance, in a function definition
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 12:53:29 +00:00
Eelco Dolstra
efe4b690ae * Refactoring: combine functions that take an attribute set and
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.
2008-08-14 10:04:22 +00:00
Eelco Dolstra
5664b6d7ba * Removed the "valid values" feature. Nobody uses it anyway. 2008-08-11 13:36:40 +00:00
Eelco Dolstra
7cd88b1dec * Generalised the dependencyClosure primop to builtins.genericClosure,
which is hopefully more useful.
* New primops: length, mul, div.
2008-07-11 13:29:04 +00:00
Eelco Dolstra
d567baabbd * Export the nix-env derivation name parsing and version comparison
logic through the `parseDrvName' and `compareVersions' primops.
  This will allow expressions to easily check whether some dependency
  is a specific needed version or falls in some version range.  See
  tests/lang/eval-okay-versions.nix for examples.
2008-07-01 10:10:32 +00:00
Eelco Dolstra
4066f450c2 * Doh. 2008-02-05 13:35:49 +00:00
Eelco Dolstra
e7bdde981f * Regression test. 2008-02-05 13:25:18 +00:00
Eelco Dolstra
7d0f6aed59 * New primop `unsafeDiscardStringContext' to get rid of string
contexts.  Needed to prevent unnecessary dependencies when building
  the NixOS manual.
2008-01-04 14:22:49 +00:00
Eelco Dolstra
b42ef9c054 * Syntax to escape '', ${. 2007-12-06 10:20:58 +00:00
Eelco Dolstra
6d6c68c0d2 * Added a new kind of multi-line string literal delimited by two
single quotes.  Example (from NixOS):

    job = ''
      start on network-interfaces

      start script

        rm -f /var/run/opengl-driver
        ${if videoDriver == "nvidia"        
          then "ln -sf ${nvidiaDrivers} /var/run/opengl-driver"
          else if cfg.driSupport
          then "ln -sf ${mesa} /var/run/opengl-driver"
          else ""
        }

        rm -f /var/log/slim.log

      end script
    '';

  This style has two big advantages:

  - \, ' and " aren't special, only '' and ${.  So you get a lot less
    escaping in shell scripts / configuration files in Nixpkgs/NixOS.
    The delimiter '' is rare in scripts (and can usually be written as
    "").  ${ is also fairly rare.

    Other delimiters such as <<...>>, {{...}} and <|...|> were also
    considered but this one appears to have the fewest drawbacks
    (thanks Martin).

  - Indentation is intelligently stripped so that multi-line strings
    can follow the nesting structure of the containing Nix
    expression.  E.g. in the example above 6 spaces are stripped from
    the start of each line.  This prevents unnecessary indentation in
    generated files (which sometimes even breaks things).

  See tests/lang/eval-okay-ind-string.nix for some examples.
2007-11-30 16:48:45 +00:00
Eelco Dolstra
06f95dd07c * New primop `readFile' to get the contents of a file as a string. 2007-11-21 13:49:59 +00:00
Marc Weber
2629998e91 primop functions listToAttrs (+test), __isAttrs, __trace added
new configuration style proposal in lib/default-unstable.nix
2007-08-18 22:12:00 +00:00
Eelco Dolstra
ca00aa1171 * Allow empty argument lists in function definitions (e.g., `{}:
bla').  Also allow trailing commas (`{x, y,}: ...') as a unintented
  consequence.  Hopefully the reduce/reduce conflict won't cause any
  problems.
2007-05-15 12:14:37 +00:00
Eelco Dolstra
7349bd0176 New primitives:
* `sub' to subtract two numbers.
* `stringLength' to get the length of a string.
* `substring' to get a substring of a string.  These should be enough
  to allow most string operations to be expressed.
2007-01-29 14:23:09 +00:00
Eelco Dolstra
e418976107 * Option --argstr for passing string arguments easily. (NIX-75) 2007-01-14 12:32:44 +00:00
Eelco Dolstra
f23dcdd603 * Canonicalise ASTs in `nix-instantiate --eval': remove position
info, sort attribute sets.
2007-01-13 16:17:07 +00:00
Eelco Dolstra
1a7e88bbd9 * New built-in function `builtins.attrNames' that returns the
names of the attributes in an attribute set.
2006-12-12 16:14:31 +00:00
Eelco Dolstra
dfc042a0c1 * Another test. 2006-10-17 11:16:02 +00:00
Eelco Dolstra
9e30694f98 * Fix the tests wrt the AST changes, i.e., Str(s) -> Str(s, []), and
the semantic changes.
2006-10-17 11:08:59 +00:00
Eelco Dolstra
7d4567f2cc * Removed URIs from the evaluator (NIX-66). They are now just another
kind of notation for strings.
2006-10-11 21:59:33 +00:00
Eelco Dolstra
ac19b333b3 * Finally, a real "let" syntax: `let x = ...; ... z = ...; in ...'. 2006-10-02 15:52:44 +00:00
Eelco Dolstra
0e705391db * Primop `toPath' to convert a string to a path.
* Primop `pathExists' to check for path existence.
2006-09-24 18:23:32 +00:00
Eelco Dolstra
e47e0c2dbe * Builtin function `getEnv' for getting environment variables. 2006-09-24 17:48:41 +00:00
Eelco Dolstra
df8873e14a * lessThan primitive for integer comparison. 2006-09-24 15:21:48 +00:00
Eelco Dolstra
2ab4bc44c7 * Builtin function `add' to add integers.
* Put common test functions in tests/lang/lib.nix.
2006-09-22 15:29:21 +00:00
Eelco Dolstra
d315210612 * Added a builtin function `isList' to test whether a value is a list.
With this primitive, a list-flattening function can be implemented
  (NIX-55, example is in tests/lang/eval-okay-flatten.nix).
2006-09-22 14:55:19 +00:00
Eelco Dolstra
c02a44183f * Builtin functions head' and tail' to return the head and tail of
list.  Useful for lots of things, such as implementing a fold
  function (see NIX-30, example is in tests/lang/eval-okay-list.nix).
2006-09-22 14:46:36 +00:00
Eelco Dolstra
8a1ab709a4 * New builtin functions builtins.{hasAttr, getAttr} to check for
attribute existence and to return an attribute from an attribute
  set, respectively.  Example: `hasAttr "foo" {foo = 1;}'.  They
  differ from the `?' and `.' operators in that the attribute name is
  an arbitrary expression.  (NIX-61)
2006-09-22 14:31:55 +00:00
Eelco Dolstra
de90fdf908 * Allow "$" in strings as long as they are not followed by "{". (Too
bad flex doesn't have lexical restrictions, the current solution
  isn't quite right...)
2006-09-01 12:04:06 +00:00
Eelco Dolstra
f93f7b75be * Okay, that's a bit harder than expected. 2006-08-30 13:10:04 +00:00
Eelco Dolstra
dce1afdc67 * TDD: == should do a deep equality test, i.e., it should strictly
evaluate its arguments.
2006-08-30 12:25:27 +00:00
Eelco Dolstra
215ec2ddc6 * New primop __toXML (or builtins.toXML) to convert an expression to
an XML representation stored in a string.  This should be useful to
  pass structured information to builders.
2006-08-24 14:34:29 +00:00
Eelco Dolstra
38f18aa6d4 * New primop: abort "error message". 2006-08-23 15:46:00 +00:00
Eelco Dolstra
4a053bfdfd * A new primop `builtins', which returns an attribute set containing
all the primops.  This allows Nix expressions to test for new
  primops and take appropriate action if they're not available.  For
  instance, rather than calling a primop `foo' directly, they could
  say `if builtins ? foo then builtins.foo ... else ...'.
2006-08-23 14:39:11 +00:00
Eelco Dolstra
93d9797eda * Urgh (see NIX-56). 2006-08-22 09:34:38 +00:00
Eelco Dolstra
4874fd2d9a * Test for `nix-instantiate --eval-only --xml'. 2006-08-17 11:28:29 +00:00
Eelco Dolstra
fe101fa785 * Meh. 2006-08-16 10:29:43 +00:00
Eelco Dolstra
bfe19b3c37 * A test for NIX-53. 2006-08-16 10:23:02 +00:00
Eelco Dolstra
f4c5531d92 * New language feature: domain checks, which check whether a function
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 16:35:34 +00:00
Eelco Dolstra
b545c669a0 * Tests for domain checks. 2006-07-24 15:50:29 +00:00
Eelco Dolstra
57751fdb55 * Refactoring to support domain checks. 2006-07-24 15:16:03 +00:00
Eelco Dolstra
2b4b0658fa * This expression has an undefined variable which isn't detected, so
evaluation fails:

    error: impossible: undefined variable `gcc'
2006-07-10 17:35:00 +00:00
Eelco Dolstra
5cabd47394 * Allow function argument default values to refer to other arguments
of the function.  Implements NIX-45.
2006-05-08 12:52:47 +00:00
Eelco Dolstra
ae55e79541 * More tests. 2006-05-02 11:20:55 +00:00
Eelco Dolstra
dca43ef795 * Tests for NIX-45. 2006-05-02 11:15:04 +00:00
Eelco Dolstra
0064599a27 * String interpolation. Expressions like
"--with-freetype2-library=" + freetype + "/lib"

  can now be written as

    "--with-freetype2-library=${freetype}/lib"

  An arbitrary expression can be enclosed within ${...}, not just
  identifiers.

* Escaping in string literals: \n, \r, \t interpreted as in C, any
  other character following \ is interpreted as-is.
  
* Newlines are now allowed in string literals.
2006-05-01 14:01:47 +00:00