Commit graph

184 commits

Author SHA1 Message Date
Eelco Dolstra d78a05ab40 * Make `import' work. 2010-03-30 09:22:33 +00:00
Eelco Dolstra 31428c3a06 * Started integrating the new evaluator. 2010-03-29 14:37:56 +00:00
Eelco Dolstra 8a10360c91 * Simplify @-patterns: only {attrs}@name' or name@{attrs}' are now
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.
2010-03-25 12:19:41 +00:00
Eelco Dolstra deb342fb08 * builtins.trace: in the common case that the value is a string, then
show the string, not the ATerm, so we get `trace: bla' instead of
  `trace: Str("bla",[])'.
2009-10-22 08:10:12 +00:00
Eelco Dolstra 437077c39d * Added a primop unsafeDiscardOutputDependency needed by Disnix to
pass derivation paths to a builder without actually building them.
2009-10-21 15:05:30 +00:00
Eelco Dolstra 1332dd1ed3 * tryEval shouldn't catch all exceptions of type Error, since not all
of them leave the evaluator in a continuable state.  Also, it should
  be less chatty.
2009-09-23 19:19:26 +00:00
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
Michael Raskin 3bca8931e8 Adding tryEval builtin. It allows to catch presence of errors in an expression. 2009-08-25 16:06:46 +00:00
Eelco Dolstra f2c3fc5191 * Don't show trace information by default (`--show-trace' to enable).
NixOS evaluation errors in particular look intimidating and
  generally aren't very useful.  Ideally the builtins.throw messages
  should be self-contained.
2009-06-30 13:28:29 +00:00
Eelco Dolstra 2897286487 * Unify exportReferencesGraph and exportBuildReferencesGraph, and make
sure that it works as expected when you pass it a derivation.  That
  is, we have to make sure that all build-time dependencies are built,
  and that they are all in the input closure (otherwise remote builds
  might fail, for example).  This is ensured at instantiation time by
  adding all derivations and their sources to inputDrvs and inputSrcs.
2009-03-18 17:36:42 +00:00
Marc Weber 1407a1ec99 added primop functions __isBool, __isString, __isInt 2009-02-05 19:35:40 +00:00
Nicolas Pierron 110606d470 Add the "addErrorContext" builtin to add more information in the stack trace. 2009-01-27 14:36:44 +00:00
Eelco Dolstra 63b8f09d8d 2008-12-04 10:45:47 +00:00
Eelco Dolstra f8713e1287 * Dirty hack to make nix-push work properly on derivations: the
derivation should be a source rather than a derivation dependency of
  the call to the NAR derivation.  Otherwise the derivation (and all
  its dependencies) will be built as a side-effect, which may not even
  succeed.
2008-12-04 10:40:41 +00:00
Eelco Dolstra ff762fb499 * Pass HashType values instead of strings. 2008-12-03 16:10:17 +00:00
Eelco Dolstra 1307b22223 * Made addToStore() a lot more efficient: it no longer reads the path
being copied 3 times in the worst case.  It doesn't run in constant space,
  but it didn't do that anyway.
2008-12-03 15:51:17 +00:00
Eelco Dolstra 64519cfd65 * Unify the treatment of sources copied to the store, and recursive
SHA-256 outputs of fixed-output derivations.  I.e. they now produce
  the same store path:

  $ nix-store --add x
  /nix/store/j2fq9qxvvxgqymvpszhs773ncci45xsj-x

  $ nix-store --add-fixed --recursive sha256 x
  /nix/store/j2fq9qxvvxgqymvpszhs773ncci45xsj-x

  the latter being the same as the path that a derivation

    derivation {
      name = "x";
      outputHashAlgo = "sha256";
      outputHashMode = "recursive";
      outputHash = "...";
      ...
    };

  produces.

  This does change the output path for such fixed-output derivations.
  Fortunately they are quite rare.  The most common use is fetchsvn
  calls with SHA-256 hashes.  (There are a handful of those is
  Nixpkgs, mostly unstable development packages.)
  
* Documented the computation of store paths (in store-api.cc).
2008-12-03 15:06:30 +00:00
Eelco Dolstra aab530e971 * Primop builtins.storePath for declaring a store path as a
dependency.  `storePath /nix/store/bla' gives exactly the same
  result as `toPath /nix/store/bla', except that the former includes
  /nix/store/bla in the dependency context of the string.

  Useful in some generated Nix expressions like nix-push, which now
  finally does the right thing wrt distributed builds.  (Previously
  the path to be packed wasn't an explicit dependency, so it wouldn't
  be copied to the remote machine.)
2008-11-19 23:26:19 +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 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
Michael Raskin 5b5a3af983 Probably fixed __exprToString 2008-01-20 20:44:03 +00:00
Michael Raskin 5eb5c23447 Fixed exportBuildReferenceGraph 2008-01-15 04:32:08 +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 dedd62dd0c * More release notes. 2007-12-31 00:08:09 +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
Eelco Dolstra fa44e401a8 * Documented multi-user Nix. 2007-10-31 18:01:56 +00:00
Eelco Dolstra 0b4ed64d29 * "trace" primop: write the trace to standard error. 2007-10-26 18:25:50 +00:00
Eelco Dolstra 27a0662828 * listToAttrs: the list now should consist of {name, value} attribute
sets instead of {attr, value}.  "name" is better than "attr" because
  the *combination* of the two forms the attribute.
2007-10-09 12:51:25 +00:00
Eelco Dolstra f3441e6122 * Pass various options to the worker so that flags like -K or -j work
in multi-user Nix (NIX-72).
* Client/worker: exchange a protocol version number for future
  compatibility.
2007-09-18 09:11:20 +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 bddc83a148 * New builtin function "isFunction". You're not supposed to use it
;-)
* Channels: fix channels that are plain lists of derivations (like
  strategoxt-unstable) instead  of functions (like nixpkgs-unstable).
  This fixes the error message "error: the left-hand side of the
  function call is neither a function nor a primop (built-in
  operation) but a list".
2007-05-16 16:17:04 +00:00
Eelco Dolstra 5f2492eaec * New primop "throw <string>" to throw an error. This is like abort,
only thrown errors are caught by the top-level derivation evaluation
  in nix-env -qa / -i.
2007-04-16 15:03:19 +00:00
Eelco Dolstra b618fa6eb6 * computeStorePathForText: take the references into account when
computing the store path (NIX-77).  This is an important security
  property in multi-user Nix stores.

  Note that this changes the store paths of derivations (since the
  derivation aterms are added using addTextToStore), but not most
  outputs (unless they use builtins.toFile).
2007-01-29 15:51:37 +00:00
Eelco Dolstra c558b1583c * Don't capitalise the primop functions. 2007-01-29 15:15:37 +00:00
Eelco Dolstra 18e6096105 * Organise primops.cc a bit better. 2007-01-29 15:11:32 +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 7dedbd896a * filterSource: pass strings to the predicate function instead of
paths.  Paths can have unexpected semantics.
2007-01-29 13:32:50 +00:00
Eelco Dolstra e4b0666f8e * builtins.filterSource: pass the type of the file ("regular",
"directory", "symlink") as the second argument to the filter
  predicate.
2007-01-15 08:54:51 +00:00
Eelco Dolstra 11158028be * Cleanup. 2007-01-13 14:21:49 +00:00
Eelco Dolstra 1073b1780a * Remove debug message. 2006-12-13 14:29:05 +00:00
Eelco Dolstra a3e6415ba8 * New primop builtins.filterSource, which can be used to filter files
from a source directory.  All files for which a predicate function
  returns true are copied to the store.  Typical example is to leave
  out the .svn directory:

    stdenv.mkDerivation {
      ...
      src = builtins.filterSource
        (path: baseNameOf (toString path) != ".svn")
        ./source-dir;
      # as opposed to
      #   src = ./source-dir;
    }

  This is important because the .svn directory influences the hash in
  a rather unpredictable and variable way.
2006-12-12 23:05:01 +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 fcd9900d74 * Replace read-only calls to addTextToStore. 2006-12-01 21:00:39 +00:00
Eelco Dolstra 6ecb840fd1 * Put building in the store API. 2006-11-30 18:02:04 +00:00
Eelco Dolstra e2ef5e07fd * Refactoring. There is now an abstract interface class StoreAPI
containing functions that operate on the Nix store.  One
  implementation is LocalStore, which operates on the Nix store
  directly.  The next step, to enable secure multi-user Nix, is to
  create a different implementation RemoteStore that talks to a
  privileged daemon process that uses LocalStore to perform the actual
  operations.
2006-11-30 17:43:04 +00:00
Eelco Dolstra 7e85a2af5f * Fix importing of derivation outputs. 2006-11-03 16:17:39 +00:00
Eelco Dolstra dd300fb48d * Some better error messages. 2006-10-23 16:45:19 +00:00
Eelco Dolstra 17f4883bfe * Better message. 2006-10-19 17:43:58 +00:00
Eelco Dolstra 9bd93f7606 * toFile: maintain the references. 2006-10-19 17:39:02 +00:00
Eelco Dolstra 3059df0f1e * baseNameOf: paths don't have to be absolute. 2006-10-17 12:34:13 +00:00
Eelco Dolstra be1961c9f8 * toPath: should be the identity on paths. 2006-10-17 11:07:11 +00:00
Eelco Dolstra cba913c521 * dirOf: return a path if the argument is a path. 2006-10-17 11:05:34 +00:00
Eelco Dolstra cf705eaf78 * toString: don't copy paths. So toString can be used to pass
non-store paths to a builder.
2006-10-17 10:58:12 +00:00
Eelco Dolstra d7efd76394 * Big cleanup of the semantics of paths, strings, contexts, string
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'.)
2006-10-16 15:55:34 +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 0c4c5c2020 * Quick hack to fix NIX-67: evaluation result differing if the Nix
expression resides in the store.
2006-10-10 21:23:35 +00:00
Eelco Dolstra bd0c40e1e9 * import': unwrap the context. Necessary to make import (x + y)'
work, where x is a store path.
2006-10-10 15:07:23 +00:00
Eelco Dolstra 5fd44654db * toXML: propagate the context to allow derivations to be used in the
argument.
2006-10-03 15:38:59 +00:00
Eelco Dolstra d20c3011a0 * toFile: added an additional argument to specify the store path
suffix, e.g., `builtins.toFile "builder.sh" "..."'.
* toFile: handle references to other files correctly.
2006-10-03 14:55:54 +00:00
Eelco Dolstra e347033f71 * The result of a concatenation with a derivation on the left-hand
side should be a path, I guess.
* Handle paths that are in the store but not direct children of the
  store directory.
* Ugh, hack to prevent double context wrapping.
2006-09-24 21:39:57 +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 4e91d8621f * Fix comment. 2006-09-21 18:52:05 +00:00
Eelco Dolstra 0623359fbc * Print a better error message for wrong hashes (NIX-49). 2006-09-20 16:15:32 +00:00
Eelco Dolstra 75068e7d75 * Use a proper namespace.
* Optimise header file usage a bit.
* Compile the parser as C++.
2006-09-04 21:06:23 +00:00
Eelco Dolstra 7974aae81c * New primop: builtins.toFile, which writes a string into the store
and returns its path.  This can be used to (for instance) write
  builders inside a Nix expression, e.g.,

  stdenv.mkDerivation {
    builder = "
      source $stdenv/setup
      ...
    ";
    ...
  }
2006-09-01 12:07:31 +00:00
Eelco Dolstra 547b119f25 * Support singleton values and nested lists again in `args', but print
a warning.
2006-08-29 15:40:49 +00:00
Eelco Dolstra 2132d9ddeb * Fix the ~ operator. 2006-08-29 15:29:38 +00:00
Eelco Dolstra 1ec9f55741 * In toString, deal with nested lists properly (i.e., flatten them). 2006-08-28 21:47:42 +00:00
Eelco Dolstra 1fca76870b * Removed processBinding, instead we now apply toString to all
derivation attributes to flatten them into strings.  This is
  possible since string can nowadays be wrapped in contexts that
  describe the derivations/sources referenced by the evaluation of the
  string.
2006-08-28 13:31:06 +00:00
Eelco Dolstra 8a6080eb14 * Refactoring. 2006-08-26 16:48:01 +00:00
Eelco Dolstra 4b66cebe7b * Remove those storePath attribute sets, we don't need 'em. 2006-08-25 17:09:55 +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 b19cebc513 * Quotes. 2006-08-23 15:46:27 +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 a18d02e0b0 * Print a warning that the subpath operator (~) is deprecated. 2006-08-09 15:08:47 +00:00
Eelco Dolstra 4f3725b167 * Better error messages (especially wrt types). 2006-07-19 15:36:15 +00:00
Eelco Dolstra 9d72bf8835 * 64-bit compatibility fixes (for problems revealed by building on an Athlon
64 running 64-bit SUSE).  A patched ATerm library is required to run Nix
  succesfully.
2006-05-11 02:19:43 +00:00
Eelco Dolstra 0832956089 * Use the new ATermMap. 2006-05-04 12:21:08 +00:00
Eelco Dolstra 6cecad2be0 * Allow string concatenations involving derivations, e.g.,
configureFlags = "--with-freetype2-library="
      + freetype + "/lib";
2006-05-01 09:56:56 +00:00
Eelco Dolstra ef2d4a2da9 * Print a more useful stack trace when an error occurs deep in the
derivation dependency graph.
2006-03-24 14:02:44 +00:00
Eelco Dolstra 37d1b1cafd * `nix-env -qa --description' shows human-readable descriptions of
packages (provided that they have a `meta.description' attribute).
  E.g.,

  $ ./src/nix-env/nix-env -qa --description gcc
  gcc-4.0.2   GNU Compiler Collection, 4.0.x (cross-compiler for sparc-linux)
  gcc-4.0.2   GNU Compiler Collection, 4.0.x (cross-compiler for mips-linux)
  gcc-4.0.2   GNU Compiler Collection, 4.0.x (cross-compiler for arm-linux)
  gcc-4.0.2   GNU Compiler Collection, 4.0.x
2006-03-10 16:20:42 +00:00
Eelco Dolstra 922697c8b2 * Big speedup (factor > 2.5) in all nix-env operations that do actual
instantiation, e.g. "nix-env -i" and "nix-env -qas" (but not
  "nix-env -qa").  It turns out that many redundant calls to
  addToStore(path) were made, which reads and hashes the entire path.
  For instance, the bash bootstrap binary in Nixpkgs would be read and
  hashed many times.  As a result nix-env would spend around 92% of
  its time in the function sha256_block (according to callgrind).
  Some simple memoization fixes this.
2006-03-09 15:09:18 +00:00
Eelco Dolstra 9088dee9e2 * Some refactoring of the exception handling code so that we can catch
Nix expression assertion failures.
2006-03-08 14:11:19 +00:00
Eelco Dolstra c8bfb11b34 * `nix-env (-i|-u) --dry-run' now shows exactly which missing paths
will be built or substituted.
2006-03-06 11:21:15 +00:00
Eelco Dolstra cf2bb91ec8 * Missing #include. 2005-09-13 13:17:01 +00:00
Eelco Dolstra e1a6fb7870 * `dependencyClosure' now allows a search path, e.g.,
dependencyClosure { ... searchPath = [ ../foo ../bar ]; ... }

* Primop `dirOf' to return the directory part of a path (e.g., dirOf
  /a/b/c == /a/b).

* Primop `relativise' (according to Webster that's a real word!) that
  given paths A and B returns a string representing path B relative
  path to A; e.g., relativise /a/b/c a/b/x/y => "../x/y".
2005-08-14 14:00:39 +00:00
Eelco Dolstra 08c53923db * A primitive operation `dependencyClosure' to do automatic dependency
determination (e.g., finding the header files dependencies of a C
  file) in Nix low-level builds automatically.

  For instance, in the function `compileC' in make/lib/default.nix, we
  find the header file dependencies of C file `main' as follows:

    localIncludes =
      dependencyClosure {
        scanner = file:
          import (findIncludes {
            inherit file;
          });
        startSet = [main];
      };

  The function works by "growing" the set of dependencies, starting
  with the set `startSet', and calling the function `scanner' for each
  file to get its dependencies (which should yield a list of strings
  representing relative paths).  For instance, when `scanner' is
  called on a file `foo.c' that includes the line

    #include "../bar/fnord.h"

  then `scanner' should yield ["../bar/fnord.h"].  This list of
  dependencies is absolutised relative to the including file and added
  to the set of dependencies.  The process continues until no more
  dependencies are found (hence its a closure).

  `dependencyClosure' yields a list that contains in alternation a
  dependency, and its relative path to the directory of the start
  file, e.g.,

    [ /bla/bla/foo.c
      "foo.c"
      /bla/bar/fnord.h
      "../bar/fnord.h"
    ]

  These relative paths are necessary for the builder that compiles
  foo.c to reconstruct the relative directory structure expected by
  foo.c.

  The advantage of `dependencyClosure' over the old approach (using
  the impure `__currentTime') is that it's completely pure, and more
  efficient because it only rescans for dependencies (i.e., by
  building the derivations yielded by `scanner') if sources have
  actually changed.  The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
Eelco Dolstra 991a130b1e * Added a list concatenation operator:
[1 2 3] ++ [4 5 6] => [1 2 3 4 5 6]
2005-07-25 15:05:34 +00:00
Eelco Dolstra 040140dd1c * Added a primop `removeAttrs' to remove attributes from a set, e.g.,
`removeAttrs attrs ["x", "y"]' returns the set `attrs' with the
  attributes named `x' and `y' removed.  It is not an error for the
  named attributes to be missing from the input set.
2005-05-18 17:19:21 +00:00
Eelco Dolstra 77557a6f06 Commit 3000!
* Make the `derivation' primitive much more lazy.  The expression
  `derivation attrs' now evaluates to (essentially)

    attrs // {
      type = "derivation";
      outPath = derivation! attrs;
      drvPath = derivation! attrs;
    }

  where `derivation!' is a primop that does the actual derivation
  instantiation (i.e., it does what `derivation' used to do).  The
  advantage is that it allows commands such as `nix-env -qa' and
  `nix-env -i' to be much faster since they no longer need to
  instantiate all derivations, just the `name' attribute.  (However,
  `nix-env' doesn't yet take advantage of this since it still always
  evaluates the `outPath' and `drvPath' attributes).

  Also, this allows derivations to cyclically reference each other,
  for example,

    webServer = derivation {
      ...
      hostName = "svn.cs.uu.nl";
      services = [svnService];
    };

    svnService = derivation {
      ...
      hostName = webServer.hostName;
    };

  Previously, this would yield a black hole (infinite recursion).
2005-05-07 21:48:49 +00:00
Eelco Dolstra 02f2da0142 * Merging from nix-make branch:
- Add __currentTime primitive (dangerous!).
  - Allow imports of derivations.
2005-05-02 14:44:58 +00:00
Eelco Dolstra c9c58dba55 * Primop `__currentSystem' to return the current platform identifier. 2005-04-10 17:38:19 +00:00