Commit graph

115 commits

Author SHA1 Message Date
Eelco Dolstra 81de12bc8f * Refactoring: move variable uses to a separate class. 2010-04-14 15:14:23 +00:00
Eelco Dolstra 110d155778 * Implemented withs. 2010-04-14 15:01:04 +00:00
Eelco Dolstra 9985230c00 * After parsing, compute level/displacement pairs for each variable
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 14:42:32 +00:00
Eelco Dolstra 85d13c8f93 * Change the semantics of "with" so that inner "withs" take
precedence, i.e. `with {x=1;}; with {x=2;}; x' evaluates to 2'.
  This has a simpler implementation and seems more natural.  There
  doesn't seem to be any code in Nixpkgs or NixOS that relies on the
  old behaviour.
2010-04-14 08:37:08 +00:00
Eelco Dolstra 816f9c0f6f * Use std::tr1::unordered_set instead of std::set for the symbol
table.  This gives a 10% speed increase on `nix-instantiate
  /etc/nixos/nixos -A system --readonly-mode'.
2010-04-13 14:34:11 +00:00
Eelco Dolstra 7d47498b5e * Evaluate lets directly (i.e. without desugaring to `rec { attrs...;
<let-body> = e; }.<let-body>).  This prevents the unnecessary
  allocation of an attribute set.
2010-04-13 13:42:25 +00:00
Eelco Dolstra ac1e8f40d4 * Use a symbol table to represent identifiers and attribute names
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.
2010-04-13 12:25:42 +00:00
Eelco Dolstra 10e8b1fd15 * Finished the ATerm-less parser. 2010-04-12 23:33:23 +00:00
Eelco Dolstra d4f0b0fc6c * Indented strings. 2010-04-12 22:03:27 +00:00
Eelco Dolstra a60317f20f * More missing constructs. 2010-04-12 21:21:24 +00:00
Eelco Dolstra 4d6ad5be17 * Don't use ATerms for the abstract syntax trees anymore. Not
finished yet.
2010-04-12 18:30:11 +00:00
Eelco Dolstra db90b88e65 * Hack to support builderDefs expressions. 2010-04-12 09:50:20 +00:00
Eelco Dolstra 4e49002576 * Doh. 2010-04-12 09:45:00 +00:00
Eelco Dolstra f3dc7ab877 * Keep more statistics about stack space usage.
* Reduce stack space usage.
2010-04-09 12:00:49 +00:00
Eelco Dolstra b7b3dd55f9 * Remove a lot of dead code. 2010-04-08 11:41:19 +00:00
Eelco Dolstra 7e048eddf5 * Fix blackholing. If evaluation fails due to an assertion failure,
then the blackhole has to be removed to ensure that repeated
  evaluation of the same value gives an assertion failure again rather
  than an "infinite recursion" error.
2010-04-08 11:25:14 +00:00
Eelco Dolstra af2a372bb0 * Update autoCallFunction() and findAlongAttrPath(). 2010-04-07 15:47:06 +00:00
Eelco Dolstra fc92244ba8 * Implemented the primops necessary for generating the NixOS manual. 2010-04-07 13:55:46 +00:00
Eelco Dolstra a353aef0b1 * In eval(), don't use the target value `v' as a temporary.
Overwriting `v' breaks when the expression evaluation to an
  assertion failure or throw.
2010-04-06 14:15:29 +00:00
Eelco Dolstra c172274e17 * Quick hack to make coerceToString work more or less correctly on
nested lists.  `nix-instantiate' can now evaluate the NixOS system
  derivation attribute correctly (in 2.1s on my laptop vs. 6.2s for
  the trunk).
2010-04-01 14:35:03 +00:00
Eelco Dolstra 7b851915bf * Improve sharing. 2010-04-01 12:04:57 +00:00
Eelco Dolstra 95cc417d76 * Functions are incomparable. 2010-04-01 10:55:36 +00:00
Eelco Dolstra 71f026292b * Make `derivation' lazy again for performance. It also turns out
that there are some places in Nixpkgs (php_configurable /
  composableDerivation, it seems) that call `derivation' with
  incorrect arguments (namely, the `name' attribute missing) but get
  away with it because of laziness.
2010-04-01 09:55:57 +00:00
Eelco Dolstra dc31305b38 * Fixed the trace primop and path comparison.
* Removed exprToString and stringToExpr because there is no ATerm
  representation to work on anymore (and exposing the internals of the
  evaluator like this is not a good idea anyway).
2010-03-31 20:09:20 +00:00
Eelco Dolstra 979f163615 * Handle string contexts. `nix-instantiate' can now correctly compute
the `firefoxWrapper' attribute in Nixpkgs, and it's about 3 times
  faster than the trunk :-)
2010-03-31 19:52:29 +00:00
Eelco Dolstra 55e207b2dc * Cache parse trees to prevent repeated parsing of imported Nix
expressions.
2010-03-31 16:14:32 +00:00
Eelco Dolstra 3d94be61ea * Implemented derivations. 2010-03-31 15:38:03 +00:00
Eelco Dolstra 13c2adc897 * Implemented `rec { inherit ...; }'. 2010-03-31 11:05:39 +00:00
Eelco Dolstra 4c53ca2692 * Compare nulls. 2010-03-31 09:54:12 +00:00
Eelco Dolstra 7f19e03c65 * More primops. 2010-03-30 22:39:48 +00:00
Eelco Dolstra 47df476daa * More operators / primops. 2010-03-30 18:05:54 +00:00
Eelco Dolstra c9170be2bd * More primops. 2010-03-30 15:18:20 +00:00
Eelco Dolstra c3aa615a5f * More primops. 2010-03-30 14:39:27 +00:00
Eelco Dolstra 5b72d8a749 * Implemented `map'. 2010-03-30 13:47:59 +00:00
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 50d11b90ca * Allow unsafe (unspecified) comparisons between attrsets unless
NIX_NO_UNSAFE_EQ is set, for now.
2009-05-12 11:06:24 +00:00
Eelco Dolstra c34e6d71bc * Disallow equality tests between attribute sets. This was always
broken, but now the evaluator checks for it to prevent Nix
  expressions from relying on undefined behaviour.  Equality tests are
  implemented using a shallow pointer equality test between ATerms.
  However, because attribute sets are lazy and contain position
  information, this can give false positives.  For instance,
  previously

    let y = {x = 1;}; in y == y

  evaluated to true, while the equivalent expression

    {x = 1;} == {x = 1;}

  evaluated to false.  So disallow these tests for now.  (Eventually
  we may want to implement deep equality tests for attribute sets,
  like lib.eqStrict.)
  
* Idem: disallow comparisons between functions.

* Implemented deep comparisons of lists.  This had the same problem as
  attribute sets - the elements in the list weren't evaluated.  For
  instance,

    ["xy"] == [("x" + "y")]

  evaluated to false.  Now it works properly.
2009-05-11 15:50:14 +00:00
Eelco Dolstra 99dc3e613a * Require that __overrides is defined as a non-recursive attribute
(which means it can only be defined via "inherit"), otherwise we get
  scoping bugs, since __overrides can't be recursive (or at least, it
  would be hard).
2008-08-26 14:05:59 +00:00
Michael Raskin b7ff182b6e Fixing an obvious typo in override code. I do not know whether it works correctly after the change, but at least it ca nbe compiled now. 2008-08-14 22:01:43 +00:00
Eelco Dolstra ca07f3e370 * Another experimental feature: a way to truly override attributes in
a rec.  This will be very useful to allow end-user customisation of
  all-packages.nix, for instance globally overriding GCC or some other
  dependency.  The // operator doesn't cut it: you could replace the
  "gcc" attribute, but all other attributes would continue to
  reference the original value due to the substitution semantics of
  rec.

  The syntax is a bit hacky but this is to allow backwards
  compatibility.
2008-08-14 16:59:37 +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 fc691e1cbd * Print a better error message when a non-derivation attribute set is
coerced to a string.
2008-07-24 14:52:25 +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 044b6482c1 * Greatly reduced the amount of stack space used by the Nix expression
evaluator.  This was important because the NixOS expressions started
  to hit 2 MB default stack size on Linux.

  GCC is really dumb about stack space: it just adds up all the local
  variables and temporaries of every scope into one huge stack frame.
  This is really bad for deeply recursive functions.  For instance,
  every `throw Error(format("error message"))' causes a format object
  of a few hundred bytes to be allocated on the stack.  As a result,
  every recursive call to evalExpr2() consumed 4680 bytes.  By
  splitting evalExpr2() and by moving the exception-throwing code out
  of the main functions, evalExpr2() now only consumes 40 bytes.
  Similar for evalExpr().
2007-02-27 19:10:45 +00:00