Commit graph

232 commits

Author SHA1 Message Date
Eelco Dolstra cfd74aef1e
Fix eval-okay-fromTOML test
Turns out we were mis-parsing single-quoted attributes, e.g. 'key2'.
2019-05-29 12:12:02 +02:00
Eelco Dolstra 9eaebbf575
Merge branch 'attrPaths' of https://github.com/NinjaTrappeur/nix 2019-05-28 22:59:05 +02:00
Will Dietz a834861876
fix hashfile test that wasn't failing due to eval laziness
See:
7becb1bf1c (r33450554)
2019-05-08 10:04:54 +02:00
Daniel Schaefer 3f192ac80c Add builtins.hashFile
For text files it is possible to do it like so:
`builtins.hashString "sha256" (builtins.readFile /tmp/a)`
but that doesn't work for binary files.

With builtins.hashFile any kind of file can be conveniently hashed.
2019-05-03 17:23:36 +02:00
Eelco Dolstra e489f5cabf Update eval-okay-types.exp to match #1828 2019-03-27 21:07:04 +01:00
Jonas Chevalier 514b3c7f83
Add isPath primop
this is added for completeness' sake since all the other possible
`builtins.typeOf` results have a corresponding `builtins.is<Type>`
2019-03-24 11:36:49 +01:00
Shea Levy b30be6b450
Add builtins.appendContext.
A partner of builtins.getContext, useful for the same reasons.
2019-01-31 08:52:23 -05:00
Shea Levy 1d757292d0
Add builtins.getContext.
This can be very helpful when debugging, as well as enabling complex
black magic like surgically removing a single dependency from a
string's context.
2019-01-14 11:27:10 -05:00
Eelco Dolstra 9b1bdf2db8
FIx floating point evaluation
Fixes #2361.
2018-08-19 11:59:49 +02:00
volth 403a76a18f lib.concatMap and lib.mapAttrs to be builtins 2018-07-05 02:54:09 +00:00
Eelco Dolstra 3b1f54cf06
Add a fromTOML primop
This is primarily useful for processing Cargo.lock files.
2018-07-03 18:39:36 +02:00
volth 88c1ea30e4 add docs and tests 2018-05-24 12:51:34 +00:00
Eelco Dolstra 1ad19232c4
Don't return negative numbers from the flex tokenizer
Fixes #1374.
Closes #2129.
2018-05-11 12:05:12 +02:00
Eelco Dolstra 548ad391d9
Fix builtins.add test
Nix prints the floating point number 4.0 as "4".
2018-05-02 13:49:32 +02:00
Félix Baylac-Jacqué b2f3a7411a
nix-lang: Add deep nested mixed attrs test case. 2018-05-01 14:42:34 +02:00
Tim Sears 9a714f75af
add tests for builtins.add 2018-04-29 12:03:42 -07:00
Shea Levy e2b028353b
Merge branch 'pos-crash-fix' of git://github.com/dezgeg/nix 2018-04-23 08:43:54 -04:00
Shea Levy 0aae411eaa
Merge branch 'add-test-eval-okay-nested-with' of git://github.com/ryantrinkle/nix 2018-04-23 08:43:14 -04:00
Félix Baylac-Jacqué 00584bb091
parser: Allow mixed nested and top-level attrpaths
Fixes #2077.
2018-04-18 18:44:38 +02:00
Félix Baylac-Jacqué 10d33452e2
nix-lang parser: Add mixed nested attrs tests.
Part of issue #2077
2018-04-17 09:13:01 +02:00
Doug Beardsley 72902ec399 Add missing eval-okay-regex-split.exp test file 2018-04-06 12:18:59 -06:00
Tuomas Tynkkynen af86132e1a libexpr: Make unsafeGetAttrPos not crash on noPos
Currently e.g. `builtins.unsafeGetAttrPos "abort" builtins` will
eventually segfault because pos->file is an unset Symbol.

Found by afl-fuzz.
2018-04-03 15:54:42 +03:00
Ryan Trinkle f2273b11f5 Add test eval-okay-nested-with 2018-03-30 15:41:16 -04:00
Tuomas Tynkkynen a0e38c16bc libexpr: Recognize newline in more places in lexer
Flex's regexes have an annoying feature: the dot matches everything
except a newline. This causes problems for expressions like:

"${0}\
"

where the backslash-newline combination matches this rule instead of the
intended one mentioned in the comment:

    <STRING>\$|\\|\$\\ {
                    /* This can only occur when we reach EOF, otherwise the above
                    (...|\$[^\{\"\\]|\\.|\$\\.)+ would have triggered.
                    This is technically invalid, but we leave the problem to the
                    parser who fails with exact location. */
                    return STR;
                }
However, the parser actually accepts the resulting token sequence
('"' DOLLAR_CURLY 0 '}' STR '"'), which is a problem because the lexer
rule didn't assign anything to yylval. Ultimately this leads to a crash
when dereferencing a NULL pointer in ExprConcatStrings::bindVars().

The fix does change the syntax of the language in some corner cases
but I think it's only turning previously invalid (or crashing) syntax
to valid syntax. E.g.

"a\
b"

and

''a''\
b''

were previously syntax errors but now both result in "a\nb".

Found by afl-fuzz.
2018-03-02 17:30:48 +02:00
Tuomas Tynkkynen 77e9e1ed91 libexpr: Fix prim_replaceStrings() to work on an empty source string
Otherwise, running e.g.

nix-instantiate --eval -E --strict 'builtins.replaceStrings [""] ["X"] "abc"'

would just hang in an infinite loop.

Found by afl-fuzz.

First attempt of this was reverted in e2d71bd186 because it caused
another infinite loop, which is fixed now and a test added.
2018-02-26 19:49:13 +02:00
Eelco Dolstra e2d71bd186
Revert "libexpr: Fix prim_replaceStrings() to work on an empty source string"
This reverts commit 4ea9707591.

It causes an infinite loop in Nixpkgs evaluation,
e.g. "nix-instantiate -A hello" hung.

PR #1886.
2018-02-21 15:35:28 +01:00
Tuomas Tynkkynen 4ea9707591 libexpr: Fix prim_replaceStrings() to work on an empty source string
Otherwise, running e.g.

nix-instantiate --eval -E --strict 'builtins.replaceStrings [""] ["X"] "abc"'

would just hang in an infinite loop.

Found by afl-fuzz.
2018-02-19 23:20:26 +02:00
Shea Levy b095c06139
Add splitVersion primop.
Fixes #1868.
2018-02-14 09:55:43 -05:00
Shea Levy 48c192ca2d
builtins.path test: Don't rely on shlevy's XDG_RUNTIME_DIR 2018-02-07 10:26:53 -05:00
Shea Levy 69d82e5c58
Add path primop.
builtins.path allows specifying the name of a path (which makes paths
with store-illegal names now addable), allows adding paths with flat
instead of recursive hashes, allows specifying a filter (so is a
generalization of filterSource), and allows specifying an expected
hash (enabling safe path adding in pure mode).
2018-02-06 16:48:08 -05:00
Eelco Dolstra 2c39e4eca0
Revert "Don't parse "x:x" as a URI"
This reverts commit f90f660b24.

This broke Hydra's release.nix, which contained

  preCheck = ''export LOGNAME=${LOGNAME:-foo}'';
2017-11-14 15:10:52 +01:00
Eelco Dolstra f90f660b24
Don't parse "x:x" as a URI
URIs now have to contain "://" or start with "channel:".
2017-10-30 17:58:01 +01:00
Nicolas B. Pierron b8867a0239 Add builtins.string function.
The function 'builtins.split' takes a POSIX extended regular expression
and an arbitrary string. It returns a list of non-matching substring
interleaved by lists of matched groups of the regular expression.

```nix
with builtins;
assert split "(a)b" "abc"      == [ "" [ "a" ] "c" ];
assert split "([ac])" "abc"    == [ "" [ "a" ] "b" [ "c" ] "" ];
assert split "(a)|(c)" "abc"   == [ "" [ "a" null ] "b" [ null "c" ] "" ];
assert split "([[:upper:]]+)" "  FOO   "
                               == [ "  " [ "FOO" ] "   " ];
```
2017-08-15 20:04:11 +00:00
Graham Christensen 364f75e03a Update mailing list. 2017-07-18 08:04:01 -04:00
Eelco Dolstra f134fc4cbe
Document that builtins.match takes a POSIX extended RE 2017-05-17 12:18:18 +02:00
Guillaume Maudoux a474425425 Fix lexer to support $' in multiline strings. 2017-05-01 01:15:40 +02:00
Guillaume Maudoux e4b82af387 Improve error message on trailing path slashes 2016-11-27 17:48:46 +01:00
Guillaume Maudoux a5e761dddb Fix comments parsing
Fixed the parsing of multiline strings ending with an even number of
stars, like /** this **/.
Added test cases for comments.
2016-11-13 17:20:34 +01:00
Eelco Dolstra 26d92017d3 Add builtin function "partition"
The implementation of "partition" in Nixpkgs is O(n^2) (because of the
use of ++), and for some reason was causing stack overflows in
multi-threaded evaluation (not sure why).

This reduces "nix-env -qa --drv-path" runtime by 0.197s and memory
usage by 298 MiB (in non-Boehm mode).
2016-08-29 19:36:54 +02:00
Eelco Dolstra e03d6e0998 Fix broken number parsing in fromJSON
The call to tmp_number.append had its arguments mixed up. Also, JSON
does not allow a trailing "," after array/object members.
2016-02-15 15:01:26 +01:00
Eelco Dolstra eb62e23f14 Fix test broken by #762 2016-02-15 15:01:26 +01:00
Eelco Dolstra b3e8d72770 Merge pull request #762 from ctheune/ctheune-floats
Implement floats
2016-02-12 12:49:59 +01:00
Eelco Dolstra 4f7824c58e Remove tests/lexer.sh
"tests/lang.sh" can handle this.
2016-02-01 18:27:37 +01:00
Christian Theune 5cdcaf5e8e Adapt tests to show that floats work properly. 2016-01-06 10:03:24 +01:00
Eelco Dolstra 6f1743b1a5 Support SHA-512 hashes
Fixes #679.

Note: on x86_64, SHA-512 is considerably faster than SHA-256 (198 MB/s
versus 131 MB/s).
2015-11-04 16:37:49 +01:00
Eelco Dolstra 76cc8e97a2 Add sort primop 2015-07-28 18:39:39 +02:00
Eelco Dolstra 50807f3dd5 Add primop genList
This can be used to implement functions like ‘imap’ (or for that
matter, ‘map’) without the quadratic complexity incurred by calling
‘++’ repeatedly.
2015-07-28 17:28:35 +02:00
Eelco Dolstra d6d5885c15 Add replaceStrings primop
This is a generalisation of replaceChars in Nixpkgs.
2015-07-24 15:32:24 +02:00
Eelco Dolstra 2e8fd4c5cd Add concatStringsSep as a primop
This fixes the quadratic behaviour of concatStrings/concatStringsSep
in Nixpkgs.
2015-07-24 02:38:09 +02:00
Eelco Dolstra 14be783676 Add primops all and any
These are used thousands of times during NixOS evaluation, so it's
useful to speed them up.
2015-07-23 19:23:11 +02:00
Eelco Dolstra 61af14a921 Add foldl' primop 2015-07-23 17:03:02 +02:00
Guillaume Maudoux 467977f203 Fix the parsing of "$"'s in strings. 2015-07-03 14:09:58 +02:00
Shea Levy 73bf32ce94 Merge remote-tracking branch 'shlevy/baseNameOf-no-copy'
baseNameOf: Don't copy paths to the store first
2015-01-29 03:29:09 -05:00
Eelco Dolstra 976df480c9 Add a primop for regular expression pattern matching
The function ‘builtins.match’ takes a POSIX extended regular
expression and an arbitrary string. It returns ‘null’ if the string
does not match the regular expression. Otherwise, it returns a list
containing substring matches corresponding to parenthesis groups in
the regex. The regex must match the entire string (i.e. there is an
implied "^<pat>$" around the regex).  For example:

  match "foo" "foobar" => null
  match "foo" "foo" => []
  match "f(o+)(.*)" "foooobar" => ["oooo" "bar"]
  match "(.*/)?([^/]*)" "/dir/file.nix" => ["/dir/" "file.nix"]
  match "(.*/)?([^/]*)" "file.nix" => [null "file.nix"]

The following example finds all regular files with extension .nix or
.patch underneath the current directory:

  let

    findFiles = pat: dir: concatLists (mapAttrsToList (name: type:
      if type == "directory" then
        findFiles pat (dir + "/" + name)
      else if type == "regular" && match pat name != null then
        [(dir + "/" + name)]
      else []) (readDir dir));

  in findFiles ".*\\.(nix|patch)" (toString ./.)
2014-11-25 11:47:06 +01:00
Shea Levy 997defa166 Add functors (callable attribute sets).
With this, attribute sets with a `__functor` attribute can be applied
just like normal functions. This can be used to attach arbitrary
metadata to a function without callers needing to treat it specially.
2014-11-15 16:12:05 -05:00
Shea Levy c9bd6a1de4 Fix context test 2014-10-18 20:34:48 -04:00
Eelco Dolstra c3f0a489f9 Add primop ‘catAttrs’ 2014-10-04 18:15:03 +02:00
Eelco Dolstra d4fcbe1687 Add primop ‘attrValues’ 2014-10-04 16:41:24 +02:00
Shea Levy 3fd2d2187e Add test for readDir primop 2014-10-03 22:32:11 +02:00
Eelco Dolstra 0cd6596b0e Add ‘deepSeq’ primop
Note that unlike ‘lib.deepSeq’ in Nixpkgs, this handles cycles.
2014-09-22 16:05:00 +02:00
Eelco Dolstra a54c263402 Add ‘seq’ primop 2014-09-22 16:05:00 +02:00
Eelco Dolstra 3d221a7bb1 Rename nixPath to __nixPath
The name ‘nixPath’ breaks existing code.
2014-07-30 11:28:39 +02:00
Eelco Dolstra beaf3e90af Add builtin function ‘fromJSON’
Fixes #294.
2014-07-04 13:34:15 +02:00
Eelco Dolstra ee7fe64c0a == operator: Ignore string context
There really is no case I can think of where taking the context into
account is useful. Mostly it's just very inconvenient.
2014-06-10 14:02:56 +02:00
Eelco Dolstra ceed819284 Fix test 2014-05-29 19:04:27 +02:00
Eelco Dolstra 62a6eeb1f3 Make the Nix search path declarative
Nix search path lookups like <nixpkgs> are now desugared to ‘findFile
nixPath <nixpkgs>’, where ‘findFile’ is a new primop. Thus you can
override the search path simply by saying

  let
    nixPath = [ { prefix = "nixpkgs"; path = "/my-nixpkgs"; } ];
  in ... <nixpkgs> ...

In conjunction with ‘scopedImport’ (commit
c273c15cb1), the Nix search path can be
propagated across imports, e.g.

  let

    overrides = {
      nixPath = [ ... ] ++ builtins.nixPath;
      import = fn: scopedImport overrides fn;
      scopedImport = attrs: fn: scopedImport (overrides // attrs) fn;
      builtins = builtins // overrides;
    };

  in scopedImport overrides ./nixos
2014-05-26 17:02:22 +02:00
Eelco Dolstra 39d72640c2 Ensure that -I flags get included in nixPath
Also fixes #261.
2014-05-26 16:52:31 +02:00
Eelco Dolstra a8edf185a9 Add constant ‘nixPath’
It contains the Nix expression search path as a list of { prefix, path
} sets, e.g.

  [ { path = "/nix/var/nix/profiles/per-user/root/channels/nixos"; prefix = ""; }
    { path = "/etc/nixos/configuration.nix"; prefix = "nixos-config"; }
    { path = "/home/eelco/Dev/nix/inst/share/nix/corepkgs"; prefix = "nix"; }
  ]
2014-05-26 14:55:47 +02:00
Eelco Dolstra c273c15cb1 Add primop ‘scopedImport’
‘scopedImport’ works like ‘import’, except that it takes a set of
attributes to be added to the lexical scope of the expression,
essentially extending or overriding the builtin variables.  For
instance, the expression

  scopedImport { x = 1; } ./foo.nix

where foo.nix contains ‘x’, will evaluate to 1.

This has a few applications:

* It allows getting rid of function argument specifications in package
  expressions. For instance, a package expression like:

    { stdenv, fetchurl, libfoo }:

    stdenv.mkDerivation { ... buildInputs = [ libfoo ]; }

  can now we written as just

    stdenv.mkDerivation { ... buildInputs = [ libfoo ]; }

  and imported in all-packages.nix as:

    bar = scopedImport pkgs ./bar.nix;

  So whereas we once had dependencies listed in three places
  (buildInputs, the function, and the call site), they now only need
  to appear in one place.

* It allows overriding builtin functions. For instance, to trace all
  calls to ‘map’:

  let
    overrides = {
      map = f: xs: builtins.trace "map called!" (map f xs);

      # Ensure that our override gets propagated by calls to
      # import/scopedImport.
      import = fn: scopedImport overrides fn;

      scopedImport = attrs: fn: scopedImport (overrides // attrs) fn;

      # Also update ‘builtins’.
      builtins = builtins // overrides;
    };
  in scopedImport overrides ./bla.nix

* Similarly, it allows extending the set of builtin functions. For
  instance, during Nixpkgs/NixOS evaluation, the Nixpkgs library
  functions could be added to the default scope.

There is a downside: calls to scopedImport are not memoized, unlike
import. So importing a file multiple times leads to multiple parsings
/ evaluations. It would be possible to construct the AST only once,
but that would require careful handling of variables/environments.
2014-05-26 14:26:29 +02:00
Shea Levy 908e9ce259 If a dynamic attribute name evaluates to null, remove it from the set 2014-03-10 10:14:50 +01:00
Eelco Dolstra 5ad263c26b Test some more primops 2014-02-26 19:08:44 +01:00
Shea Levy f9913f4422 Allow "bare" dynamic attrs
Now, in addition to a."${b}".c, you can write a.${b}.c (applicable
wherever dynamic attributes are valid).

Signed-off-by: Shea Levy <shea@shealevy.com>
2014-01-14 14:00:15 +01:00
Eelco Dolstra 7a61c88dbb Merge branch 'dynamic-attrs-no-sugar' of github.com:shlevy/nix 2014-01-06 15:46:18 +01:00
Eelco Dolstra 4252b5a645 Disable the tail call test
On i686-linux, GCC stubbornly refuses to do tail-call optimisation.
Don't know why.

http://hydra.nixos.org/build/7300170
2014-01-06 11:32:22 +01:00
Shea Levy 6f3a51809a Fold dynamic binds handling into addAttr
Since addAttr has to iterate through the AttrPath we pass it, it makes
more sense to just iterate through the AttrNames in addAttr instead. As
an added bonus, this allows attrsets where two dynamic attribute paths
have the same static leading part (see added test case for an example
that failed previously).

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-12-31 17:57:10 -05:00
Shea Levy 18fefacf7d Dynamic attrs
This adds new syntax for attribute names:

* attrs."${name}" => getAttr name attrs
* attrs ? "${name}" => isAttrs attrs && hasAttr attrs name
* attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def
* { "${name}" = value; } => listToAttrs [{ inherit name value; }]

Of course, it's a bit more complicated than that. The attribute chains
can be arbitrarily long and contain combinations of static and dynamic
parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively
straightforward for the getAttrs/hasAttrs cases but is more complex for
the listToAttrs case due to rules about duplicate attribute definitions.

For attribute sets with dynamic attribute names, duplicate static
attributes are detected at parse time while duplicate dynamic attributes
are detected when the attribute set is forced. So, for example, { a =
null; a.b = null; "${"c"}" = true; } will be a parse-time error, while
{ a = {}; "${"a"}".b = null; c = true; } will be an eval-time error
(technically that case could theoretically be detected at parse time,
but the general case would require full evaluation). Moreover, duplicate
dynamic attributes are not allowed even in cases where they would be
with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but {
a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction
might be relaxed in the future in cases where the static variant would
not be an error, but it is not obvious that that is desirable.

Finally, recursive attribute sets with dynamic attributes have the
static attributes in scope but not the dynamic ones. So rec { a = true;
"${"b"}" = a; } is equivalent to { a = true; b = true; } but rec {
"${"a"}" = true; b = a; } would be an error or use a from the
surrounding scope if it exists.

Note that the getAttr, getAttr or default, and hasAttr are all
implemented purely in the parser as syntactic sugar, while attribute
sets with dynamic attribute names required changes to the AST to be
implemented cleanly.

This is an alternative solution to and closes #167

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-12-31 20:59:49 +00:00
Shea Levy 136f2f7046 Add the ExprBuiltin Expr type to the AST
Certain desugaring schemes may require the parser to use some builtin
function to do some of the work (e.g. currently `throw` is used to
lazily cause an error if a `<>`-style path is not in the search path)
Unfortunately, these names are not reserved keywords, so an expression
that uses such a syntactic sugar will not see the expected behavior
(see tests/lang/eval-okay-redefine-builtin.nix for an example).

This adds the ExprBuiltin AST type, which when evaluated uses the value
from the rootmost variable scope (which of course is initialized
internally and can't shadow any of the builtins).

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-12-31 17:45:47 +00:00
Eelco Dolstra 77c13cdf56 Add a toJSON primop 2013-11-19 00:04:11 +01:00
Eelco Dolstra 285df765b9 Add a primop unsafeGetAttrPos to return the position of an attribute 2013-11-18 22:22:35 +01:00
Eelco Dolstra fc33fd86b7 Add a symbol __curPos that expands to the current source location
I.e. an attribute set { file = <string>; line = <int>; column = <int>; }.
2013-11-18 20:16:02 +01:00
Eelco Dolstra 2bcb384e95 Add a test to check that tail calls run in bounded stack space 2013-11-12 12:34:22 +01:00
Eelco Dolstra 5bc41d78ff Rename "attribute sets" to "sets"
We don't have any other kind of sets so calling them attribute sets is
unnecessarily verbose.
2013-10-24 16:41:04 +02:00
Eelco Dolstra 411a3461dc Add a test of the type primops 2013-10-24 02:51:28 +02:00
Eelco Dolstra 9d8a80375d Add a test for type correctness of antiquotes
Antiquotes should evaluate to strings or paths.  This is usually
checked, except in the case where the antiquote makes up the entire
string, as in "${expr}".  This is optimised to expr, which discards
the runtime type checks / coercions.
2013-10-17 00:51:07 +02:00
Eelco Dolstra b8571d68c4 Add a regression test for correct path antiquotation behavior
This broke in Nix 1.6.
2013-10-16 23:29:11 +02:00
Shea Levy afc6c1bad6 Simplify inherited attribute handling
This reduces the difference between inherited and non-inherited
attribute handling to the choice of which env to use (in recs and lets)
by setting the AttrDef::e to a new ExprVar in the parser rather than
carrying a separate AttrDef::v VarRef member.

As an added bonus, this allows inherited attributes that inherit from a
with to delay forcing evaluation of the with's attributes.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-08-26 11:31:56 +02:00
Ivan Kozik 34bb806f74 Fix typos, especially those that end up in the Nix manual 2013-08-26 11:15:22 +02:00
Eelco Dolstra 8e74c0bfd1 Let the ordering operators also work on strings
E.g. ‘"foo" < "bar"’ now works.
2013-08-02 18:53:02 +02:00
Eelco Dolstra 3d77b28eac Add comparison operators ‘<’, ‘<=’, ‘>’ and ‘>=’ 2013-08-02 18:39:40 +02:00
Eelco Dolstra 47701677e8 Add integer ‘-’, ‘*’ and ‘/’ operators 2013-08-02 16:03:02 +00:00
Eelco Dolstra 5d147e125c Add a unary integer negation operator
This allows saying "-1" instead of "builtins.sub 0 1".
2013-08-02 15:43:31 +00:00
Eelco Dolstra 159e621d1a Overload the ‘+’ operator to support integer addition 2013-08-02 15:21:17 +00:00
Eelco Dolstra 7df4ef983e Test the delayed with a bit more 2013-07-31 13:12:35 +02:00
Shea Levy 20866a7031 Delay evaulation of with attrs until a variable lookup needs them
Evaluation of attribute sets is strict in the attribute names, which
means immediate evaluation of `with` attribute sets rules out some
potentially interesting use cases (e.g. where the attribute names of one
set depend in some way on another but we want to bring those names into
scope for some values in the second set).

The major example of this is overridable self-referential package sets
(e.g. all-packages.nix). With immediate `with` evaluation, the only
options for such sets are to either make them non-recursive and
explicitly use the name of the overridden set in non-overridden one
every time you want to reference another package, or make the set
recursive and use the `__overrides` hack. As shown in the test case that
comes with this commit, though, delayed `with` evaluation allows a nicer
third alternative.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-31 11:48:39 +02:00
Eelco Dolstra 52172607cf Rename "hash" to "hashString" and handle SHA-1 2013-02-08 19:36:23 +01:00
Marc Weber 01a5ea9914 experimental/hash
adding primop function calculating hash of a string

Signed-off-by: Marc Weber <marco-oweber@gmx.de>
2013-02-08 19:26:34 +01:00
Eelco Dolstra 95c74eae26 Allow dashes in identifiers
In Nixpkgs, the attribute in all-packages.nix corresponding to a
package is usually equal to the package name.  However, this doesn't
work if the package contains a dash, which is fairly common.  The
convention is to replace the dash with an underscore (e.g. "dbus-lib"
becomes "dbus_glib"), but that's annoying.  So now dashes are valid in
variable / attribute names, allowing you to write:

  dbus-glib = callPackage ../development/libraries/dbus-glib { };

and

  buildInputs = [ dbus-glib ];

Since we don't have a negation or subtraction operation in Nix, this
is unambiguous.
2012-09-27 15:49:20 -04:00
Eelco Dolstra 126c7317bc * Add a test case for comparing derivations. 2012-01-19 22:10:24 +00:00
Eelco Dolstra 48cea0d01e * Refactoring: Get rid of a few subdirectories in corepkgs/, and some
other simplifications.
* Use <nix/...> to locate the corepkgs.  This allows them to be
  overriden through $NIX_PATH.
* Use bash's pipefail option in the NAR builder so that we don't need
  to create a temporary file.
2012-01-03 00:16:29 +00:00
Eelco Dolstra 3877619888 * Add some accidentally committed files. 2011-12-21 11:47:52 +00:00