Age | Commit message (Collapse) | Author | Files | Lines |
|
|
|
[1 2 3] ++ [4 5 6] => [1 2 3 4 5 6]
|
|
|
|
|
|
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.
|
|
|
|
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.
|
|
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.
|
|
`attrs ? x' yields true iff `attrs' has an attribute named `x'.
|
|
{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'.
|
|
`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];
...
|
|
b then x else y.z'.
|
|
other attribute sets, rather than the current scope. E.g.,
{inherit (pkgs) gcc binutils;}
is equivalent to
{gcc = pkgs.gcc; binutils = pkgs.binutils;}
I am not so happy about the syntax.
|
|
{x=1; y=2; z=3;} // {y=4;} => {x=1; y=4; z=3;}
|
|
`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}'.
|
|
* Include missing files in distributions.
|
|
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.
|