forked from lix-project/lix
77557a6f06
* 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).
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||
|---|---|---|
| .. | ||
| eval.cc | ||
| eval.hh | ||
| lexer.l | ||
| Makefile.am | ||
| nixexpr-ast.def | ||
| nixexpr.cc | ||
| nixexpr.hh | ||
| parser.cc | ||
| parser.hh | ||
| parser.y | ||
| primops.cc | ||