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.
* src/libexpr/expr-to-xml.cc (nix::showAttrs): Add `location'
parameter. Provide location XML attributes when it's true. Update
callers.
(nix::printTermAsXML): Likewise.
* src/libexpr/expr-to-xml.hh (nix::printTermAsXML): Update prototype;
have `location' default to `false'.
* src/nix-instantiate/nix-instantiate.cc (printResult, processExpr): Add
`location' parameter; update callers.
(run): Add support for `--no-location'.
* src/nix-instantiate/help.txt: Update accordingly.
* tests/lang.sh: Invoke `nix-instantiate' with `--no-location' for the
XML tests.
* tests/lang/eval-okay-toxml.exp, tests/lang/eval-okay-to-xml.nix: New
files.
`nix-store --delete'. But unprivileged users are not allowed to
ignore liveness.
* `nix-store --delete --ignore-liveness': ignore the runtime roots as
well.
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.
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'.)
derivation(s) we're interested, e.g.,
$ nix-instantiate ./all-packages.nix --attr xlibs.libX11
List elements can also be selected:
$ nix-instantiate ./build-for-release.nix --attr 0.subversion
This allows a non-ambiguous specification of a derivation. Of
course, this should also be added to nix-env and nix-build.
with default values automatically. I.e., e -> e {}.
This feature makes convenience expressions such as
pkgs/system/i686-linux.nix in Nixpkgs obsolete, since we can just do
$ nix-instantiate ./pkgs/system/all-packages.nix
since all-packages.nix takes a single argument (system) that has a
default value (__thisSystem).
get rid of GC roots. Nix-build places a symlink `result' in the
current directory. Previously, removing that symlink would not
remove the store path being linked to as a GC root. Now, the GC
root created by nix-build is actually a symlink in
`/nix/var/nix/gcroots/auto' to `result'. So if that symlink is
removed the GC root automatically becomes invalid (since it can no
longer be resolved). The root itself is not automatically removed -
the garbage collector should delete dangling roots.
