wroclaw-git-backups/nix
1
0
Fork 0
mirror of https://github.com/NixOS/nix synced 2025-06-25 14:51:16 +02:00
Code Activity

Work on Values instead of Exprs

Browse source 
This prevents some duplicate evaluation in nix-env and
nix-instantiate.

Also, when traversing ~/.nix-defexpr, only read regular files with the
extension .nix.  Previously it was reading files like
.../channels/binary-caches/<name>.  The only reason this didn't cause
problems is pure luck (namely, <name> shadows an actual Nix
expression, the binary-caches files happen to be syntactically valid
Nix expressions, and we iterate over the directory contents in just
the right order).
This commit is contained in:
Eelco Dolstra 2013-09-03 13:17:51 +00:00
parent 06bb2d95b4
commit ef4f5ba85e
4 changed files with 62 additions and 50 deletions
Download patch file Download diff file Expand all files Collapse all files

35
src/libexpr/attr-path.cc
View file

@ -6,9 +6,8 @@
namespace nix {
// !!! Shouldn't we return a pointer to a Value?
void findAlongAttrPath(EvalState & state, const string & attrPath,
Bindings & autoArgs, Expr * e, Value & v)
Value * findAlongAttrPath(EvalState & state, const string & attrPath,
Bindings & autoArgs, Value & vIn)
{
Strings tokens = tokenizeString<Strings>(attrPath, ".");
@ -17,7 +16,7 @@ void findAlongAttrPath(EvalState & state, const string & attrPath,
string curPath;
state.mkThunk_(v, e);
Value * v = &vIn;
foreach (Strings::iterator, i, tokens) {
@ -31,10 +30,10 @@ void findAlongAttrPath(EvalState & state, const string & attrPath,
if (string2Int(attr, attrIndex)) apType = apIndex;
/* Evaluate the expression. */
Value vTmp;
state.autoCallFunction(autoArgs, v, vTmp);
v = vTmp;
state.forceValue(v);
Value * vNew = state.allocValue();
state.autoCallFunction(autoArgs, *v, *vNew);
v = vNew;
state.forceValue(*v);
/* It should evaluate to either an attribute set or an
expression, according to what is specified in the
@ -42,31 +41,33 @@ void findAlongAttrPath(EvalState & state, const string & attrPath,
if (apType == apAttr) {
if (v.type != tAttrs)
if (v->type != tAttrs)
throw TypeError(
format("the expression selected by the selection path `%1%' should be an attribute set but is %2%")
% curPath % showType(v));
% curPath % showType(*v));
Bindings::iterator a = v.attrs->find(state.symbols.create(attr));
if (a == v.attrs->end())
Bindings::iterator a = v->attrs->find(state.symbols.create(attr));
if (a == v->attrs->end())
throw Error(format("attribute `%1%' in selection path `%2%' not found") % attr % curPath);
v = *a->value;
v = &*a->value;
}
else if (apType == apIndex) {
if (v.type != tList)
if (v->type != tList)
throw TypeError(
format("the expression selected by the selection path `%1%' should be a list but is %2%")
% curPath % showType(v));
% curPath % showType(*v));
if (attrIndex >= v.list.length)
if (attrIndex >= v->list.length)
throw Error(format("list index %1% in selection path `%2%' is out of range") % attrIndex % curPath);
v = *v.list.elems[attrIndex];
v = v->list.elems[attrIndex];
}
}
return v;
}