mirror of
https://github.com/privatevoid-net/nix-super.git
synced 2024-11-25 15:26:17 +02:00
Add primop ‘catAttrs’
This commit is contained in:
parent
d4fcbe1687
commit
c3f0a489f9
3 changed files with 32 additions and 0 deletions
|
@ -1123,6 +1123,35 @@ static void prim_intersectAttrs(EvalState & state, const Pos & pos, Value * * ar
|
|||
}
|
||||
|
||||
|
||||
/* Collect each attribute named `attr' from a list of attribute sets.
|
||||
Sets that don't contain the named attribute are ignored.
|
||||
|
||||
Example:
|
||||
catAttrs "a" [{a = 1;} {b = 0;} {a = 2;}]
|
||||
=> [1 2]
|
||||
*/
|
||||
static void prim_catAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
|
||||
{
|
||||
Symbol attrName = state.symbols.create(state.forceStringNoCtx(*args[0], pos));
|
||||
state.forceList(*args[1], pos);
|
||||
|
||||
Value * res[args[1]->list.length];
|
||||
unsigned int found = 0;
|
||||
|
||||
for (unsigned int n = 0; n < args[1]->list.length; ++n) {
|
||||
Value & v2(*args[1]->list.elems[n]);
|
||||
state.forceAttrs(v2, pos);
|
||||
Bindings::iterator i = v2.attrs->find(attrName);
|
||||
if (i != v2.attrs->end())
|
||||
res[found++] = i->value;
|
||||
}
|
||||
|
||||
state.mkList(v, found);
|
||||
for (unsigned int n = 0; n < found; ++n)
|
||||
v.list.elems[n] = res[n];
|
||||
}
|
||||
|
||||
|
||||
/* Return a set containing the names of the formal arguments expected
|
||||
by the function `f'. The value of each attribute is a Boolean
|
||||
denoting whether has a default value. For instance,
|
||||
|
@ -1530,6 +1559,7 @@ void EvalState::createBaseEnv()
|
|||
addPrimOp("removeAttrs", 2, prim_removeAttrs);
|
||||
addPrimOp("__listToAttrs", 1, prim_listToAttrs);
|
||||
addPrimOp("__intersectAttrs", 2, prim_intersectAttrs);
|
||||
addPrimOp("__catAttrs", 2, prim_catAttrs);
|
||||
addPrimOp("__functionArgs", 1, prim_functionArgs);
|
||||
|
||||
// Lists
|
||||
|
|
1
tests/lang/eval-okay-catattrs.exp
Normal file
1
tests/lang/eval-okay-catattrs.exp
Normal file
|
@ -0,0 +1 @@
|
|||
[ 1 2 ]
|
1
tests/lang/eval-okay-catattrs.nix
Normal file
1
tests/lang/eval-okay-catattrs.nix
Normal file
|
@ -0,0 +1 @@
|
|||
builtins.catAttrs "a" [ { a = 1; } { b = 0; } { a = 2; } ]
|
Loading…
Reference in a new issue