diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index e3dd2db18d..b0986028ee 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -444,6 +444,23 @@ static Expr primCurrentTime(EvalState & state, const ATermVector & args) } +static Expr primRemoveAttrs(EvalState & state, const ATermVector & args) +{ + ATermMap attrs; + queryAllAttrs(evalExpr(state, args[0]), attrs, true); + + ATermList list; + if (!matchList(evalExpr(state, args[1]), list)) + throw Error("`removeAttrs' expects a list as its second argument"); + + for (ATermIterator i(list); i; ++i) + /* It's not an error for *i not to exist. */ + attrs.remove(evalString(state, *i)); + + return makeAttrs(attrs); +} + + void EvalState::addPrimOps() { addPrimOp("true", 0, primTrue); @@ -460,6 +477,7 @@ void EvalState::addPrimOps() addPrimOp("isNull", 1, primIsNull); addPrimOp("map", 2, primMap); + addPrimOp("removeAttrs", 2, primRemoveAttrs); } diff --git a/tests/lang/eval-fail-remove.nix b/tests/lang/eval-fail-remove.nix new file mode 100644 index 0000000000..539e0eb0a6 --- /dev/null +++ b/tests/lang/eval-fail-remove.nix @@ -0,0 +1,5 @@ +let { + attrs = {x = 123; y = 456;}; + + body = (removeAttrs attrs ["x"]).x; +} \ No newline at end of file diff --git a/tests/lang/eval-okay-remove.exp b/tests/lang/eval-okay-remove.exp new file mode 100644 index 0000000000..e22e6b1b21 --- /dev/null +++ b/tests/lang/eval-okay-remove.exp @@ -0,0 +1 @@ +Int(456) diff --git a/tests/lang/eval-okay-remove.nix b/tests/lang/eval-okay-remove.nix new file mode 100644 index 0000000000..4ad5ba897f --- /dev/null +++ b/tests/lang/eval-okay-remove.nix @@ -0,0 +1,5 @@ +let { + attrs = {x = 123; y = 456;}; + + body = (removeAttrs attrs ["x"]).y; +} \ No newline at end of file