From 040140dd1c3c11e3aa1ca486c3f3596cbe99c008 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 18 May 2005 17:19:21 +0000 Subject: [PATCH] * Added a primop `removeAttrs' to remove attributes from a set, e.g., `removeAttrs attrs ["x", "y"]' returns the set `attrs' with the attributes named `x' and `y' removed. It is not an error for the named attributes to be missing from the input set. --- src/libexpr/primops.cc | 18 ++++++++++++++++++ tests/lang/eval-fail-remove.nix | 5 +++++ tests/lang/eval-okay-remove.exp | 1 + tests/lang/eval-okay-remove.nix | 5 +++++ 4 files changed, 29 insertions(+) create mode 100644 tests/lang/eval-fail-remove.nix create mode 100644 tests/lang/eval-okay-remove.exp create mode 100644 tests/lang/eval-okay-remove.nix diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index e3dd2db18..b0986028e 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 000000000..539e0eb0a --- /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 000000000..e22e6b1b2 --- /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 000000000..4ad5ba897 --- /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