From 040140dd1c3c11e3aa1ca486c3f3596cbe99c008 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 18 May 2005 17:19:21 +0000 Subject: * 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 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'src/libexpr/primops.cc') diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index e3dd2db18d83..b0986028ee24 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); } -- cgit 1.4.1