iter semantics: always sets iter var to nowhere if False is returned

libwccl/ops/functions/bool/iteration.cpp

@@ -25,11 +25,8 @@ std::ostream& Iteration::write_to(std::ostream& os) const
 
 Iteration::BaseRetValPtr Iteration::apply_internal(const FunExecContext& context) const
 {
-	// Set iteration variable to Nowhere
-	// Should be overridden if succeeded
 	const boost::shared_ptr<Position>& iter_var =
 		context.variables()->get_fast(iter_var_acc_);
-	iter_var->set_value(Position::Nowhere);
 	const SentenceContext& sc = context.sentence_context();
 	// Proceed only if range extremes are not "nowhere".
 	const boost::shared_ptr<const Position>& range_left =
@@ -48,7 +45,7 @@ Iteration::BaseRetValPtr Iteration::apply_internal(const FunExecContext& context
 			}
 		}
 	}
-	// Failure. Make sure iteration variable points Nowhere and return False
+	// Failure. Set iteration variable to Nowhere and return False
 	iter_var->set_value(Position::Nowhere);
 	return Predicate::False(context);
 }

tests/data/crossing.ccl

@@ -36,3 +36,58 @@ only(1, 0, $It, False)
 True
 It=nowhere
 ---
+and(setvar($It,2), rlook(0, 1, $It, True))
+
+True
+It=0
+---
+and(setvar($It,2), llook(1, 0, $It, True))
+
+True
+It=1
+---
+and(setvar($It,2), rlook(1, 0, $It, True))
+
+False
+It=nowhere
+---
+and(setvar($It,2), llook(0, 1, $It, True))
+
+False
+It=nowhere
+---
+and(setvar($It,2), only(0, 1, $It, True))
+
+True
+It=1
+---
+and(setvar($It,2), only(1, 0, $It, True))
+
+True
+It=2
+---
+and(setvar($It,2), only(1, 0, $It, False))
+
+True
+It=2
+---
+and(setvar($It,2), only(0, 1, $It, False))
+
+False
+It=nowhere
+---
+and(setvar($It,6), atleast(0, 3, $It, inside($It), 2))
+
+True
+It=1
+---
+and(setvar($It,6), atleast(3, 0, $It, inside($It), 2))
+
+False
+It=nowhere
+---
+and(setvar($It,6), atleast(0, 3, $It, inside($It), 7))
+
+False
+It=nowhere
+---