Do not throw an exception when a when-statement with no else makes no match

2013-10-18 18:34:54 +04:00
parent aacf133ef6
commit ea2b6e4546
10 changed files with 111 additions and 2 deletions
@@ -3725,7 +3725,17 @@ The "returned" value of try expression with no finally is either the last expres
        }
        if (!hasElse && nextCondition != null) {
            v.mark(nextCondition);
-            throwNewException(CLASS_NO_PATTERN_MATCHED_EXCEPTION);
+            if (!isStatement) {
+                // a result is expected
+                if (Boolean.TRUE.equals(bindingContext.get(BindingContext.EXHAUSTIVE_WHEN, expression))) {
+                    // when() is supposed to be exhaustive
+                    throwNewException(CLASS_NO_PATTERN_MATCHED_EXCEPTION);
+                }
+                else {
+                    // non-exhaustive when() with no else -> Unit must be expected
+                    StackValue.putUnitInstance(v);
+                }
+            }
        }

        markLineNumber(expression);