Merge pull request #168 from Flipez/while-break-support

[evaluator/while]: Add support for `break`

docs/docs/control_expressions/while.md

@@ -23,3 +23,26 @@ end
 3
 => nil
 ```
+
+It is possible to use `next` or `break` inside a while loop.
+
+```js
+i = 0
+while (i < 10)
+  if (i < 3)
+    i = i + 1
+    next
+  end
+  puts(i)
+  if (i == 6)
+    break
+  end
+  i = i + 1
+end
+
+// which prints
+3
+4
+5
+6
+```

evaluator/while.go

@@ -14,6 +14,11 @@ func evalWhile(w *ast.While, env *object.Environment) object.Object {
 		if rt != nil && (rt.Type() == object.RETURN_VALUE_OBJ || rt.Type() == object.ERROR_OBJ) {
 			return rt
 		}
+
+		if rt != nil && rt.Type() == object.BREAK_VALUE_OBJ {
+			return rt.(*object.BreakValue).Value
+		}
+
 		v = Eval(w.Condition, env)
 	}
 

tests/while.expected

@@ -3,5 +3,9 @@
 2
 0
 1
+3
+4
+5
+6
 0
 ERROR: division by zero not allowed

tests/while.rl

@@ -17,6 +17,21 @@ def test_one()
 end
 
 def test_two()
+  i = 0
+  while (i < 10)
+    if (i < 3)
+      i = i + 1
+      next
+    end
+    puts(i)
+    if (i == 6)
+      break
+    end
+    i = i + 1
+  end
+end
+
+def test_three()
   a = 0
   while (a != 3)
     puts(a)
@@ -25,4 +40,5 @@ def test_two()
 end
 
 test_one()
-test_two()
+test_two()
+test_three()