Merge pull request #145 from Vardan2009/master

Added `fallout` statement

core/interpreter.py

@@ -797,6 +797,7 @@ def visit_SwitchNode(self, node: SwitchNode, context: Context) -> RTResult[Value
         assert subject is not None
 
         should_continue = False
+        fallout = False
         for expr, body in node.cases:
             if not should_continue:
                 value = res.register(self.visit(expr, context))
@@ -814,6 +815,14 @@ def visit_SwitchNode(self, node: SwitchNode, context: Context) -> RTResult[Value
                 if res.should_return():
                     return res
 
+                if res.should_fallout:
+                    should_continue = True
+                    fallout = True
+                    continue
+
+                if fallout:
+                    continue
+
                 if res.should_fallthrough:
                     should_continue = True
                     continue
@@ -830,6 +839,9 @@ def visit_SwitchNode(self, node: SwitchNode, context: Context) -> RTResult[Value
     def visit_FallthroughNode(self, node: FallthroughNode, context: Context) -> RTResult[Value]:
         return RTResult[Value]().success(Null.null()).fallthrough()
 
+    def visit_FalloutNode(self, node: FalloutNode, context: Context) -> RTResult[Value]:
+        return RTResult[Value]().success(Null.null()).fallout()
+
     def visit_AttrAccessNode(self, node: AttrAccessNode, context: Context) -> RTResult[Value]:
         res = RTResult[Value]()
         value = res.register(self.visit(node.node_to_access, context))

core/nodes.py

@@ -313,6 +313,12 @@ class FallthroughNode:
     pos_end: Position
 
 
+@dataclass
+class FalloutNode:
+    pos_start: Position
+    pos_end: Position
+
+
 @dataclass
 class TryNode:
     try_block: Node

core/parser.py

@@ -171,6 +171,18 @@ def statement(self) -> ParseResult[Optional[Node]] | ParseResult[Node]:
                 return res.success(UnitRaiseNode(call, call.pos_start, call.pos_end))
             return res.success(RaiseNode(call, call.pos_start, call.pos_end))
 
+        if self.current_tok.matches(TT_KEYWORD, "fallout"):
+            if not self.in_case:
+                return res.failure(
+                    InvalidSyntaxError(
+                        self.current_tok.pos_start,
+                        self.current_tok.pos_end,
+                        "Fallout statement must be inside a switch-case statement",
+                    )
+                )
+            self.advance(res)
+            return res.success(FalloutNode(pos_start, self.current_tok.pos_start.copy()))
+
         if self.current_tok.matches(TT_KEYWORD, "return"):
             if not self.in_func:
                 return res.failure(
@@ -1501,6 +1513,7 @@ class RTResult(Generic[T]):
     loop_should_break: bool
     should_exit: bool
     should_fallthrough: bool
+    should_fallout: bool
 
     def __init__(self) -> None:
         self.reset()
@@ -1513,6 +1526,7 @@ def reset(self) -> None:
         self.loop_should_break = False
         self.should_exit = False
         self.should_fallthrough = False
+        self.should_fallout = False
 
     U = TypeVar("U")
 
@@ -1523,6 +1537,7 @@ def register(self, res: RTResult[U]) -> Optional[U]:
         self.loop_should_break = res.loop_should_break
         self.should_exit = res.should_exit
         self.should_fallthrough = res.should_fallthrough
+        self.should_fallout = res.should_fallout
         return res.value
 
     def success(self, value: T) -> RTResult[T]:
@@ -1559,6 +1574,10 @@ def fallthrough(self) -> RTResult[T]:
         self.should_fallthrough = True
         return self
 
+    def fallout(self) -> RTResult[T]:
+        self.should_fallout = True
+        return self
+
     def failure(self, error: Error) -> RTResult[T]:
         self.reset()
         self.error = error

core/tokens.py

@@ -133,6 +133,7 @@ def copy(self) -> Position:
     "default",
     "fallthrough",
     "raise",
+    "fallout",
 ]
 
 TokenValue: TypeAlias = Optional[str | int | float]

tests/fallout.rn

@@ -0,0 +1,10 @@
+switch 44 {
+    case 42 -> print("42")
+    case 43 -> print("43")
+    case 44 -> fallout
+    case 45 -> print("45")
+    case 46 -> print("46")
+    case 47 -> print("47")
+    case 48 -> print("48")
+    default -> print("default")
+}

tests/fallout.rn.json

@@ -0,0 +1 @@
+{"code": 0, "stdout": "45\n46\n47\n48\ndefault\n", "stderr": ""}