feat: Loop labels

closes #199

CHANGELOG.md

@@ -50,6 +50,7 @@ var value = from {
 - Tracing JIT (https://github.com/buzz-language/buzz/issues/134): will look for hot loops and compile them
 - `list.fill`
 - `std.panic` will panic and print current stack trace
+- Loop can have _labels_ that you can `break` or `continue` to (https://github.com/buzz-language/buzz/issues/199)
 
 ## Changed
 - Map type notation has changed from `{K, V}` to `{K: V}`. Similarly map expression with specified typed went from `{<K, V>, ...}` to `{<K: V>, ...}` (https://github.com/buzz-language/buzz/issues/253)

src/Ast.zig

@@ -157,9 +157,9 @@ pub const Node = struct {
         Block: []Node.Index,
         BlockExpression: []Node.Index,
         Boolean: bool,
-        Break: void,
+        Break: ?Node.Index,
         Call: Call,
-        Continue: void,
+        Continue: ?Node.Index,
         Dot: Dot,
         DoUntil: WhileDoUntil,
         Enum: Enum,
@@ -458,6 +458,7 @@ pub const For = struct {
     condition: Node.Index,
     post_loop: []Node.Index,
     body: Node.Index,
+    label: ?TokenIndex,
 };
 
 pub const ForEach = struct {
@@ -466,6 +467,7 @@ pub const ForEach = struct {
     value: Node.Index,
     body: Node.Index,
     key_omitted: bool,
+    label: ?TokenIndex,
 };
 
 pub const Function = struct {
@@ -697,6 +699,7 @@ pub const VarDeclaration = struct {
 pub const WhileDoUntil = struct {
     condition: Node.Index,
     body: Node.Index,
+    label: ?TokenIndex,
 };
 
 pub const Zdef = struct {