block labels

compiler/parser/parser.odin

@@ -1036,10 +1036,20 @@ parse_yield :: proc(parser: ^Parser) -> ast.Stmt_Id {
 // checker rejects them outside a loop.
 parse_loop_control :: proc(parser: ^Parser, kind: ast.Stmt_Kind) -> ast.Stmt_Id {
 	marker := advance(parser) // consume 'break' / 'continue'
+	// `break :outer` / `continue :outer` targets the enclosing loop labeled `outer`.
+	label := symbol.INVALID
+	if _, ok := allow(parser, .Colon); ok {
+		if name, name_ok := allow(parser, .Identifier); name_ok {
+			label = name.symbol
+		} else {
+			source.add(parser.diagnostics, current(parser).span, "expected a loop label after ':'")
+		}
+	}
 	id := ast.stmt_id(len(parser.module.statements))
 	append(&parser.module.statements, ast.Stmt{
 		kind=kind,
 		span=marker.span,
+		label=label,
 		expr=ast.INVALID_EXPR,
 		update=ast.INVALID_STMT,
 		diagnostic=source.INVALID_DIAGNOSTIC,
@@ -1169,6 +1179,26 @@ parse_statement :: proc(parser: ^Parser) -> ast.Stmt_Id {
 				kind = .Declaration
 				immutable = operator.kind == .Colon_Colon
 			}
+			// A labeled value block (`x :: blk: { … yield :blk v }`): the label lets a
+			// `yield :blk` exit the block past a nested `if`. Block-init body + label.
+			if current(parser).kind == .Identifier && peek(parser).kind == .Colon {
+				label := parse_optional_loop_label(parser)
+				body := parse_block(parser)
+				id := ast.stmt_id(len(parser.module.statements))
+				append(&parser.module.statements, ast.Stmt{
+					kind=kind,
+					span=span_from(name.span, previous(parser).span),
+					name=name.symbol,
+					type=type_syntax,
+					immutable=immutable,
+					label=label,
+					target=ast.INVALID_EXPR,
+					expr=ast.INVALID_EXPR,
+					body=body,
+					diagnostic=source.INVALID_DIAGNOSTIC,
+				})
+				return id
+			}
 			// A `{` on the right is a value block: parse its statements now; the
 			// checker turns its final `yield` into the declared/assigned value.
 			if current(parser).kind == .Left_Brace {
@@ -1227,6 +1257,22 @@ parse_statement :: proc(parser: ^Parser) -> ast.Stmt_Id {
 	expr := parse_expression(parser)
 	if _, ok := allow(parser, .Equal); ok {
 		skip_newlines(parser)
+		// A labeled value block assigned to a complex target (`a[i] = blk: { … }`).
+		if current(parser).kind == .Identifier && peek(parser).kind == .Colon {
+			label := parse_optional_loop_label(parser)
+			body := parse_block(parser)
+			id := ast.stmt_id(len(parser.module.statements))
+			append(&parser.module.statements, ast.Stmt{
+				kind=.Assignment,
+				span=span_from(parser.module.exprs[expr].span, previous(parser).span),
+				target=expr,
+				label=label,
+				expr=ast.INVALID_EXPR,
+				body=body,
+				diagnostic=source.INVALID_DIAGNOSTIC,
+			})
+			return id
+		}
 		// A value block assigned to a complex target (`a[i] = { ... }`, `p.f = { ... }`).
 		if current(parser).kind == .Left_Brace {
 			brace := current(parser)