Attach (optional) labels to blocks rather than loops

This makes it possible to return values from any block by breaking out
of it, enabling if statements to yield expressions when combined with
commit ce68792c848caee2f184e7a6392d9f1e958da1a1.

2 files changed, 4 insertions, 4 deletions

diff --git a/doc/grammar.txt b/doc/grammar.txt
index 4df88d7..0a86a68 100644
--- a/doc/grammar.txt
+++ b/doc/grammar.txt
@@ -14,7 +14,7 @@ externfunc := "extern" "func" NAME "(" ( type ), ")" [ type ] ";"
 constant := [ COMMENT ]
 		"const" NAME "=" ( NUMBER | bool | STRING* | type ) ";"
 
-block := "{" command* "}"
+block := [ ":" NAME ] "{" command* "}"
 
 command := block | statement
 
@@ -30,11 +30,11 @@ if := "if" expression block elseif* else*
 elseif := "else" "if" expression block
 else := "else" block
 
-for := "for" [ ":" NAME ] [ assignment ";" ] expression [ ";" assignment ] block
+for := "for" [ assignment ";" ] expression [ ";" assignment ] block
 
 return := "return" expression
 
-break := "break" ":" NAME
+break := "break" ":" NAME [ expression ]
 continue := "continue" ":" NAME
 
 declaration := "let" [ "mut" ] NAME "=" expression ";"
diff --git a/include/parse.h b/include/parse.h
index ff5e3f1..21584cc 100644
--- a/include/parse.h
+++ b/include/parse.h
@@ -19,6 +19,7 @@ struct ast_param {
 };
 
 struct ast_block {
+	const char *label;
 	struct ast_cmd *cmds;
 	int cmdsz, cmdlen;
 };
@@ -92,7 +93,6 @@ struct ast_if {
 };
 
 struct ast_for {
-	const char *label;
 	struct ast_assign *init, *action;
 	struct ast_expr cond;
 	struct ast_block blk;