feat(compiler): Allow non-block bodies with loops (#2064)

Author: alex-snezhko

compiler/src/parsing/parser.messages

@@ -532,9 +532,6 @@ braced_expr:
   | lbrace block_body rbrace { Expression.block ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $2 }
   | lbrace record_exprs rbrace { Expression.record_fields ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $2 }
 
-block:
-  | lbrace block_body rbrace { Expression.block ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $2 }
-
 arg_default:
   | EQUAL non_stmt_expr { $2 }
 
@@ -573,14 +570,14 @@ if_expr:
   | IF lparen expr rparen opt_eols expr ioption(else_expr) %prec _if { Expression.if_ ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $3 $6 $7 }
 
 while_expr:
-  | WHILE lparen expr rparen block { Expression.while_ ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $3 $5 }
+  | WHILE lparen expr rparen opt_eols expr { Expression.while_ ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $3 $6 }
 
 for_inner_expr:
   | %prec EOL { None }
   | expr { Some $1 }
 
 for_expr:
-  | FOR lparen block_body_expr? opt_eols SEMI opt_eols for_inner_expr opt_eols SEMI opt_eols for_inner_expr rparen block { Expression.for_ ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $3 $7 $11 $13 }
+  | FOR lparen block_body_expr? opt_eols SEMI opt_eols for_inner_expr opt_eols SEMI opt_eols for_inner_expr rparen opt_eols expr { Expression.for_ ~loc:(to_loc $loc) ~core_loc:(to_loc $loc) $3 $7 $11 $14 }
 
 when_guard:
   | opt_eols WHEN expr { $3 }

compiler/src/parsing/parser.mly

@@ -490,6 +490,7 @@ while (true /* true */) {
 while (true /* true */) {
   void
 }
+while (true /* true */) void
 
 for (/* for */
   /* init */
@@ -531,6 +532,7 @@ for (/* for */
 for (;; /* for */ /* init */ /*cond*/ /*inc*/ /* more */ /* and more */) {
   void
 }
+for (;; /* for */ /* init */ /*cond*/ /*inc*/ /* more */ /* and more */) void
 
 match (/* match */ /*foo*/ foo /* post foo */ /* post foo 2 */) { /* mr branch */
   _ => /* void */ void, /* post void */

compiler/test/grainfmt/comments.expected.gr

@@ -406,12 +406,14 @@ while /* true */ (true) {void}
 while (/* true */ true) {void}
 while (true /* true */) {void}
 while (true) /* true */ {void}
+while (true) /* true */ void
 
 for /* for */ (/* init */ let mut i = 1; /*cond*/i < 1; /*inc*/ i += 1 /* more */ )/* and more */ {void}
 for /* for */ (/* init */ ; /*cond*/i < 1; /*inc*/ i += 1 /* more */ )/* and more */ {void}
 for /* for */ (/* init */ let mut i = 1; /*cond*/; /*inc*/ i += 1 /* more */ )/* and more */ {void}
 for /* for */ (/* init */ let mut i = 1; /*cond*/i < 1; /*inc*/  /* more */ )/* and more */ {void}
 for /* for */ (/* init */ ; /*cond*/; /*inc*/  /* more */ )/* and more */ {void}
+for /* for */ (/* init */ ; /*cond*/; /*inc*/  /* more */ )/* and more */ void
 
 match /* match */ (/*foo*/ foo /* post foo */) /* post foo 2 */ {/* mr branch */_=> /* void */void/* post void */}
 

compiler/test/grainfmt/comments.input.gr

@@ -16,3 +16,5 @@ for (
   let strLength = 0
   print("Loop")
 }
+
+for (let mut i = 0; i < size; i += 1) print("Loop")

compiler/test/grainfmt/for_loops.expected.gr

@@ -12,3 +12,6 @@ let verylongvariablenameforcingalinebreakhereplease = 2
     let  strLength = 0
     print("Loop")
   }
+
+for (let mut i = 0; i < size; i += 1)
+  print("Loop")

compiler/test/grainfmt/for_loops.input.gr

@@ -6,3 +6,5 @@ let size = 10
 while (i < size) {
   i += 1
 }
+
+while (i < size) i += 1

compiler/test/grainfmt/while_loops.expected.gr

@@ -6,3 +6,6 @@ module WhileLoops
   while (i < size) {
     i = i + 1
   }
+
+while (i < size)
+  i = i + 1