ast: allow `a := match x { 101 { ... for {...} ... y }`

vlib/v/ast/ast.v

@@ -1821,6 +1821,9 @@ pub fn (stmt Stmt) check_c_expr() ? {
 		AssignStmt {
 			return
 		}
+		ForCStmt, ForInStmt, ForStmt {
+			return
+		}
 		ExprStmt {
 			if stmt.expr.is_expr() {
 				return

vlib/v/checker/tests/if_match_expr.out

@@ -1,10 +1,3 @@
-vlib/v/checker/tests/if_match_expr.vv:8:6: error: `if` expression branch has unsupported statement (`v.ast.ForStmt`)
-    6 |     if true {1} else {-1} // result
-    7 | } else {
-    8 |     for {break}
-      |         ^
-    9 |     {}
-   10 |     match true {true {} else {}} // statement not expression
 vlib/v/checker/tests/if_match_expr.vv:9:2: error: `if` expression branch has unsupported statement (`v.ast.Block`)
     7 | } else {
     8 |     for {break}

vlib/v/tests/match_expression_with_for_loop_test.v

@@ -0,0 +1,58 @@
+fn test_match_with_for_in_loop() {
+	a := 101
+	b := match a {
+		101 {
+			mut aa := []int{}
+			for i in 0 .. 3 {
+				aa << i
+			}
+			aa
+		}
+		else {
+			[0]
+		}
+	}
+	println(b)
+	assert b == [0, 1, 2]
+}
+
+fn test_match_with_for_c_loop() {
+	a := 101
+	b := match a {
+		101 {
+			mut aa := []int{}
+			for i := 0; i < 3; i++ {
+				aa << i
+			}
+			aa
+		}
+		else {
+			[0]
+		}
+	}
+	println(b)
+	assert b == [0, 1, 2]
+}
+
+fn test_match_with_for_loop() {
+	a := 101
+	b := match a {
+		101 {
+			mut aa := []int{}
+			mut i := 0
+			for {
+				aa << i
+				i++
+				if i == 3 {
+					break
+				}
+			}
+			aa
+		}
+		else {
+			[0]
+		}
+	}
+	println(b)
+	assert b == [0, 1, 2]
+}