From 2080557f50c17024d1f52a06046b36d23043b379 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Thu, 21 Apr 2022 13:15:21 +0300
Subject: [PATCH] ast: allow `a := match x { 101 { ... for {...} ... y }`

---
 vlib/v/ast/ast.v                              |  3 +
 vlib/v/checker/tests/if_match_expr.out        |  7 ---
 .../match_expression_with_for_loop_test.v     | 58 +++++++++++++++++++
 3 files changed, 61 insertions(+), 7 deletions(-)
 create mode 100644 vlib/v/tests/match_expression_with_for_loop_test.v

diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index 06e898bb50..bce6e6d7f4 100644
--- a/vlib/v/ast/ast.v
+++ b/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
diff --git a/vlib/v/checker/tests/if_match_expr.out b/vlib/v/checker/tests/if_match_expr.out
index 81c13a7f69..bb4dc85293 100644
--- a/vlib/v/checker/tests/if_match_expr.out
+++ b/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}
diff --git a/vlib/v/tests/match_expression_with_for_loop_test.v b/vlib/v/tests/match_expression_with_for_loop_test.v
new file mode 100644
index 0000000000..c86ea6ae22
--- /dev/null
+++ b/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]
+}