labeled block statements

examples/programs/yield/main.bro

@@ -240,6 +240,45 @@ break_outer :: func() i32 {
 	return count # 5
 }
 
+# A labeled block *statement* (not a value source): `break :blk` exits it early.
+stmt_block :: func(early i32) i32 {
+	x i32 = 0
+	blk: {
+		x = 1
+		if (early == 1) break :blk
+		x = 2
+	}
+	return x # early == 1 -> 1, else 2
+}
+
+# `break :search` escapes a nested loop and the block in one jump; the block's
+# defer still runs on the way out.
+stmt_block_escape :: func() i32 {
+	hits i32 = 0
+	search: {
+		defer hits += 1000
+		for 0..10 |i| {
+			hits += 1
+			if (i == 3) break :search
+		}
+		hits += 100 # skipped by break :search
+	}
+	return hits # 4 + 1000 (defer) = 1004
+}
+
+# Item B: a `none` yielded before a concrete `yield :blk` that references a block local.
+lblock_local :: func() i32 {
+	r :: blk: {
+		val :: 9
+		if (false) yield :blk none
+		yield :blk val
+	}
+	if r |v| {
+		return v
+	}
+	return -1
+}
+
 main :: func() i32 {
 	if (basic() != 42) return 101
 	if (typed() != 100) return 102
@@ -276,5 +315,10 @@ main :: func() i32 {
 	if (yield_outer(99) != -1) return 129
 	if (break_outer() != 5) return 130
 
+	if (stmt_block(1) != 1) return 131
+	if (stmt_block(0) != 2) return 132
+	if (stmt_block_escape() != 1004) return 133
+	if (lblock_local() != 9) return 134
+
 	return 42
 }