fmt: process `MatchExpr`

vlib/v/fmt/fmt.v

@@ -438,6 +438,29 @@ fn (f mut Fmt) expr(node ast.Expr) {
 			f.indent--
 			f.write('}')
 		}
+		ast.MatchExpr {
+			f.write('match ')
+			f.expr(it.cond)
+			f.writeln(' {')
+			f.indent++
+			for i, expr in it.match_exprs {
+				f.expr(expr)
+				f.writeln(' {')
+				f.stmts(it.blocks[i].stmts)
+				f.writeln('}')
+			}
+
+			else_stmts := it.blocks[it.blocks.len - 1].stmts
+			if (else_stmts.len == 0) {
+				f.writeln('else {}')
+			} else {
+				f.writeln('else {')
+				f.stmts(else_stmts)
+				f.writeln('}')
+			}
+			f.indent--
+			f.write('}')
+		}
 		ast.MethodCallExpr {
 			f.expr(it.expr)
 			f.write('.' + it.name + '(')

vlib/v/fmt/tests/simple_expected.vv

@@ -158,3 +158,27 @@ fn (f Foo) method_with_or() int {
 	}
 	return 20
 }
+
+fn fn_with_match_expr() {
+	a := 10
+	b := match a {
+		10 {
+			10
+		}
+		5 {
+			5
+		}
+		else {
+			2
+		}
+	}
+	match b {
+		10 {
+			println('10')
+		}
+		20 {
+			println('20')
+		}
+		else {}
+	}
+}

vlib/v/fmt/tests/simple_input.vv

@@ -158,3 +158,27 @@ fn (f Foo) method_with_or() int {
 	}
 	return 20
 }
+
+fn fn_with_match_expr() {
+	a := 10
+	b := match a {
+		10 {
+			10
+		}
+		5 {
+			5
+		}
+		else {
+			2
+		}
+	}
+	match b {
+		10 {
+			println('10')
+		}
+		20 {
+			println('20')
+		}
+		else {}
+	}
+}