From 99cf520bd4fbabf15ffada675e6535cda0611daa Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 6 May 2020 12:13:19 +0200
Subject: [PATCH] parser: `mut x Type` syntax for args

---
 vlib/v/parser/fn.v     | 12 ++++++++----
 vlib/v/tests/fn_test.v |  8 ++++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index e0bc65c527..5c4dbb35cc 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -358,16 +358,20 @@ fn (mut p Parser) fn_args() ([]table.Arg, bool) {
 		}
 	} else {
 		for p.tok.kind != .rpar {
+			mut is_mut := p.tok.kind == .key_mut
+			if is_mut {
+				p.next()
+			}
 			mut arg_names := [p.check_name()]
 			// `a, b, c int`
 			for p.tok.kind == .comma {
 				p.check(.comma)
 				arg_names << p.check_name()
 			}
-			is_mut := p.tok.kind == .key_mut
-			// if is_mut {
-			// p.check(.key_mut)
-			// }
+			if p.tok.kind == .key_mut {
+				// TODO remove old syntax
+				is_mut = true
+			}
 			if p.tok.kind == .ellipsis {
 				p.check(.ellipsis)
 				is_variadic = true
diff --git a/vlib/v/tests/fn_test.v b/vlib/v/tests/fn_test.v
index 902991285e..1ee3ea0b2e 100644
--- a/vlib/v/tests/fn_test.v
+++ b/vlib/v/tests/fn_test.v
@@ -65,6 +65,14 @@ fn modify_array(a mut []int) {
 	// a << 888
 }
 
+fn modify_array2(mut a []int) {
+	a[0] = 10
+	for i in 0 .. a.len {
+		a[i] = a[i] * 2
+	}
+	// a << 888
+}
+
 fn test_mut_array() {
 	mut nums := [1, 2, 3]
 	modify_array(mut nums)