From c28a490c17e392a1b75fc969717c713f62e80676 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 24 Jul 2019 02:22:34 +0200
Subject: [PATCH] @ for escaping keywords

---
 compiler/parser.v            | 9 +++------
 compiler/scanner.v           | 7 +++++++
 compiler/tests/struct_test.v | 9 +++++++++
 compiler/token.v             | 2 ++
 4 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/compiler/parser.v b/compiler/parser.v
index 25e718621f..ff9b299cb0 100644
--- a/compiler/parser.v
+++ b/compiler/parser.v
@@ -1335,7 +1335,7 @@ fn (p mut Parser) bterm() string {
 	return typ
 }
 
-// also called on *, &, . (enum) 
+// also called on *, &, @, . (enum) 
 fn (p mut Parser) name_expr() string {
 	p.log('\nname expr() pass=$p.run tok=${p.tok.str()} $p.lit')
 	// print('known type:')
@@ -2167,11 +2167,8 @@ fn (p mut Parser) factor() string {
 		p.gen('$sizeof_typ)')
 		p.fgen('$sizeof_typ)')
 		return 'int'
-	case Token.amp:
-		return p.name_expr()
-	case Token.dot:
-		return p.name_expr()// `.green` (enum)
-	case Token.mul:
+	case Token.amp, Token.dot, Token.mul: 
+		// (dot is for enum vals: `.green`) 
 		return p.name_expr()
 	case Token.name:
 		// map[string]int
diff --git a/compiler/scanner.v b/compiler/scanner.v
index dcaa432acd..351e3108be 100644
--- a/compiler/scanner.v
+++ b/compiler/scanner.v
@@ -388,6 +388,13 @@ fn (s mut Scanner) scan() ScanRes {
 		return scan_res(.pipe, '')
 	case `,`:
 		return scan_res(.comma, '')
+	case `@`:
+		s.pos++ 
+		name := s.ident_name()
+		if !is_key(name) {
+			s.error('@ must be used before keywords (e.g. `@type string`)') 
+		} 
+		return scan_res(.name, name)
 	case `\r`:
 		if nextc == `\n` {
 			s.pos++
diff --git a/compiler/tests/struct_test.v b/compiler/tests/struct_test.v
index d54d42a044..8f36f434a2 100644
--- a/compiler/tests/struct_test.v
+++ b/compiler/tests/struct_test.v
@@ -21,6 +21,10 @@ struct User {
 	name string
 	age int 
 } 
+
+struct Foo {
+	@type string 
+} 
  
 fn test_struct_levels() { 
 	mut c := C{} 
@@ -54,3 +58,8 @@ fn test_struct_str() {
 	println(u)  // make sure the struct is printable 
 	// assert u.str() == '{name:"Bob", age:30}'  // TODO 
 } 
+
+fn test_at() {
+	foo := Foo{ @type: 'test' } 
+	println(foo.@type) 
+} 
diff --git a/compiler/token.v b/compiler/token.v
index e1d3cec95c..dc69a0021c 100644
--- a/compiler/token.v
+++ b/compiler/token.v
@@ -34,6 +34,7 @@ enum Token {
 	dollar
 	left_shift
 	righ_shift
+	//at // @ 
 	// = := += -=
 	assign
 	decl_assign
@@ -148,6 +149,7 @@ fn build_token_str() []string {
 	s[Token.dot] = '.'
 	s[Token.dotdot] = '..'
 	s[Token.comma] = ','
+	//s[Token.at] = '@'
 	s[Token.semicolon] = ';'
 	s[Token.colon] = ':'
 	s[Token.arrow] = '=>'