v2: raw strings

vlib/builtin/array_test.v

@@ -267,7 +267,6 @@ fn test_reverse() {
 	for i, _ in d {
 		assert d[i] == b[b.len - i - 1]
 	}
-
 	e := []int
 	f := e.reverse()
 	assert f.len == 0

vlib/v/ast/ast.v

@@ -56,7 +56,9 @@ pub:
 
 pub struct StringLiteral {
 pub:
-	val string
+	val    string
+	is_raw bool
+	is_c   bool
 }
 
 // 'name: $name'

vlib/v/checker/checker.v

@@ -602,7 +602,7 @@ fn (c mut Checker) stmt(node ast.Stmt) {
 				value_type := c.table.value_type(typ)
 				if value_type == table.void_type {
 					typ_sym := c.table.get_type_symbol(typ)
-					c.error('for in: cannot index $typ_sym.name', it.pos)
+					c.error('for in: cannot index `$typ_sym.name`', it.pos)
 				}
 				it.cond_type = typ
 				it.kind = sym.kind

vlib/v/parser/parser.v

@@ -594,6 +594,11 @@ pub fn (p mut Parser) name_expr() ast.Expr {
 			typ: map_type
 		}
 	}
+	// Raw string (`s := r'hello \n ')
+	if p.tok.lit == 'r' && p.peek_tok.kind == .string {
+		// && p.prev_tok.kind != .str_dollar {
+		return p.string_expr()
+	}
 	known_var := p.scope.known_var(p.tok.lit)
 	if p.peek_tok.kind == .dot && !known_var && (is_c || p.known_import(p.tok.lit) || p.mod.all_after('.') == p.tok.lit) {
 		if is_c {
@@ -1248,10 +1253,17 @@ fn (p mut Parser) if_expr() ast.IfExpr {
 }
 
 fn (p mut Parser) string_expr() ast.Expr {
+	is_raw := p.tok.kind == .name && p.tok.lit == 'r'
+	is_cstr := p.tok.kind == .name && p.tok.lit == 'c'
+	if is_raw || is_cstr {
+		p.next()
+	}
 	mut node := ast.Expr{}
 	val := p.tok.lit
 	node = ast.StringLiteral{
 		val: val
+		is_raw: is_raw
+		is_c: is_cstr
 	}
 	if p.peek_tok.kind != .str_dollar {
 		p.next()