v2: initial interface support; fix enum_hex_test.v

vlib/v/parser/parser.v

@@ -52,7 +52,7 @@ pub fn parse_stmt(text string, table &table.Table, scope &ast.Scope) ast.Stmt {
 		pref: &pref.Preferences{}
 		scope: scope
 		// scope: &ast.Scope{start_pos: 0, parent: 0}
-
+		
 	}
 	p.init_parse_fns()
 	p.read_first_token()
@@ -71,13 +71,13 @@ pub fn parse_file(path string, table &table.Table, comments_mode scanner.Comment
 		table: table
 		file_name: path
 		pref: pref // &pref.Preferences{}
-
+		
 		scope: &ast.Scope{
 			start_pos: 0
 			parent: 0
 		}
 		// comments_mode: comments_mode
-
+		
 	}
 	p.read_first_token()
 	// p.scope = &ast.Scope{start_pos: p.tok.position(), parent: 0}
@@ -275,6 +275,9 @@ pub fn (p mut Parser) top_stmt() ast.Stmt {
 		.lsbr {
 			return p.attribute()
 		}
+		.key_interface {
+			return p.interface_decl()
+		}
 		.key_module {
 			return p.module_decl()
 		}
@@ -688,7 +691,7 @@ pub fn (p mut Parser) name_expr() ast.Expr {
 		p.expr_mod = ''
 		return ast.EnumVal{
 			enum_name: enum_name // lp.prepend_mod(enum_name)
-
+			
 			val: val
 			pos: p.tok.position()
 			mod: mod
@@ -778,7 +781,7 @@ pub fn (p mut Parser) expr(precedence int) ast.Expr {
 			node = ast.SizeOf{
 				typ: sizeof_type
 				// type_name: type_name
-
+				
 			}
 		}
 		.key_typeof {
@@ -1049,7 +1052,7 @@ fn (p mut Parser) infix_expr(left ast.Expr) ast.Expr {
 		left: left
 		right: right
 		// right_type: typ
-
+		
 		op: op
 		pos: pos
 	}
@@ -1454,7 +1457,7 @@ fn (p mut Parser) const_decl() ast.ConstDecl {
 		fields << ast.Field{
 			name: name
 			// typ: typ
-
+			
 		}
 		exprs << expr
 		// TODO: once consts are fixed reg here & update in checker
@@ -1581,6 +1584,28 @@ fn (p mut Parser) struct_decl() ast.StructDecl {
 	}
 }
 
+fn (p mut Parser) interface_decl() ast.InterfaceDecl {
+	is_pub := p.tok.kind == .key_pub
+	if is_pub {
+		p.next()
+	}
+	p.next() // `interface`
+	interface_name := p.check_name()
+	p.check(.lcbr)
+	for p.tok.kind != .rcbr && p.tok.kind != .eof {
+		line_nr := p.tok.line_nr
+		name := p.check_name()
+		p.fn_args()
+		if p.tok.kind == .name && p.tok.line_nr == line_nr {
+			p.parse_type()
+		}
+	}
+	p.check(.rcbr)
+	return ast.InterfaceDecl{
+		name: interface_name
+	}
+}
+
 fn (p mut Parser) return_stmt() ast.Return {
 	p.next()
 	// return expressions