Support for parsing CSS operators.

lib/oga/css/lexer.rl

@@ -147,7 +147,7 @@ module Oga
         # Identifiers are used for element and attribute names. Identifiers have
         # to start with a letter.
 
-        identifier = [a-zA-Z*]+ [a-zA-Z\-_0-9]*;
+        identifier = '*' | [a-zA-Z]+ [a-zA-Z\-_0-9]*;
 
         action emit_identifier {
           emit(:T_IDENT, ts, te)
@@ -184,6 +184,23 @@ module Oga
           add_token(:T_INT, value)
         }
 
+        # Strings
+        #
+        # Strings can be single or double quoted. They are mainly used for
+        # attribute values.
+        #
+        dquote = '"';
+        squote = "'";
+
+        string_dquote = (dquote ^dquote* dquote);
+        string_squote = (squote ^squote* squote);
+
+        string = string_dquote | string_squote;
+
+        action emit_string {
+          emit(:T_STRING, ts + 1, te - 1)
+        }
+
         # Nth numbers
         #
         # These numbers are in the form of 2n+1 and are used for
@@ -236,6 +253,7 @@ module Oga
           nth_integer    => emit_nth_integer;
           nth_identifier => emit_nth_identifier;
           integer        => emit_integer;
+          string         => emit_string;
 
           any;
         *|;

lib/oga/css/parser.y

@@ -14,6 +14,7 @@ rule
   expression
     : path
     | node_test
+    | node_operators
     ;
 
   path_member
@@ -46,7 +47,39 @@ rule
     ;
 
   predicate
-    : T_LBRACK expression T_RBRACK { val[1] }
+    : T_LBRACK predicate_members T_RBRACK { val[1] }
+    ;
+
+  predicate_members
+    : expression { val[0] }
+    | operator   { val[0] }
+    ;
+
+  operator
+    : op_members T_EQ          op_members { s(:eq, val[0], val[2]) }
+    | op_members T_SPACE_IN    op_members { s(:space_in, val[0], val[2]) }
+    | op_members T_STARTS_WITH op_members { s(:starts_with, val[0], val[2]) }
+    | op_members T_ENDS_WITH   op_members { s(:ends_with, val[0], val[2]) }
+    | op_members T_IN          op_members { s(:in, val[0], val[2]) }
+    | op_members T_HYPHEN_IN   op_members { s(:hyphen_in, val[0],val[2]) }
+    ;
+
+  node_operators
+    : node_test T_CHILD     node_test { s(:child, val[0], val[2]) }
+    | node_test T_FOLLOWING node_test { s(:following, val[0], val[2]) }
+    | node_test T_FOLLOWING_DIRECT node_test
+      {
+        s(:following_direct, val[0], val[2])
+      }
+    ;
+
+  op_members
+    : node_test
+    | string
+    ;
+
+  string
+    : T_STRING { s(:string, val[0]) }
     ;
 end