Beginning of CSS parser using frog parsering infrastructure.

utils/css/tokenkind.dart

Index: utils/css/tokenkind.dart
diff --git a/utils/css/tokenkind.dart b/utils/css/tokenkind.dart
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+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class TokenKind {
+  // Common shared tokens used in TokenizerBase.
+  static final int END_OF_FILE = 0;
+  static final int LPAREN = 1;
+  static final int RPAREN = 2;
+  static final int LBRACK = 3;
+  static final int RBRACK = 4;
+  static final int LBRACE = 5;
+  static final int RBRACE = 6;
+  static final int DOT = 7;
+
+  // Unique tokens for CSS.
+  static final int AT = 8;
+  static final int HASH = 9;
+  static final int COMBINATOR_PLUS = 10;
+  static final int COMBINATOR_GREATER = 11;
+  static final int COMBINATOR_TILDE = 12;

[nweiz, 2011/11/10 00:04:40]

I don't like how some of these token names encode the semantics of how the token
is used in CSS (NAMESPACE, PSEUDO, PRIVATE_NAME), others refer only to the
character that makes up the token (AT, HASH, ASTERISK, COMMA), and still others
(COMBINATOR_*) include both. I'd say choose one and make it consistent.

[terry, 2011/11/22 16:40:47]

You have a valid point I'll clean this up next checkin.  Added TODO.
On 2011/11/10 00:04:40, nweiz wrote:

+  static final int ASTERISK = 13;
+  static final int NAMESPACE = 14;
+  static final int PSEUDO = 15;
+  static final int PRIVATE_NAME = 16;           // _ prefix private class or id
+  static final int COMMA = 17;
+
+  // WARNING: END_TOKENS must match above token number (last character in our
+  //          list).  Also add to kindToString function and the constructor
+  //          for TokenKind.
+
+  static final int END_TOKENS = 17;             // Marker for last token in list
+
+  // Synthesized Tokens (no character associated with TOKEN).
+  // TODO(terry): Possible common names used by both Dart and CSS tokenizers.
+  static final int STRING = 500;
+  static final int STRING_PART = 501;
+  static final int NUMBER = 502;
+  static final int HEX_NUMBER = 503;
+  static final int WHITESPACE = 504;
+  static final int COMMENT = 505;
+  static final int ERROR = 506;
+  static final int INCOMPLETE_STRING = 507;
+  static final int INCOMPLETE_COMMENT = 508;
+  static final int INCOMPLETE_MULTILINE_STRING_DQ = 509;

[nweiz, 2011/11/10 00:04:40]

Unused constants

[terry, 2011/11/22 16:40:47]

I think I'll be using these soon enough.
On 2011/11/10 00:04:40, nweiz wrote:

+  static final int INCOMPLETE_MULTILINE_STRING_SQ = 510;
+  static final int IDENTIFIER = 511;
+
+  // Uniquely synthesized tokens for CSS.
+  static final int SELECTOR_EXPRESSION = 512;
+  static final int COMBINATOR_NONE = 513;
+
+  // Attribute match:
+  static final int INCLUDES_MATCH = 514;        // ~=
+  static final int DASH_MATCH = 515;            // |=
+  static final int PREFIX_MATCH = 516;          // ^=
+  static final int SUFFIX_MATCH = 517;          // $=
+  static final int STRING_MATCH = 518;          // *=
+  static final int EQUAL_MATCH = 519;           // =
+
+  // Simple selector type.
+  static final int CLASS_NAME = 700;            // .class
+  static final int ELEMENT_NAME = 701;          // tagName
+  static final int HASH_NAME = 702;             // #elementId
+  static final int ATTRIBUTE_NAME = 703;        // [attrib]
+  static final int PSEUDO_ELEMENT_NAME = 704;   // ::pseudoElement
+  static final int PSEUDO_CLASS_NAME = 705;     // :pseudoClass
+  static final int NEGATION = 706;              // NOT
+
+  List<int> tokens;
+
+  static String kindToString(int kind) {
+    switch(kind) {
+      case TokenKind.END_OF_FILE: return "end of file";
+      case TokenKind.LPAREN: return "(";
+      case TokenKind.RPAREN: return ")";
+      case TokenKind.LBRACK: return "[";
+      case TokenKind.RBRACK: return "[";
+      case TokenKind.LBRACE: return "{";
+      case TokenKind.RBRACE: return "}";
+      case TokenKind.DOT: return ".";
+      case TokenKind.AT: return "@";
+      case TokenKind.HASH: return "#";
+      case TokenKind.COMBINATOR_PLUS: return "+";
+      case TokenKind.COMBINATOR_GREATER: return ">";
+      case TokenKind.COMBINATOR_TILDE: return "~";
+      case TokenKind.ASTERISK: return "*";
+      case TokenKind.NAMESPACE: return "|";
+      case TokenKind.PSEUDO: return ":";
+      case TokenKind.PRIVATE_NAME: return "_";
+      case TokenKind.COMMA: return ",";
+      default:
+        throw "Unknown TOKEN";
+    }
+  }
+
+  TokenKind() {

[nweiz, 2011/11/10 00:04:40]

Why is this a class that gets instantiated? Wouldn't it be just as easy, and
much more efficient and less verbose, to manually assign the relevant character
codes to constants?

[terry, 2011/11/22 16:40:47]

For now I'm trying to mimic frog w/o the Python class creations.
On 2011/11/10 00:04:40, nweiz wrote:

+    tokens = [];
+
+    // All tokens must be in TokenKind order.
+    tokens.add(0);                                      // TokenKind.END_OF_FILE
+    tokens.add(TokenKind.kindToString(TokenKind.LPAREN).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.RPAREN).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.LBRACK).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.RBRACK).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.LBRACE).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.RBRACE).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.DOT).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.AT).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.HASH).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.COMBINATOR_PLUS).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.COMBINATOR_GREATER).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.COMBINATOR_TILDE).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.ASTERISK).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.NAMESPACE).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.PSEUDO).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.PRIVATE_NAME).charCodeAt(0));
+    tokens.add(TokenKind.kindToString(TokenKind.COMMA).charCodeAt(0));
+
+    assert(tokens.length == TokenKind.END_TOKENS);
+  }
+
+  static bool isIdentifier(int kind) {
+    return kind == IDENTIFIER ;
+  }
+}