Parse new library syntax.

dart/lib/compiler/implementation/scanner/parser.dart

 // Copyright (c) 2012, 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.
 
 /**
  * An event generating parser of Dart programs. This parser expects
  * all tokens in a linked list (aka a token stream).
  *
  * The class [Scanner] is used to generate a token stream. See the
  * file scanner.dart.
@@ skipping 30 matching lines @@
     token = parseMetadataStar(token);
     final String value = token.stringValue;
     if (value === 'interface') {
       return parseInterface(token);
     } else if ((value === 'abstract') || (value === 'class')) {
       return parseClass(token);
     } else if (value === 'typedef') {
       return parseNamedFunctionAlias(token);
     } else if (value === '#') {
       return parseScriptTags(token);
+    } else if (value === 'library') {
+      return parseLibraryName(token);
+    } else if (value === 'import') {
+      return parseImport(token);
+    } else if (value === 'export') {
+      return parseExport(token);

[Lasse Reichstein Nielsen, 2012/09/14 09:36:09]

Are we not supporting "part"?

[ahe, 2012/09/14 12:13:53]

Not yet.

     } else {
       return parseTopLevelMember(token);
     }
   }
 
+  /// library qualified ';'
+  Token parseLibraryName(Token token) {
+    Token libraryKeyword = token;
+    listener.beginLibraryName(libraryKeyword);
+    assert(optional('library', token));
+    token = parseIdentifier(token.next);
+    while (optional('.', token)) {
+      token = parseQualifiedRest(token);
+    }
+    Token semicolon = token;
+    token = expect(';', token);
+    listener.endLibraryName(libraryKeyword, semicolon);
+    return token;
+  }
+
+  /// import uri (as identifier)? combinator* ';'
+  Token parseImport(Token token) {
+    Token importKeyword = token;
+    listener.beginImport(importKeyword);
+    assert(optional('import', token));
+    token = parseLiteralStringOrRecoverExpression(token.next);
+    Token asKeyword;
+    if (optional('as', token)) {
+      asKeyword = token;
+      token = parseIdentifier(token.next);
+    }
+    token = parseCombinators(token);
+    Token semicolon = token;
+    token = expect(';', token);
+    listener.endImport(importKeyword, asKeyword, semicolon);
+    return token;
+  }
+
+  /// export uri combinator* ';'
+  Token parseExport(Token token) {
+    Token exportKeyword = token;
+    listener.beginExport(exportKeyword);
+    assert(optional('export', token));
+    token = parseLiteralStringOrRecoverExpression(token.next);
+    listener.popNode(); // TODO(ahe): Hack.

[Johnni Winther, 2012/09/14 09:18:22]

Why not just pop the node in endExport and discard it there?

[ahe, 2012/09/14 12:13:53]

I missed that. I was not supposed to upload the CL with these lines. I don't
think Unipro has seen this language feature yet, so there are no tests (yet).

+    token = parseCombinators(token);
+    Token semicolon = token;
+    token = expect(';', token);
+    listener.endExport(exportKeyword, semicolon);
+    return token;
+  }
+
+  Token parseCombinators(Token token) {
+    listener.beginCombinators(token);
+    int count = 0;
+    while (true) {
+      String value = token.stringValue;
+      if ('hide' === value) {

[Lasse Reichstein Nielsen, 2012/09/14 09:36:09]

Why not (value === 'hide')?

[ahe, 2012/09/14 12:13:53]

Because I felt like it.

+        token = parseHide(token);
+      } else if ('show' === value) {
+        token = parseShow(token);
+      } else {
+        listener.endCombinators(count);
+        return token;
+      }
+      count++;
+    }
+  }
+
+  /// hide identifierList

[Lasse Reichstein Nielsen, 2012/09/14 09:36:09]

Make comment sentence. (Capitalized start, full stop at end).
Also notice that /// is a doc-comment now.

[ahe, 2012/09/14 12:13:53]

This is a doc comment that makes sense in this place. It is not a sentence
because it is a grammar rule.

+  Token parseHide(Token token) {
+    Token hideKeyword = token;
+    listener.beginHide(hideKeyword);
+    assert(optional('hide', token));
+    token = parseIdentifierList(token.next);
+    listener.endHide(hideKeyword);
+    return token;
+  }
+
+  /// show identifierList
+  Token parseShow(Token token) {
+    Token showKeyword = token;
+    listener.beginShow(showKeyword);
+    assert(optional('show', token));
+    token = parseIdentifierList(token.next);
+    listener.endShow(showKeyword);
+    return token;
+  }
+
+  /// identifier (, identifier)*
+  Token parseIdentifierList(Token token) {
+    listener.beginIdentifierList(token);
+    int count = 0;
+    do {
+      token = parseIdentifier(token);
+      count++;
+    } while (optional(',', token));

[Johnni Winther, 2012/09/14 09:18:22]

If this is true token should also be updated to token = token.next to step over
the comma.

[Lasse Reichstein Nielsen, 2012/09/14 09:36:09]

Missing token = token.next after recognizing ','.
How about:
  
  token = parseIdentifier(token);
  int count = 1;
  while (optional(',', token)) {
    token = parseIdentifier(token.next);
    count++;
  }

[ahe, 2012/09/14 12:13:53]

This is what I had originally. I should have stuck to that :-)

+    listener.endIdentifierList(count);
+    return token;
+  }
+
   Token parseMetadataStar(Token token) {
     while (optional('@', token)) {
       token = parseMetadata(token);
     }
     return token;
   }
 
   /**
    * Parse
    * [: '@' qualified (‘.’ identifier)? (arguments)? :]
@@ skipping 169 matching lines @@
       token = parseTypeVariablesOpt(token);
       listener.endDefaultClause(defaultKeyword);
     } else {
       listener.handleNoDefaultClause(token);
     }
     return token;
   }
 
   Token parseQualifiedRestOpt(Token token) {
     if (optional('.', token)) {
-      Token period = token;
-      token = parseIdentifier(token.next);
-      listener.handleQualified(period);
+      return parseQualifiedRest(token);
+    } else {
+      return token;
     }
+  }
+
+  Token parseQualifiedRest(Token token) {
+    assert(optional('.', token));
+    Token period = token;
+    token = parseIdentifier(token.next);
+    listener.handleQualified(period);
     return token;
   }
 
   bool isDefaultKeyword(Token token) {
     String value = token.stringValue;
     if (value === 'default') return true;
     if (value === 'factory') {
       listener.recoverableError("expected 'default'", token: token);
       return true;
     }
@@ skipping 1669 matching lines @@
     }
     listener.handleContinueStatement(hasTarget, continueKeyword, token);
     return expectSemicolon(token);
   }
 
   Token parseEmptyStatement(Token token) {
     listener.handleEmptyStatement(token);
     return expectSemicolon(token);
   }
 }