private PdeRecognizer createParser(final String program) {
// create a lexer with the stream reader, and tell it to handle
// hidden tokens (eg whitespace, comments) since we want to pass these
// through so that the line numbers when the compiler reports errors
// match those that will be highlighted in the PDE IDE
//
PdeLexer lexer = new PdeLexer(new StringReader(program));
lexer.setTokenObjectClass("antlr.CommonHiddenStreamToken");
// create the filter for hidden tokens and specify which tokens to
// hide and which to copy to the hidden text
//
filter = new TokenStreamCopyingHiddenTokenFilter(lexer);
filter.hide(PdePartialTokenTypes.SL_COMMENT);
filter.hide(PdePartialTokenTypes.ML_COMMENT);
filter.hide(PdePartialTokenTypes.WS);
filter.copy(PdePartialTokenTypes.SEMI);
filter.copy(PdePartialTokenTypes.LPAREN);
filter.copy(PdePartialTokenTypes.RPAREN);
filter.copy(PdePartialTokenTypes.LCURLY);
filter.copy(PdePartialTokenTypes.RCURLY);
filter.copy(PdePartialTokenTypes.COMMA);
filter.copy(PdePartialTokenTypes.RBRACK);
filter.copy(PdePartialTokenTypes.LBRACK);
filter.copy(PdePartialTokenTypes.COLON);
filter.copy(PdePartialTokenTypes.TRIPLE_DOT);
// Because the meanings of < and > are overloaded to support
// type arguments and type parameters, we have to treat them
// as copyable to hidden text (or else the following syntax,
// such as (); and what not gets lost under certain circumstances)
// -- jdf
filter.copy(PdePartialTokenTypes.LT);
filter.copy(PdePartialTokenTypes.GT);
filter.copy(PdePartialTokenTypes.SR);
filter.copy(PdePartialTokenTypes.BSR);
// create a parser and set what sort of AST should be generated
//
final PdeRecognizer parser = new PdeRecognizer(this, filter);
// use our extended AST class
//
parser.setASTNodeClass("antlr.ExtendedCommonASTWithHiddenTokens");
return parser;
}
/**
* preprocesses a pde file and writes out a java file
*
* @return the class name of the exported Java
*/
private String write(final String program, final PrintWriter stream)
throws SketchException, RecognitionException, TokenStreamException {
// Match on the uncommented version, otherwise code inside comments used
// http://code.google.com/p/processing/issues/detail?id=1404
String uncomment = scrubComments(program);
PdeRecognizer parser = createParser(program);
if (PUBLIC_CLASS.matcher(uncomment).find()) {
try {
final PrintStream saved = System.err;
try {
// throw away stderr for this tentative parse
System.setErr(new PrintStream(new ByteArrayOutputStream()));
parser.javaProgram();
} finally {
System.setErr(saved);
}
setMode(Mode.JAVA);
} catch (Exception e) {
// I can't figure out any other way of resetting the parser.
parser = createParser(program);
parser.pdeProgram();
}
} else if (FUNCTION_DECL.matcher(uncomment).find()) {
setMode(Mode.ACTIVE);
parser.activeProgram();
} else {
parser.pdeProgram();
}
// set up the AST for traversal by PdeEmitter
//
ASTFactory factory = new ASTFactory();
AST parserAST = parser.getAST();
AST rootNode = factory.create(ROOT_ID, "AST ROOT");
rootNode.setFirstChild(parserAST);
makeSimpleMethodsPublic(rootNode);
// unclear if this actually works, but it's worth a shot
//
// ((CommonAST)parserAST).setVerboseStringConversion(
// true, parser.getTokenNames());
// (made to use the static version because of jikes 1.22 warning)
BaseAST.setVerboseStringConversion(true, parser.getTokenNames());
final String className;
if (mode == Mode.JAVA) {
// if this is an advanced program, the classname is already defined.
className = getFirstClassName(parserAST);
} else {
className = this.name;
}
// if 'null' was passed in for the name, but this isn't
// a 'java' mode class, then there's a problem, so punt.
//
if (className == null) return null;
// debug
if (false) {
final StringWriter buf = new StringWriter();
final PrintWriter bufout = new PrintWriter(buf);
writeDeclaration(bufout, className);
new PdeEmitter(this, bufout).print(rootNode);
writeFooter(bufout, className);
debugAST(rootNode, true);
System.err.println(buf.toString());
}
writeDeclaration(stream, className);
new PdeEmitter(this, stream).print(rootNode);
writeFooter(stream, className);
// if desired, serialize the parse tree to an XML file. can
// be viewed usefully with Mozilla or IE
if (Preferences.getBoolean("preproc.output_parse_tree")) {
writeParseTree("parseTree.xml", parserAST);
}
return className;
}