Examples of PtParser

ptolemy.data.expr.PtParser
This file implements an expression parser for Ptolemy II using the JavaCC parser generator. It can handle all the basic arithmetic operators (*, /, +, -, %, ^), relational operators (<, <=,>, >=, == !=), logical operators(&&, ||, !), bitwise operators (&, |, #, ~) and, using reflection, all of the functionality available in the java.lang.Math package.
By editing the ASTFunctionNode file it is also relatively easy to allow references to other functions. This provides an easy mechanism to extend the range to the parser e.g. have a tcl(...) function that passes the string to a Tcl interpreter and retuns the result.
Functional if is supported via the following syntax: (boolean) ? (value1) : (value2)
Extensibility is also supported by allowing method calls on the Tokens, the syntax is (value1).method(comma separated arguments)
JavaCC by itself simply generates a file (and support files) that allow an input to be parsed, it does not return a parse tree. For the purposes of type checking we require a parse tree, and this is obtained using JJTree, a preprocessor for JavaCC.
JJtree operates by annotating the grammar file to support the generation of the parse tree. Thus the process is

X.jjt --> JJTREE --> X.jj --> JAVACC --> X.java + support files

The parser can also be passed a symbol table of ptolemy.data.expr.Variables which the expression to be parsed can reference.
Anything between quotes(") or apostrophes(') is taken to be one string. Strings are allowed to contain newlines or carriage returns. In addition, these characters, as well as other special characters, can be escaped using the standard Java syntax (\n, \t, \077, etc.).
The expressions recognized follow as close as possible the syntax of Java. In particular the operator precedences implemented here follow exactly those in Java. Any type conversions that are performed are lossless. If the user wants lossy conversions, explicit casts will be necessary.
Complex number are specified by an i or j after the imaginary part of the number. Long numbers are specified by an l or L after an integer number.
Users can register constants with the parser and also register classes where functions that may be called are defined. For a more thorough description of what the Parser is designed to do, please consult the Ptolemy II design document (or contact nsmyth@eecs)
Note that the parsers created by JavaCC generally have quite a bit of internal state. On the other hand, the parse trees generated by this parser are much smaller. It is also fairly cheap to traverse a parse tree in order to evaluate it. Thus it is usually preferable to cache parse trees and create a new parser when the cached parse tree becomes invalid. @author Neil Smyth, Steve Neuendorffer @version $Id: PtParser.java,v 1.143.4.1 2008/03/25 22:31:39 cxh Exp $ @since Ptolemy II 1.0 @Pt.ProposedRating Yellow (nsmyth) @Pt.AcceptedRating Yellow (yuhong) @see ptolemy.data.expr.ASTPtBitwiseNode @see ptolemy.data.expr.ASTPtFunctionApplicationNode @see ptolemy.data.expr.ASTPtFunctionDefinitionNode @see ptolemy.data.expr.ASTPtFunctionalIfNode @see ptolemy.data.expr.ASTPtLeafNode @see ptolemy.data.expr.ASTPtLogicalNode @see ptolemy.data.expr.ASTPtMethodCallNode @see ptolemy.data.expr.ASTPtProductNode @see ptolemy.data.expr.ASTPtRelationalNode @see ptolemy.data.expr.ASTPtRootNode @see ptolemy.data.expr.ASTPtSumNode @see ptolemy.data.expr.ASTPtUnaryNode @see ptolemy.data.Token

Examples of ptolemy.data.expr.PtParser

         *  the corresponding parameter.
         */
        public void assignNonPtalonParameters(ComponentEntity actor)
                throws PtalonRuntimeException {
            try {
                PtParser parser = new PtParser();
                ParseTreeEvaluator _parseTreeEvaluator = new ParseTreeEvaluator();
                for (String parameterName : _parameters.keySet()) {
                    String expression = _parameters.get(parameterName);
                    if (expression == null) {
                        throw new PtalonRuntimeException(
                                "Unable to find expression label for "
                                        + "parameter " + parameterName);
                    }
                    ASTPtRootNode parseTree = parser
                            .generateParseTree(expression);
                    try {
                        Parameter parameter = (Parameter) actor
                                .getAttribute(parameterName);
                        if (parameter == null) {

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Examples of ptolemy.data.expr.PtParser

            // below.
            if (_parseTree == null) {
                // Note that the parser is NOT retained, since in most
                // cases the expression doesn't change, and the parser
                // requires a large amount of memory.
                PtParser parser = new PtParser();
                _parseTree = parser.generateParseTree(expression
                        .getExpression());
            }


            if (_parseTreeEvaluator == null) {
                _parseTreeEvaluator = new ParseTreeEvaluator();

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Examples of ptolemy.data.expr.PtParser

                // code above.
                if (_parseTree == null) {
                    // Note that the parser is NOT retained, since in most
                    // cases the expression doesn't change, and the parser
                    // requires a large amount of memory.
                    PtParser parser = new PtParser();
                    _parseTree = parser.generateParseTree(expression
                            .getExpression());
                }


                if (_scope == null) {
                    _scope = new VariableScope();

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Examples of ptolemy.data.expr.PtParser

            // Return an array that contains type terms for all of the
            // inputs and all of the parameters that are free variables for
            // the expression.
            try {
                if (_parseTree == null) {
                    PtParser parser = new PtParser();
                    _parseTree = parser.generateParseTree(expression
                            .getExpression());
                }


                if (_scope == null) {
                    _scope = new VariableScope();

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Examples of ptolemy.data.expr.PtParser


            Transition transition = (Transition) transitions.next();


            // generate code for guard expression
            String guard = transition.getGuardExpression();
            PtParser parser = new PtParser();
            ASTPtRootNode guardParseTree = parser.generateParseTree(guard);
            ParseTreeCodeGenerator parseTreeCodeGenerator = controllerHelper
                    .getParseTreeCodeGenerator();
            parseTreeCodeGenerator.evaluateParseTree(guardParseTree,
                    controllerHelper._scope);
            codeBuffer.append(parseTreeCodeGenerator.generateFireCode());

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Examples of ptolemy.data.expr.PtParser

     *  <code>1.0+2.0i</code>.
     *  @exception IllegalActionException If the string does not represent
     *   a parsable complex number.
     */
    public ComplexToken(String init) throws IllegalActionException {
        PtParser parser = new PtParser();
        ASTPtRootNode tree = parser.generateParseTree(init);
        Token token = (new ParseTreeEvaluator()).evaluateParseTree(tree);


        if (token instanceof ComplexToken) {
            _value = ((ComplexToken) token).complexValue();
        } else {

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Examples of ptolemy.data.expr.PtParser

        // container are not free variables of this container.
        set.removeAll(variableNames);


        // Iterate over all the variables of this container, and add in
        // any free variables they reference.
        PtParser parser = new PtParser();
        ParseTreeFreeVariableCollector collector = new ParseTreeFreeVariableCollector();


        for (Iterator variables = model.attributeList(Variable.class)
                .iterator(); variables.hasNext();) {
            Variable variable = (Variable) variables.next();
            String expression = variable.getExpression();
            ASTPtRootNode root;


            if (variable.isStringMode()) {
                root = parser.generateStringParseTree(expression);
            } else {
                root = parser.generateParseTree(expression);
            }


            Set freeIdentifiers = new HashSet(collector
                    .collectFreeVariables(root));

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Examples of ptolemy.data.expr.PtParser

                                    .escapeForTargetLanguage(variable
                                            .getExpression()) + "\"", castType,
                            "String");
                }


                PtParser parser = new PtParser();
                ASTPtRootNode parseTree = null;
                try {
                    parseTree = parser.generateParseTree(variable
                            .getExpression());
                } catch (Throwable throwable) {
                    throw new IllegalActionException(variable, throwable,
                            "Failed to generate parse tree for \"" + name
                                    + "\". in \"" + container + "\"");

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Examples of ptolemy.data.expr.PtParser

     *  @param init A string expression of an array.
     *  @exception IllegalActionException If the string does
     *   not contain a parsable array.
     */
    public ArrayToken(String init) throws IllegalActionException {
        PtParser parser = new PtParser();
        ASTPtRootNode tree = parser.generateParseTree(init);
        ParseTreeEvaluator evaluator = new ParseTreeEvaluator();
        Token token = evaluator.evaluateParseTree(tree);


        if (token instanceof ArrayToken) {
            _value = ((ArrayToken) token)._value;

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Examples of ptolemy.data.expr.PtParser

     *  @param init A string expression of a boolean matrix.
     *  @exception IllegalActionException If the string does
     *   not contain a parsable boolean matrix.
     */
    public BooleanMatrixToken(String init) throws IllegalActionException {
        PtParser parser = new PtParser();
        ASTPtRootNode tree = parser.generateParseTree(init);
        Token token = (new ParseTreeEvaluator()).evaluateParseTree(tree);


        if (token instanceof BooleanMatrixToken) {
            boolean[][] value = ((BooleanMatrixToken) token).booleanMatrix();
            _initialize(value);

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