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

        public void setIterationCount(String expression) {
            _expression = expression;


            // FIXME: Need better exception handling.
            try {
                PtParser parser = new PtParser();
                _parseTree = parser.generateParseTree(expression);
            } catch (Exception exception) {
                throw new RuntimeException("Error setting iteration count to "
                        + expression + ".\n" + exception.getMessage());
            }
        }

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Examples of ptolemy.data.expr.PtParser

    public void getOutputActionsReferredInputPorts(Transition transition)
            throws IllegalActionException {
        _outputActionReferredInputPorts.clear();


        String string = transition.outputActions.getExpression();
        PtParser parser = new PtParser();
        ASTPtRootNode parseTree;
        ParseTreeFreeVariableCollector variableCollector = new ParseTreeFreeVariableCollector();
        FSMActor controller = getController();
        ParserScope scope = controller.getPortScope();


        if (!string.equals("")) {
            Map map = parser.generateAssignmentMap(string);
            Set set /* Dead Local Store: = new HashSet()*/;


            for (Iterator names = map.keySet().iterator(); names.hasNext();) {
                String name = (String) names.next();

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Examples of ptolemy.data.expr.PtParser

    public void getSetActionsReferredInputPorts(Transition transition)
            throws IllegalActionException {
        _setActionReferredInputPorts.clear();


        String string = transition.setActions.getExpression();
        PtParser parser = new PtParser();
        ASTPtRootNode parseTree;
        ParseTreeFreeVariableCollector variableCollector = new ParseTreeFreeVariableCollector();
        FSMActor controller = getController();
        ParserScope scope = controller.getPortScope();


        if (!string.equals("")) {
            Map map = parser.generateAssignmentMap(string);
            Set set /* Dead Local Store: = new HashSet()*/;


            for (Iterator names = map.keySet().iterator(); names.hasNext();) {
                String name = (String) names.next();

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Examples of ptolemy.data.expr.PtParser

            if (string.equals("")) {
                throw new IllegalActionException(this, "guard expression on "
                        + transition.getName() + "is null!");
            }


            PtParser parser = new PtParser();
            ASTPtRootNode parseTree = parser.generateParseTree(string);
            ParseTreeFreeVariableCollector variableCollector = new ParseTreeFreeVariableCollector();
            FSMActor controller = getController();
            ParserScope scope = controller.getPortScope();
            Set set = variableCollector.collectFreeVariables(parseTree, scope);
            getReferredInputPorts(set, transitionsReferredInputPorts);

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Examples of ptolemy.data.expr.PtParser

        public void setIterationCount(String expression) {
            _expression = expression;


            // FIXME: Need better exception handling.
            try {
                PtParser parser = new PtParser();
                _parseTree = parser.generateParseTree(expression);
            } catch (Exception exception) {
                throw new RuntimeException("Error setting iteration count to "
                        + expression + ".\n" + exception.getMessage());
            }
        }

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Examples of ptolemy.data.expr.PtParser

        // this class.
        if ((expression == null) || expression.trim().equals("")) {
            return;
        }


        PtParser parser = new PtParser();
        Map map = parser.generateAssignmentMap(expression);


        for (Iterator names = map.keySet().iterator(); names.hasNext();) {
            String name = (String) names.next();
            ASTPtAssignmentNode node = (ASTPtAssignmentNode) map.get(name);

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Examples of ptolemy.data.expr.PtParser

        ParseTreeEvaluator parseTreeEvaluator = getParseTreeEvaluator();
        FSMActor fsmActor = (FSMActor) getContainer();
        if (_guardParseTree == null) {
            String expr = getGuardExpression();
            // Parse the guard expression.
            PtParser parser = new PtParser();
            try {
                _guardParseTree = parser.generateParseTree(expr);
            } catch (IllegalActionException ex) {
                throw new IllegalActionException(this, ex,
                        "Failed to parse guard expression \"" + expr + "\"");
            }
        }

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Examples of ptolemy.data.expr.PtParser

     *  @param init A string expression of a record.
     *  @exception IllegalActionException If the string does not
     *  contain a parsable record.
     */
    public RecordToken(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 RecordToken) {

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Examples of ptolemy.data.expr.PtParser

     *  @param init A string expression of a record.
     *  @exception IllegalActionException If the string does not
     *  contain a parsable record.
     */
    public UnionToken(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 UnionToken) {

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Examples of ptolemy.data.expr.PtParser

    public String evaluateCommand(String command) throws Exception {
        if (command.trim().equals("")) {
            return "";
        }


        PtParser parser = new PtParser();
        ASTPtRootNode node = parser.generateSimpleAssignmentParseTree(command);
        String targetName = null;


        // Figure out if we got an assignment... if so, then get the
        // identifier name and only evaluated the expression part.
        if (node instanceof ASTPtAssignmentNode) {

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