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DiagnosticCodeGenerator.javaAPI DocGlassfish v2 API32508Wed Aug 30 15:34:06 BST 2006persistence.antlr

DiagnosticCodeGenerator.java

package persistence.antlr;

/* ANTLR Translator Generator
 * Project led by Terence Parr at http://www.jGuru.com
 * Software rights: http://www.antlr.org/license.html
 *
 */

import java.util.Enumeration;

import persistence.antlr.collections.impl.BitSet;
import persistence.antlr.collections.impl.Vector;

import java.io.PrintWriter; //SAS: changed for proper text file io
import java.io.IOException;
import java.io.FileWriter;

/**Generate MyParser.txt, MyLexer.txt and MyParserTokenTypes.txt */
public class DiagnosticCodeGenerator extends CodeGenerator {
    /** non-zero if inside syntactic predicate generation */
    protected int syntacticPredLevel = 0;

    /** true during lexer generation, false during parser generation */
    protected boolean doingLexRules = false;

    /** Create a Diagnostic code-generator using the given Grammar
     * The caller must still call setTool, setBehavior, and setAnalyzer
     * before generating code.
     */
    public DiagnosticCodeGenerator() {
        super();
        charFormatter = new JavaCharFormatter();
    }

    /**Generate the parser, lexer, and token types documentation */
    public void gen() {

        // Do the code generation
        try {
            // Loop over all grammars
            Enumeration grammarIter = behavior.grammars.elements();
            while (grammarIter.hasMoreElements()) {
                Grammar g = (Grammar)grammarIter.nextElement();

                // Connect all the components to each other
                g.setGrammarAnalyzer(analyzer);
                g.setCodeGenerator(this);
                analyzer.setGrammar(g);

                // To get right overloading behavior across hetrogeneous grammars
                g.generate();

                if (antlrTool.hasError()) {
                    antlrTool.panic("Exiting due to errors.");
                }

            }

            // Loop over all token managers (some of which are lexers)
            Enumeration tmIter = behavior.tokenManagers.elements();
            while (tmIter.hasMoreElements()) {
                TokenManager tm = (TokenManager)tmIter.nextElement();
                if (!tm.isReadOnly()) {
                    // Write the token manager tokens as Java
                    genTokenTypes(tm);
                }
            }
        }
        catch (IOException e) {
            antlrTool.reportException(e, null);
        }
    }

    /** Generate code for the given grammar element.
     * @param blk The {...} action to generate
     */
    public void gen(ActionElement action) {
        if (action.isSemPred) {
            // handled elsewhere
        }
        else {
            print("ACTION: ");
            _printAction(action.actionText);
        }
    }

    /** Generate code for the given grammar element.
     * @param blk The "x|y|z|..." block to generate
     */
    public void gen(AlternativeBlock blk) {
        println("Start of alternative block.");
        tabs++;
        genBlockPreamble(blk);

        boolean ok = grammar.theLLkAnalyzer.deterministic(blk);
        if (!ok) {
            println("Warning: This alternative block is non-deterministic");
        }
        genCommonBlock(blk);
        tabs--;
    }

    /** Generate code for the given grammar element.
     * @param blk The block-end element to generate.  Block-end
     * elements are synthesized by the grammar parser to represent
     * the end of a block.
     */
    public void gen(BlockEndElement end) {
        // no-op
    }

    /** Generate code for the given grammar element.
     * @param blk The character literal reference to generate
     */
    public void gen(CharLiteralElement atom) {
        print("Match character ");
        if (atom.not) {
            _print("NOT ");
        }
        _print(atom.atomText);
        if (atom.label != null) {
            _print(", label=" + atom.label);
        }
        _println("");
    }

    /** Generate code for the given grammar element.
     * @param blk The character-range reference to generate
     */
    public void gen(CharRangeElement r) {
        print("Match character range: " + r.beginText + ".." + r.endText);
        if (r.label != null) {
            _print(", label = " + r.label);
        }
        _println("");
    }

    /** Generate the lexer TXT file */
    public void gen(LexerGrammar g) throws IOException {
        setGrammar(g);
        antlrTool.reportProgress("Generating " + grammar.getClassName() + TokenTypesFileExt);
        currentOutput = antlrTool.openOutputFile(grammar.getClassName() + TokenTypesFileExt);
        //SAS: changed for proper text file io

        tabs = 0;
        doingLexRules = true;

        // Generate header common to all TXT output files
        genHeader();

        // Output the user-defined lexer premamble
        println("");
        println("*** Lexer Preamble Action.");
        println("This action will appear before the declaration of your lexer class:");
        tabs++;
        println(grammar.preambleAction.getText());
        tabs--;
        println("*** End of Lexer Preamble Action");

        // Generate lexer class definition
        println("");
        println("*** Your lexer class is called '" + grammar.getClassName() + "' and is a subclass of '" + grammar.getSuperClass() + "'.");

        // Generate user-defined parser class members
        println("");
        println("*** User-defined lexer  class members:");
        println("These are the member declarations that you defined for your class:");
        tabs++;
        printAction(grammar.classMemberAction.getText());
        tabs--;
        println("*** End of user-defined lexer class members");

        // Generate string literals
        println("");
        println("*** String literals used in the parser");
        println("The following string literals were used in the parser.");
        println("An actual code generator would arrange to place these literals");
        println("into a table in the generated lexer, so that actions in the");
        println("generated lexer could match token text against the literals.");
        println("String literals used in the lexer are not listed here, as they");
        println("are incorporated into the mainstream lexer processing.");
        tabs++;
        // Enumerate all of the symbols and look for string literal symbols
        Enumeration ids = grammar.getSymbols();
        while (ids.hasMoreElements()) {
            GrammarSymbol sym = (GrammarSymbol)ids.nextElement();
            // Only processing string literals -- reject other symbol entries
            if (sym instanceof StringLiteralSymbol) {
                StringLiteralSymbol s = (StringLiteralSymbol)sym;
                println(s.getId() + " = " + s.getTokenType());
            }
        }
        tabs--;
        println("*** End of string literals used by the parser");

        // Generate nextToken() rule.
        // nextToken() is a synthetic lexer rule that is the implicit OR of all
        // user-defined lexer rules.
        genNextToken();

        // Generate code for each rule in the lexer
        println("");
        println("*** User-defined Lexer rules:");
        tabs++;

        ids = grammar.rules.elements();
        while (ids.hasMoreElements()) {
            RuleSymbol rs = (RuleSymbol)ids.nextElement();
            if (!rs.id.equals("mnextToken")) {
                genRule(rs);
            }
        }

        tabs--;
        println("");
        println("*** End User-defined Lexer rules:");

        // Close the lexer output file
        currentOutput.close();
        currentOutput = null;
        doingLexRules = false;
    }

    /** Generate code for the given grammar element.
     * @param blk The (...)+ block to generate
     */
    public void gen(OneOrMoreBlock blk) {
        println("Start ONE-OR-MORE (...)+ block:");
        tabs++;
        genBlockPreamble(blk);
        boolean ok = grammar.theLLkAnalyzer.deterministic(blk);
        if (!ok) {
            println("Warning: This one-or-more block is non-deterministic");
        }
        genCommonBlock(blk);
        tabs--;
        println("End ONE-OR-MORE block.");
    }

    /** Generate the parser TXT file */
    public void gen(ParserGrammar g) throws IOException {
        setGrammar(g);
        // Open the output stream for the parser and set the currentOutput
        antlrTool.reportProgress("Generating " + grammar.getClassName() + TokenTypesFileExt);
        currentOutput = antlrTool.openOutputFile(grammar.getClassName() + TokenTypesFileExt);
        //SAS: changed for proper text file io

        tabs = 0;

        // Generate the header common to all output files.
        genHeader();

        // Output the user-defined parser premamble
        println("");
        println("*** Parser Preamble Action.");
        println("This action will appear before the declaration of your parser class:");
        tabs++;
        println(grammar.preambleAction.getText());
        tabs--;
        println("*** End of Parser Preamble Action");

        // Generate parser class definition
        println("");
        println("*** Your parser class is called '" + grammar.getClassName() + "' and is a subclass of '" + grammar.getSuperClass() + "'.");

        // Generate user-defined parser class members
        println("");
        println("*** User-defined parser class members:");
        println("These are the member declarations that you defined for your class:");
        tabs++;
        printAction(grammar.classMemberAction.getText());
        tabs--;
        println("*** End of user-defined parser class members");

        // Generate code for each rule in the grammar
        println("");
        println("*** Parser rules:");
        tabs++;

        // Enumerate the parser rules
        Enumeration rules = grammar.rules.elements();
        while (rules.hasMoreElements()) {
            println("");
            // Get the rules from the list and downcast it to proper type
            GrammarSymbol sym = (GrammarSymbol)rules.nextElement();
            // Only process parser rules
            if (sym instanceof RuleSymbol) {
                genRule((RuleSymbol)sym);
            }
        }
        tabs--;
        println("");
        println("*** End of parser rules");

        println("");
        println("*** End of parser");

        // Close the parser output stream
        currentOutput.close();
        currentOutput = null;
    }

    /** Generate code for the given grammar element.
     * @param blk The rule-reference to generate
     */
    public void gen(RuleRefElement rr) {
        RuleSymbol rs = (RuleSymbol)grammar.getSymbol(rr.targetRule);

        // Generate the actual rule description
        print("Rule Reference: " + rr.targetRule);
        if (rr.idAssign != null) {
            _print(", assigned to '" + rr.idAssign + "'");
        }
        if (rr.args != null) {
            _print(", arguments = " + rr.args);
        }
        _println("");

        // Perform diagnostics
        if (rs == null || !rs.isDefined()) {
            println("Rule '" + rr.targetRule + "' is referenced, but that rule is not defined.");
            println("\tPerhaps the rule is misspelled, or you forgot to define it.");
            return;
        }
        if (!(rs instanceof RuleSymbol)) {
            // Should this ever happen??
            println("Rule '" + rr.targetRule + "' is referenced, but that is not a grammar rule.");
            return;
        }
        if (rr.idAssign != null) {
            // Warn if the rule has no return type
            if (rs.block.returnAction == null) {
                println("Error: You assigned from Rule '" + rr.targetRule + "', but that rule has no return type.");
            }
        }
        else {
            // Warn about return value if any, but not inside syntactic predicate
            if (!(grammar instanceof LexerGrammar) && syntacticPredLevel == 0 && rs.block.returnAction != null) {
                println("Warning: Rule '" + rr.targetRule + "' returns a value");
            }
        }
        if (rr.args != null && rs.block.argAction == null) {
            println("Error: Rule '" + rr.targetRule + "' accepts no arguments.");
        }
    }

    /** Generate code for the given grammar element.
     * @param blk The string-literal reference to generate
     */
    public void gen(StringLiteralElement atom) {
        print("Match string literal ");
        _print(atom.atomText);
        if (atom.label != null) {
            _print(", label=" + atom.label);
        }
        _println("");
    }

    /** Generate code for the given grammar element.
     * @param blk The token-range reference to generate
     */
    public void gen(TokenRangeElement r) {
        print("Match token range: " + r.beginText + ".." + r.endText);
        if (r.label != null) {
            _print(", label = " + r.label);
        }
        _println("");
    }

    /** Generate code for the given grammar element.
     * @param blk The token-reference to generate
     */
    public void gen(TokenRefElement atom) {
        print("Match token ");
        if (atom.not) {
            _print("NOT ");
        }
        _print(atom.atomText);
        if (atom.label != null) {
            _print(", label=" + atom.label);
        }
        _println("");
    }

    public void gen(TreeElement t) {
        print("Tree reference: " + t);
    }

    /** Generate the tree-walker TXT file */
    public void gen(TreeWalkerGrammar g) throws IOException {
        setGrammar(g);
        // Open the output stream for the parser and set the currentOutput
        antlrTool.reportProgress("Generating " + grammar.getClassName() + TokenTypesFileExt);
        currentOutput = antlrTool.openOutputFile(grammar.getClassName() + TokenTypesFileExt);
        //SAS: changed for proper text file io

        tabs = 0;

        // Generate the header common to all output files.
        genHeader();

        // Output the user-defined parser premamble
        println("");
        println("*** Tree-walker Preamble Action.");
        println("This action will appear before the declaration of your tree-walker class:");
        tabs++;
        println(grammar.preambleAction.getText());
        tabs--;
        println("*** End of tree-walker Preamble Action");

        // Generate tree-walker class definition
        println("");
        println("*** Your tree-walker class is called '" + grammar.getClassName() + "' and is a subclass of '" + grammar.getSuperClass() + "'.");

        // Generate user-defined tree-walker class members
        println("");
        println("*** User-defined tree-walker class members:");
        println("These are the member declarations that you defined for your class:");
        tabs++;
        printAction(grammar.classMemberAction.getText());
        tabs--;
        println("*** End of user-defined tree-walker class members");

        // Generate code for each rule in the grammar
        println("");
        println("*** tree-walker rules:");
        tabs++;

        // Enumerate the tree-walker rules
        Enumeration rules = grammar.rules.elements();
        while (rules.hasMoreElements()) {
            println("");
            // Get the rules from the list and downcast it to proper type
            GrammarSymbol sym = (GrammarSymbol)rules.nextElement();
            // Only process tree-walker rules
            if (sym instanceof RuleSymbol) {
                genRule((RuleSymbol)sym);
            }
        }
        tabs--;
        println("");
        println("*** End of tree-walker rules");

        println("");
        println("*** End of tree-walker");

        // Close the tree-walker output stream
        currentOutput.close();
        currentOutput = null;
    }

    /** Generate a wildcard element */
    public void gen(WildcardElement wc) {
        print("Match wildcard");
        if (wc.getLabel() != null) {
            _print(", label = " + wc.getLabel());
        }
        _println("");
    }

    /** Generate code for the given grammar element.
     * @param blk The (...)* block to generate
     */
    public void gen(ZeroOrMoreBlock blk) {
        println("Start ZERO-OR-MORE (...)+ block:");
        tabs++;
        genBlockPreamble(blk);
        boolean ok = grammar.theLLkAnalyzer.deterministic(blk);
        if (!ok) {
            println("Warning: This zero-or-more block is non-deterministic");
        }
        genCommonBlock(blk);
        tabs--;
        println("End ZERO-OR-MORE block.");
    }

    protected void genAlt(Alternative alt) {
        for (
            AlternativeElement elem = alt.head;
            !(elem instanceof BlockEndElement);
            elem = elem.next
            ) {
            elem.generate();
        }
        if (alt.getTreeSpecifier() != null) {
            println("AST will be built as: " + alt.getTreeSpecifier().getText());
        }
    }

    /** Generate the header for a block, which may be a RuleBlock or a
     * plain AlternativeBLock.  This generates any variable declarations,
     * init-actions, and syntactic-predicate-testing variables.
     * @blk The block for which the preamble is to be generated.
     */
    protected void genBlockPreamble(AlternativeBlock blk) {
        // dump out init action
        if (blk.initAction != null) {
            printAction("Init action: " + blk.initAction);
        }
    }

    /**Generate common code for a block of alternatives; return a postscript
     * that needs to be generated at the end of the block.  Other routines
     * may append else-clauses and such for error checking before the postfix
     * is generated.
     */
    public void genCommonBlock(AlternativeBlock blk) {
        boolean singleAlt = (blk.alternatives.size() == 1);

        println("Start of an alternative block.");
        tabs++;
        println("The lookahead set for this block is:");
        tabs++;
        genLookaheadSetForBlock(blk);
        tabs--;

        if (singleAlt) {
            println("This block has a single alternative");
            if (blk.getAlternativeAt(0).synPred != null) {
                // Generate a warning if there is one alt and it has a synPred
                println("Warning: you specified a syntactic predicate for this alternative,");
                println("and it is the only alternative of a block and will be ignored.");
            }
        }
        else {
            println("This block has multiple alternatives:");
            tabs++;
        }

        for (int i = 0; i < blk.alternatives.size(); i++) {
            Alternative alt = blk.getAlternativeAt(i);
            AlternativeElement elem = alt.head;

            // Print lookahead set for alternate
            println("");
            if (i != 0) {
                print("Otherwise, ");
            }
            else {
                print("");
            }
            _println("Alternate(" + (i + 1) + ") will be taken IF:");
            println("The lookahead set: ");
            tabs++;
            genLookaheadSetForAlt(alt);
            tabs--;
            if (alt.semPred != null || alt.synPred != null) {
                print("is matched, AND ");
            }
            else {
                println("is matched.");
            }

            // Dump semantic predicates
            if (alt.semPred != null) {
                _println("the semantic predicate:");
                tabs++;
                println(alt.semPred);
                if (alt.synPred != null) {
                    print("is true, AND ");
                }
                else {
                    println("is true.");
                }
            }

            // Dump syntactic predicate
            if (alt.synPred != null) {
                _println("the syntactic predicate:");
                tabs++;
                genSynPred(alt.synPred);
                tabs--;
                println("is matched.");
            }

            // Dump the alternative
            genAlt(alt);
        }
        println("");
        println("OTHERWISE, a NoViableAlt exception will be thrown");
        println("");

        if (!singleAlt) {
            tabs--;
            println("End of alternatives");
        }
        tabs--;
        println("End of alternative block.");
    }

    /** Generate a textual representation of the follow set
     * for a block.
     * @param blk  The rule block of interest
     */
    public void genFollowSetForRuleBlock(RuleBlock blk) {
        Lookahead follow = grammar.theLLkAnalyzer.FOLLOW(1, blk.endNode);
        printSet(grammar.maxk, 1, follow);
    }

    /** Generate a header that is common to all TXT files */
    protected void genHeader() {
        println("ANTLR-generated file resulting from grammar " + antlrTool.grammarFile);
        println("Diagnostic output");
        println("");
        println("Terence Parr, MageLang Institute");
        println("with John Lilley, Empathy Software");
        println("ANTLR Version " + antlrTool.version + "; 1996,1997");
        println("");
        println("*** Header Action.");
        println("This action will appear at the top of all generated files.");
        tabs++;
        printAction(behavior.getHeaderAction(""));
        tabs--;
        println("*** End of Header Action");
        println("");
    }

    /**Generate the lookahead set for an alternate. */
    protected void genLookaheadSetForAlt(Alternative alt) {
        if (doingLexRules && alt.cache[1].containsEpsilon()) {
            println("MATCHES ALL");
            return;
        }
        int depth = alt.lookaheadDepth;
        if (depth == GrammarAnalyzer.NONDETERMINISTIC) {
            // if the decision is nondeterministic, do the best we can: LL(k)
            // any predicates that are around will be generated later.
            depth = grammar.maxk;
        }
        for (int i = 1; i <= depth; i++) {
            Lookahead lookahead = alt.cache[i];
            printSet(depth, i, lookahead);
        }
    }

    /** Generate a textual representation of the lookahead set
     * for a block.
     * @param blk  The block of interest
     */
    public void genLookaheadSetForBlock(AlternativeBlock blk) {
        // Find the maximal lookahead depth over all alternatives
        int depth = 0;
        for (int i = 0; i < blk.alternatives.size(); i++) {
            Alternative alt = blk.getAlternativeAt(i);
            if (alt.lookaheadDepth == GrammarAnalyzer.NONDETERMINISTIC) {
                depth = grammar.maxk;
                break;
            }
            else if (depth < alt.lookaheadDepth) {
                depth = alt.lookaheadDepth;
            }
        }

        for (int i = 1; i <= depth; i++) {
            Lookahead lookahead = grammar.theLLkAnalyzer.look(i, blk);
            printSet(depth, i, lookahead);
        }
    }

    /** Generate the nextToken rule.
     * nextToken is a synthetic lexer rule that is the implicit OR of all
     * user-defined lexer rules.
     */
    public void genNextToken() {
        println("");
        println("*** Lexer nextToken rule:");
        println("The lexer nextToken rule is synthesized from all of the user-defined");
        println("lexer rules.  It logically consists of one big alternative block with");
        println("each user-defined rule being an alternative.");
        println("");

        // Create the synthesized rule block for nextToken consisting
        // of an alternate block containing all the user-defined lexer rules.
        RuleBlock blk = MakeGrammar.createNextTokenRule(grammar, grammar.rules, "nextToken");

        // Define the nextToken rule symbol
        RuleSymbol nextTokenRs = new RuleSymbol("mnextToken");
        nextTokenRs.setDefined();
        nextTokenRs.setBlock(blk);
        nextTokenRs.access = "private";
        grammar.define(nextTokenRs);

        // Analyze the synthesized block
        if (!grammar.theLLkAnalyzer.deterministic(blk)) {
            println("The grammar analyzer has determined that the synthesized");
            println("nextToken rule is non-deterministic (i.e., it has ambiguities)");
            println("This means that there is some overlap of the character");
            println("lookahead for two or more of your lexer rules.");
        }

        genCommonBlock(blk);

        println("*** End of nextToken lexer rule.");
    }

    /** Generate code for a named rule block
     * @param s The RuleSymbol describing the rule to generate
     */
    public void genRule(RuleSymbol s) {
        println("");
        String ruleType = (doingLexRules ? "Lexer" : "Parser");
        println("*** " + ruleType + " Rule: " + s.getId());
        if (!s.isDefined()) {
            println("This rule is undefined.");
            println("This means that the rule was referenced somewhere in the grammar,");
            println("but a definition for the rule was not encountered.");
            println("It is also possible that syntax errors during the parse of");
            println("your grammar file prevented correct processing of the rule.");
            println("*** End " + ruleType + " Rule: " + s.getId());
            return;
        }
        tabs++;

        if (s.access.length() != 0) {
            println("Access: " + s.access);
        }

        // Get rule return type and arguments
        RuleBlock rblk = s.getBlock();

        // Gen method return value(s)
        if (rblk.returnAction != null) {
            println("Return value(s): " + rblk.returnAction);
            if (doingLexRules) {
                println("Error: you specified return value(s) for a lexical rule.");
                println("\tLexical rules have an implicit return type of 'int'.");
            }
        }
        else {
            if (doingLexRules) {
                println("Return value: lexical rule returns an implicit token type");
            }
            else {
                println("Return value: none");
            }
        }

        // Gen arguments
        if (rblk.argAction != null) {
            println("Arguments: " + rblk.argAction);
        }

        // Dump any init-action
        genBlockPreamble(rblk);

        // Analyze the rule
        boolean ok = grammar.theLLkAnalyzer.deterministic(rblk);
        if (!ok) {
            println("Error: This rule is non-deterministic");
        }

        // Dump the alternates of the rule
        genCommonBlock(rblk);

        // Search for an unlabeled exception specification attached to the rule
        ExceptionSpec unlabeledUserSpec = rblk.findExceptionSpec("");

        // Generate user-defined or default catch phrases
        if (unlabeledUserSpec != null) {
            println("You specified error-handler(s) for this rule:");
            tabs++;
            for (int i = 0; i < unlabeledUserSpec.handlers.size(); i++) {
                if (i != 0) {
                    println("");
                }

                ExceptionHandler handler = (ExceptionHandler)unlabeledUserSpec.handlers.elementAt(i);
                println("Error-handler(" + (i + 1) + ") catches [" + handler.exceptionTypeAndName.getText() + "] and executes:");
                printAction(handler.action.getText());
            }
            tabs--;
            println("End error-handlers.");
        }
        else if (!doingLexRules) {
            println("Default error-handling will be generated, which catches all");
            println("parser exceptions and consumes tokens until the follow-set is seen.");
        }

        // Dump the follow set
        // Doesn't seem to work for lexical rules...
        if (!doingLexRules) {
            println("The follow set for this rule is:");
            tabs++;
            genFollowSetForRuleBlock(rblk);
            tabs--;
        }

        tabs--;
        println("*** End " + ruleType + " Rule: " + s.getId());
    }

    /** Generate the syntactic predicate.  This basically generates
     * the alternative block, buts tracks if we are inside a synPred
     * @param blk  The syntactic predicate block
     */
    protected void genSynPred(SynPredBlock blk) {
        syntacticPredLevel++;
        gen((AlternativeBlock)blk);
        syntacticPredLevel--;
    }

    /** Generate the token types TXT file */
    protected void genTokenTypes(TokenManager tm) throws IOException {
        // Open the token output TXT file and set the currentOutput stream
        antlrTool.reportProgress("Generating " + tm.getName() + TokenTypesFileSuffix + TokenTypesFileExt);
        currentOutput = antlrTool.openOutputFile(tm.getName() + TokenTypesFileSuffix + TokenTypesFileExt);
        //SAS: changed for proper text file io
        tabs = 0;

        // Generate the header common to all diagnostic files
        genHeader();

        // Generate a string for each token.  This creates a static
        // array of Strings indexed by token type.
        println("");
        println("*** Tokens used by the parser");
        println("This is a list of the token numeric values and the corresponding");
        println("token identifiers.  Some tokens are literals, and because of that");
        println("they have no identifiers.  Literals are double-quoted.");
        tabs++;

        // Enumerate all the valid token types
        Vector v = tm.getVocabulary();
        for (int i = Token.MIN_USER_TYPE; i < v.size(); i++) {
            String s = (String)v.elementAt(i);
            if (s != null) {
                println(s + " = " + i);
            }
        }

        // Close the interface
        tabs--;
        println("*** End of tokens used by the parser");

        // Close the tokens output file
        currentOutput.close();
        currentOutput = null;
    }

    /** Get a string for an expression to generate creation of an AST subtree.
     * @param v A Vector of String, where each element is an expression in the target language yielding an AST node.
     */
    public String getASTCreateString(Vector v) {
        return "***Create an AST from a vector here***" + System.getProperty("line.separator");
    }

    /** Get a string for an expression to generate creating of an AST node
     * @param str The arguments to the AST constructor
     */
    public String getASTCreateString(GrammarAtom atom, String str) {
        return "[" + str + "]";
    }

    /// unused.
    protected String processActionForSpecialSymbols(String actionStr,
                                                    int line,
                                                    RuleBlock currentRule,
                                                    ActionTransInfo tInfo) {
        return actionStr;
    }

    /** Map an identifier to it's corresponding tree-node variable.
     * This is context-sensitive, depending on the rule and alternative
     * being generated
     * @param id The identifier name to map
     * @param forInput true if the input tree node variable is to be returned, otherwise the output variable is returned.
     */
    public String mapTreeId(String id, ActionTransInfo tInfo) {
        return id;
    }

    /** Format a lookahead or follow set.
     * @param depth The depth of the entire lookahead/follow
     * @param k The lookahead level to print
     * @param lookahead  The lookahead/follow set to print
     */
    public void printSet(int depth, int k, Lookahead lookahead) {
        int numCols = 5;

        int[] elems = lookahead.fset.toArray();

        if (depth != 1) {
            print("k==" + k + ": {");
        }
        else {
            print("{ ");
        }
        if (elems.length > numCols) {
            _println("");
            tabs++;
            print("");
        }

        int column = 0;
        for (int i = 0; i < elems.length; i++) {
            column++;
            if (column > numCols) {
                _println("");
                print("");
                column = 0;
            }
            if (doingLexRules) {
                _print(charFormatter.literalChar(elems[i]));
            }
            else {
                _print((String)grammar.tokenManager.getVocabulary().elementAt(elems[i]));
            }
            if (i != elems.length - 1) {
                _print(", ");
            }
        }

        if (elems.length > numCols) {
            _println("");
            tabs--;
            print("");
        }
        _println(" }");
    }
}