package antlr;
/* ANTLR Translator Generator
* Project led by Terence Parr at http://www.cs.usfca.edu
* Software rights: http://www.antlr.org/license.html
*
* $Id: //depot/code/org.antlr/release/antlr-2.7.6/antlr/RuleBlock.java#1 $
*/
import antlr.collections.impl.Vector;
import java.util.Hashtable;
/**A list of alternatives and info contained in
* the rule definition.
*/
public class RuleBlock extends AlternativeBlock {
protected String ruleName;
protected String argAction = null; // string for rule arguments [...]
protected String throwsSpec = null;
protected String returnAction = null;// string for rule return type(s) <...>
protected RuleEndElement endNode; // which node ends this rule?
// Generate literal-testing code for lexer rule?
protected boolean testLiterals = false;
Vector labeledElements; // List of labeled elements found in this rule
// This is a list of AlternativeElement (or subclass)
protected boolean[] lock; // for analysis; used to avoid infinite loops
// 1..k
protected Lookahead cache[];// Each rule can cache it's lookahead computation.
// This cache contains an epsilon
// imaginary token if the FOLLOW is required. No
// FOLLOW information is cached here.
// The FIRST(rule) is stored in this cache; 1..k
// This set includes FIRST of all alts.
Hashtable exceptionSpecs; // table of String-to-ExceptionSpec.
// grammar-settable options
protected boolean defaultErrorHandler = true;
protected String ignoreRule = null;
/** Construct a named rule. */
public RuleBlock(Grammar g, String r) {
super(g);
ruleName = r;
labeledElements = new Vector();
cache = new Lookahead[g.maxk + 1];
exceptionSpecs = new Hashtable();
setAutoGen(g instanceof ParserGrammar);
}
/** Construct a named rule with line number information */
public RuleBlock(Grammar g, String r, int line, boolean doAutoGen_) {
this(g, r);
this.line = line;
setAutoGen(doAutoGen_);
}
public void addExceptionSpec(ExceptionSpec ex) {
if (findExceptionSpec(ex.label) != null) {
if (ex.label != null) {
grammar.antlrTool.error("Rule '" + ruleName + "' already has an exception handler for label: " + ex.label);
}
else {
grammar.antlrTool.error("Rule '" + ruleName + "' already has an exception handler");
}
}
else {
exceptionSpecs.put((ex.label == null ? "" : ex.label.getText()), ex);
}
}
public ExceptionSpec findExceptionSpec(Token label) {
return (ExceptionSpec)exceptionSpecs.get(label == null ? "" : label.getText());
}
public ExceptionSpec findExceptionSpec(String label) {
return (ExceptionSpec)exceptionSpecs.get(label == null ? "" : label);
}
public void generate() {
grammar.generator.gen(this);
}
public boolean getDefaultErrorHandler() {
return defaultErrorHandler;
}
public RuleEndElement getEndElement() {
return endNode;
}
public String getIgnoreRule() {
return ignoreRule;
}
public String getRuleName() {
return ruleName;
}
public boolean getTestLiterals() {
return testLiterals;
}
public boolean isLexerAutoGenRule() {
return ruleName.equals("nextToken");
}
public Lookahead look(int k) {
return grammar.theLLkAnalyzer.look(k, this);
}
public void prepareForAnalysis() {
super.prepareForAnalysis();
lock = new boolean[grammar.maxk + 1];
}
// rule option values
public void setDefaultErrorHandler(boolean value) {
defaultErrorHandler = value;
}
public void setEndElement(RuleEndElement re) {
endNode = re;
}
public void setOption(Token key, Token value) {
if (key.getText().equals("defaultErrorHandler")) {
if (value.getText().equals("true")) {
defaultErrorHandler = true;
}
else if (value.getText().equals("false")) {
defaultErrorHandler = false;
}
else {
grammar.antlrTool.error("Value for defaultErrorHandler must be true or false", grammar.getFilename(), key.getLine(), key.getColumn());
}
}
else if (key.getText().equals("testLiterals")) {
if (!(grammar instanceof LexerGrammar)) {
grammar.antlrTool.error("testLiterals option only valid for lexer rules", grammar.getFilename(), key.getLine(), key.getColumn());
}
else {
if (value.getText().equals("true")) {
testLiterals = true;
}
else if (value.getText().equals("false")) {
testLiterals = false;
}
else {
grammar.antlrTool.error("Value for testLiterals must be true or false", grammar.getFilename(), key.getLine(), key.getColumn());
}
}
}
else if (key.getText().equals("ignore")) {
if (!(grammar instanceof LexerGrammar)) {
grammar.antlrTool.error("ignore option only valid for lexer rules", grammar.getFilename(), key.getLine(), key.getColumn());
}
else {
ignoreRule = value.getText();
}
}
else if (key.getText().equals("paraphrase")) {
if (!(grammar instanceof LexerGrammar)) {
grammar.antlrTool.error("paraphrase option only valid for lexer rules", grammar.getFilename(), key.getLine(), key.getColumn());
}
else {
// find token def associated with this rule
TokenSymbol ts = grammar.tokenManager.getTokenSymbol(ruleName);
if (ts == null) {
grammar.antlrTool.panic("cannot find token associated with rule " + ruleName);
}
ts.setParaphrase(value.getText());
}
}
else if (key.getText().equals("generateAmbigWarnings")) {
if (value.getText().equals("true")) {
generateAmbigWarnings = true;
}
else if (value.getText().equals("false")) {
generateAmbigWarnings = false;
}
else {
grammar.antlrTool.error("Value for generateAmbigWarnings must be true or false", grammar.getFilename(), key.getLine(), key.getColumn());
}
}
else {
grammar.antlrTool.error("Invalid rule option: " + key.getText(), grammar.getFilename(), key.getLine(), key.getColumn());
}
}
public String toString() {
String s = " FOLLOW={";
Lookahead cache[] = endNode.cache;
int k = grammar.maxk;
boolean allNull = true;
for (int j = 1; j <= k; j++) {
if (cache[j] == null) continue;
s += cache[j].toString(",", grammar.tokenManager.getVocabulary());
allNull = false;
if (j < k && cache[j + 1] != null) s += ";";
}
s += "}";
if (allNull) s = "";
return ruleName + ": " + super.toString() + " ;" + s;
}
}