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removed alt as unnecessary arg to LOOK in linear approximator; added FOLLOW computation 

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 6848]
This commit is contained in:
parrt 2010-05-08 15:35:03 -08:00
parent 3b7b45787a
commit d822cb8b23
3 changed files with 60 additions and 15 deletions
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2
tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
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@ -34,7 +34,7 @@ switch ( input.LA(1) ) {
>>
matchToken(m) ::= <<
match(<m.ttype>);
match(<m.name>);
>>
codeFileExtension() ::= ".java"

62
tool/src/org/antlr/v4/analysis/LinearApproximator.java
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@ -66,11 +66,13 @@ public class LinearApproximator {
OrderedHashSet<NFAConfig>[] configs;
public LinearApproximator(Grammar g, int decision) {
this.g = g; this.decision = decision;
this.g = g;
this.decision = decision;
}
public LinearApproximator(Grammar g, int decision, int k) {
this(g,decision); max_k = k;
this(g,decision);
max_k = k;
}
public DFA createDFA(DecisionState s) {
@ -85,7 +87,7 @@ public class LinearApproximator {
// COLLECT LOOKAHEAD 1..k
for (int i=0; i<s.getNumberOfTransitions(); i++) {
Transition t = s.transition(i);
LOOK(t.target, i+1, MAX_LINEAR_APPROXIMATE_DEPTH);
LOOK(t.target, MAX_LINEAR_APPROXIMATE_DEPTH);
altLook.add(look.clone());
altConfigs.add(configs.clone());
// for (int k=1; k<=MAX_LINEAR_APPROXIMATE_DEPTH; k++) {
@ -155,7 +157,7 @@ public class LinearApproximator {
/** From an NFA state, s, find the set of all labels reachable from s at
* depth k.
*/
public IntervalSet[] LOOK(NFAState s, int alt, int k) {
public IntervalSet[] LOOK(NFAState s, int k) {
System.out.println("LOOK("+s.stateNumber+", "+k+")");
lookBusy.clear();
for (int i=1; i<=max_k; i++) { // init / reset work arrays
@ -163,18 +165,18 @@ public class LinearApproximator {
configs[i] = new OrderedHashSet<NFAConfig>();
}
_LOOK(s, alt, k, NFAContext.EMPTY());
_LOOK(s, k, NFAContext.EMPTY());
return look;
}
void _LOOK(NFAState s, int alt, int k, NFAContext context) {
void _LOOK(NFAState s, int k, NFAContext context) {
//System.out.println("_LOOK("+s.stateNumber+", "+k+", ctx="+context);
LookaheadNFAConfig ac = new LookaheadNFAConfig(s,k,context);
if ( lookBusy.contains(ac) ) return;
lookBusy.add(ac);
if ( s instanceof RuleStopState && !context.isEmpty() ) {
_LOOK(context.returnState, alt, k, context.parent);
_LOOK(context.returnState, k, context.parent);
return;
}
@ -184,18 +186,54 @@ public class LinearApproximator {
if ( t instanceof RuleTransition ) {
NFAContext newContext =
new NFAContext(context, ((RuleTransition)t).followState);
_LOOK(t.target, alt, k, newContext);
_LOOK(t.target, k, newContext);
}
else if ( t.isEpsilon() ) {
_LOOK(t.target, alt, k, context);
_LOOK(t.target, k, context);
}
else {
//System.out.println("adding "+ t.label().toString(g) +" @ i="+(MAX_K-k+1));
System.out.println("adding "+ t.label().toString(g) +" @ i="+(max_k-k+1));
look[max_k-k+1].addAll( t.label() );
NFAConfig c = new NFAConfig(t.target, alt, context,
NFAConfig c = new NFAConfig(t.target, 0, context,
SemanticContext.EMPTY_SEMANTIC_CONTEXT);
configs[max_k-k+1].add(c);
if ( k>1 ) _LOOK(t.target, alt, k-1, context);
if ( k>1 ) _LOOK(t.target, k-1, context);
}
}
}
public IntervalSet LOOK(NFAState s) {
System.out.println("LOOK("+s.stateNumber+")");
lookBusy.clear();
IntervalSet fset = new IntervalSet();
_LOOK(s, NFAContext.EMPTY(), fset);
return fset;
}
void _LOOK(NFAState s, NFAContext context, IntervalSet fset) {
//System.out.println("_LOOK("+s.stateNumber+", "+k+", ctx="+context);
LookaheadNFAConfig ac = new LookaheadNFAConfig(s,1,context);
if ( lookBusy.contains(ac) ) return;
lookBusy.add(ac);
if ( s instanceof RuleStopState && !context.isEmpty() ) {
_LOOK(context.returnState, context.parent, fset);
return;
}
int n = s.getNumberOfTransitions();
for (int i=0; i<n; i++) {
Transition t = s.transition(i);
if ( t instanceof RuleTransition ) {
NFAContext newContext =
new NFAContext(context, ((RuleTransition)t).followState);
_LOOK(t.target, newContext, fset);
}
else if ( t.isEpsilon() ) {
_LOOK(t.target, context, fset);
}
else {
fset.addAll( t.label() );
}
}
}

11
tool/src/org/antlr/v4/codegen/src/MatchToken.java
View File

@ -1,15 +1,22 @@
package org.antlr.v4.codegen.src;
import org.antlr.v4.analysis.LinearApproximator;
import org.antlr.v4.codegen.CodeGenerator;
import org.antlr.v4.misc.IntervalSet;
import org.antlr.v4.tool.TerminalAST;
/** */
public class MatchToken extends SrcOp {
public int ttype;
public IntervalSet[] follow;
public String name;
public String bitSetName;
public MatchToken(CodeGenerator gen, TerminalAST ast) {
this.gen = gen;
name = ast.getText();
LinearApproximator approx = new LinearApproximator(gen.g, -1);
IntervalSet follow = approx.LOOK(ast.nfaState.transition(0).target);
System.out.println("follow="+follow);
//bitSetName = gen.defineBitSet(follow);
}
}