/**
* $Id$
*/
package scalac.transformer.matching ;
import scalac.*;
import scalac.ast.*;
import scalac.symtab.*;
import Tree.*;
import scalac.transformer.TransMatch.Matcher ;
import java.util.* ;
import Scope.SymbolIterator;
import scalac.ast.printer.TextTreePrinter ;
import scalac.util.Name ;
import scalac.util.Names ;
import ch.epfl.lamp.util.Position;
public class RightTracerInScala extends TracerInScala {
//Scope scp;
//Symbol vars[];
Vector seqVars;
Vector allVars;
Matcher _m;
// Symbol funSym;
Symbol elemSym;
Symbol targetSym;
HashMap helpMap2 ;
Vector helpVarDefs;
/** translate right tracer to code
* @param dfa determinized left tracer
* @param left nondeterm. left tracer
* @param cf ...
* @param pat ?
* @param elementType ...
*/
public RightTracerInScala( DetWordAutom dfa,
NondetWordAutom left,
Matcher m,
CodeFactory cf,
Tree pat,
Type elementType ) {
super( dfa, elementType, m.owner, cf );
this._m = m;
Vector seqVars = new Vector();
for( int j = 0; j < left.nstates; j++ ) {
if( left.qbinders[ j ] != null )
for( Iterator it = left.qbinders[ j ].iterator();
it.hasNext() ; ) {
Symbol varSym = (Symbol) it.next();
if( !seqVars.contains( varSym ) )
seqVars.add( varSym );
}
}
this.seqVars = seqVars;
this.allVars = CollectVariableTraverser.collectVars( pat );
helpMap2 = new HashMap();
helpVarDefs = new Vector();
for( Iterator it = seqVars.iterator(); it.hasNext(); ) {
makeHelpVar( (Symbol) it.next() );
}
for( Iterator it = allVars.iterator(); it.hasNext(); ) {
Symbol varSym = (Symbol) it.next();
if( !seqVars.contains( varSym )) {
makeHelpVar( varSym, true );
}
}
initializeSyms();
}
void makeHelpVar( Symbol realVar ) {
makeHelpVar( realVar, false );
}
/** makes a helpvar and puts mapping into helpMap, ValDef into helpVarDefs
*/
void makeHelpVar( Symbol realVar, boolean keepType ) {
Symbol helpVar = new TermSymbol( pos,
cf.fresh.newName( realVar.name
.toString() ),
owner,
0);
//System.out.println("making helpvar : "+realVar+" -> "+helpVar);
if( keepType )
helpVar.setType( realVar.type() );
else
helpVar.setType( defs.LIST_TYPE(elementType) );
helpMap.put( realVar, helpVar );
Tree rhs;
if( keepType )
rhs = gen.mkDefaultValue( cf.pos, realVar.type() );
else
rhs = gen.Nil( cf.pos );
helpVar.flags |= Modifiers.MUTABLE;
Tree varDef = gen.ValDef( helpVar, rhs );
//((ValDef) varDef).kind = Kinds.VAR;
helpVarDefs.add( varDef );
}
Tree prependToHelpVar( Symbol realVar, Tree elem ) {
Tree hv = refHelpVar( realVar );
return gen.Assign( hv, gen.Cons( cf.pos, elem.type(), elem, hv ));
/*
return cf.Block(pos,
new Tree [] {
cf.debugPrintRuntime( "ASSIGN" ),
gen.Assign( hv, cf.newSeqCons( elem, hv ))
}, defs.UNIT_TYPE());
*/
}
protected void initializeSyms() {
this.funSym = newFunSym( "binder" );
this.iterSym = new TermSymbol( pos,
cf.fresh.newName("iter"),
funSym,
0)
.setType( cf.SeqTraceType( elementType ));
this.stateSym = new TermSymbol( pos,
cf.fresh.newName("q"),
funSym,
0 )
.setType( defs.INT_TYPE() ) ;
this.elemSym = new TermSymbol( pos,
cf.fresh.newName("elem"),
funSym,
0)
.setType( elementType ) ;
this.targetSym = new TermSymbol( pos,
cf.fresh.newName("trgt"),
funSym,
0)
.setType( defs.INT_TYPE() ) ;
funSym.setType( new Type.MethodType( new Symbol[] {
iterSym, stateSym }, defs.UNIT_TYPE() ));
}
// same as in LeftTracer
Tree code_fail() {
return cf.ThrowMatchError( _m.pos, defs.UNIT_TYPE() );
}
public Tree code_body() {
Tree body = code_fail(); // never reached at runtime.
// state [ nstates-1 ] is the dead state, so we skip it
//`if( state == q ) <code_state> else {...}'
for( int i = dfa.nstates-1; i >= 0; i-- ) {
body = code_state( i, body );
}
Tree t3 = gen.If( cf.isEmpty( _iter() ),
run_finished( 0 ),
gen.mkBlock( new Tree[] {
gen.ValDef( targetSym,
cf.SeqTrace_headState( gen.Ident( pos, iterSym))),
gen.ValDef( elemSym,
cf.SeqTrace_headElem( gen.Ident( pos, iterSym))),
body }));
/*
t3 = gen.mkBlock( new Tree[] {
cf.debugPrintRuntime("enter binderFun"),
cf.debugPrintRuntime(" state:"),
cf.debugPrintRuntime( gen.Ident( pos, stateSym )),
cf.debugPrintRuntime(" iter:"),
cf.debugPrintRuntime(_iter()),
cf.debugPrintNewlineRuntime(""),
t3 });
*/
//System.out.println("enter RightTracerInScala:code_body()");// DEBUG
//System.out.println("dfa.nstates"+dfa.nstates);// DEBUG
return t3;
}
/** this one is special, we check the first element of the trace
* and choose the next state depending only on the state part
*/
Tree code_state0( Tree elseBody ) { // careful, map Int to Int
HashMap hmap = (HashMap) dfa.deltaq( 0 ); // all the initial states
Tree stateBody = code_fail(); // never happens
for( Iterator it = hmap.keySet().iterator(); it.hasNext(); ) {
Integer targetL = (Integer) it.next();
Integer targetR = (Integer) hmap.get( targetL );
stateBody = gen.If( cf.Equals( gen.Ident( pos, targetSym ),
gen.mkIntLit( cf.pos, targetL )),
callFun( new Tree[] {
cf.SeqTrace_tail( _iter() ),
gen.mkIntLit( cf.pos, targetR ) }),
stateBody );
}
return gen.If( cf.Equals( _state(), gen.mkIntLit( cf.pos, 0 )),
stateBody ,
elseBody );
}
Tree code_state( int i, Tree elseBody ) {
if( i == 0 )
return code_state0( elseBody );
int finalSwRes;
Tree stateBody ; // action(delta) for one particular label/test
// default action (fail if there is none)
stateBody = code_delta( i, Label.DefaultLabel);
if( stateBody == null )
stateBody = code_fail();
// transitions of state i
HashMap trans = ((HashMap[])dfa.deltaq)[ i ];
for( Iterator labs = dfa.labels.iterator(); labs.hasNext() ; ) {
Object label = labs.next();
Integer next = (Integer) trans.get( label );
Tree action = code_delta( i, (Label) label );
if( action != null ) {
stateBody = gen.If( _cur_eq( _iter(), (Label) label ),
action,
stateBody);
}
}
return gen.If( cf.Equals( _state(), gen.mkIntLit( cf.pos, i )),
stateBody ,
elseBody );
}
/** returns a Tree whose type is boolean.
* now we care about free vars
*/
Tree handleBody1( HashMap helpMap3 ) {
//System.out.println("Rtis.handleBody ... helpMap = " + helpMap );
// todo: change helpMap s.t. symbols are not reused.
Tree res[] = new Tree[ helpMap3.keySet().size() + 1 ];
int j = 0;
for( Iterator it = helpMap3.keySet().iterator(); it.hasNext(); ) {
Symbol vsym = (Symbol) it.next();
Symbol hv = (Symbol) helpMap3.get( vsym );
hv.setType( defs.LIST_TYPE( elementType ) ) ;
Tree refv = gen.Ident(Position.FIRSTPOS, vsym);
Tree refhv = gen.Ident(Position.FIRSTPOS, hv);
res[ j++ ] = gen.Assign( refhv, refv );
}
res[ j ] = gen.mkBooleanLit( Position.FIRSTPOS, true ); // just `true'
return gen.mkBlock(res);
}
// calling the AlgebraicMatcher here
Tree _cur_match( Tree pat ) {
//System.out.println("RTiS._cur_match("+pat.toString()+")");
//System.out.println("calling algebraic matcher on type:"+pat.type);
Matcher m = new Matcher( funSym,//this.funSym,
currentElem(),
defs.BOOLEAN_TYPE() );
// there could be variables in regular expressions under Sequence node,
// export those later
Vector varsToExport = NoSeqVariableTraverser.varsNoSeq( pat );
HashMap freshenMap = new HashMap();
HashMap helpMap3 = new HashMap();
// "freshening": never use the same symbol more than once
// (in later invocations of _cur_match)
for( Iterator it = varsToExport.iterator(); it.hasNext(); ) {
Symbol key = (Symbol) it.next();
this.helpMap2.put( key, helpMap.get( key ));
// "freshening"
Symbol newSym = key.cloneSymbol();
newSym.name = key.name.append( Name.fromString("gu234") ); // is fresh now :-)
freshenMap.put( key, newSym );
helpMap3.put( newSym, helpMap.get( key ));
}
//System.out.println("RightTracerInScala::freshenMap :"+freshenMap);
//System.out.println("RightTracerInScala:: -pat :"+pat.toString());
//System.out.println("RightTracerInScala::varsToExport :"+varsToExport);
// "freshening"
TreeCloner st = new TreeCloner(cf.unit.global, freshenMap, Type.IdMap );
pat = st.transform( pat );
//System.out.println("RightTracerInScala:: -pat( after subst ) :"+pat);
// val match { case <pat> => { <do binding>; true }
// case _ => false
am.construct( m, new CaseDef[] {
cf.gen.CaseDef( pat, // if tree val matches pat -> update vars, return true
handleBody1( helpMap3 )/* "freshening */),
cf.gen.CaseDef( cf.gen.Ident( pat.pos, defs.PATTERN_WILDCARD ),
gen.mkBooleanLit( pat.pos, false )) }, // else return false
true // do binding please
);
return am.toTree();
}
/** returns translation of transition with label from i.
* returns null if there is no such transition(no translation needed)
*/
Tree code_delta( int i, Label label ) {
HashMap hmap = (HashMap) dfa.deltaq( i );
Integer ntarget = (Integer) hmap.get( label );
Tree algMatchTree = null;
if( ntarget == null )
return null;
//System.out.println("delta("+i+","+label+")" );
Label theLab = null;
switch(label) {
case Label.Pair( Integer state, Label lab2 ):
//assert ntarget == state;
theLab = lab2;
switch( lab2 ) {
case TreeLabel( Tree pat ):
algMatchTree = _cur_match( pat );
break;
}
break;
case DefaultLabel:
throw new ApplicationError(); // should not happen
}
assert dfa.qbinders != null : "qbinders ?";
Vector vars = dfa.qbinders[ i ];
if( vars == null ) vars = new Vector(); // TODO: make this more consistent
assert vars != null;
//System.out.println("delta: theLab: " + theLab + " vars in current ="+ vars );
if( ntarget == null )
return code_fail();
Tree stms[] = new Tree[ vars.size()
+ ((algMatchTree != null )? 1 : 0 )
+ 1 ];
int j = 0;
for( Iterator it = vars.iterator(); it.hasNext(); ) {
Symbol var = (Symbol) it.next();
Tree rhs = gen.Ident( pos, elemSym );
stms[ j++ ] = prependToHelpVar( var , rhs);
}
if( algMatchTree != null )
stms[ j++ ] = algMatchTree ;
stms[ j ] = callFun( new Tree[] { cf.SeqTrace_tail( _iter() ),
gen.mkIntLit( cf.pos, ntarget ) } );
return gen.mkBlock( pos, stms );
}
/* returns statements that do the work of the right-transducer
*/
Tree[] getStms( Tree trace ) {
//System.out.println( "!!getStms.helpVarDefs: "+helpVarDefs);
Vector v = new Vector();
for( Iterator it = helpVarDefs.iterator(); it.hasNext(); )
v.add( (Tree) it.next() );
v.add( gen.DefDef( this.funSym, code_body() ) );
v.add( callFun( new Tree[] { trace, gen.mkIntLit( cf.pos, 0 ) } ) );
/*
for(Iterator it = helpMap.keySet().iterator(); it.hasNext(); ) {
// DEBUG
Symbol var = (Symbol)it.next();
v.add( cf.debugPrintRuntime( var.name.toString() ));
v.add( cf.debugPrintRuntime( refHelpVar( var )) );
}
*/
for( Iterator it = seqVars.iterator(); it.hasNext(); ) {
v.add( bindVar( (Symbol) it.next() ) );
}
Tree result[] = new Tree[ v.size() ];
int j = 0;
for( Iterator it = v.iterator(); it.hasNext(); ) {
result[ j++ ] = (Tree) it.next();
}
// helpvarSEQ via _m.varMap
return result;
}
/** return the accumulator. (same as in LeftTracerInScala)
* todo: move tree generation of Unit somewhere else
*/
Tree run_finished( int state ) {
return gen.Block(Position.FIRSTPOS, Tree.EMPTY_ARRAY);
}
Tree current() {
return gen.Ident( pos, targetSym );
}
Tree currentElem() {
return gen.Ident( pos, elemSym );
}
Tree _cur_eq( Tree iter, Label label ) {
//System.out.println("_cur_eq, thelab: "+label);
switch( label ) {
case Pair( Integer target, Label theLab ):
return cf.Equals( gen.mkIntLit( cf.pos, target ),
current() );
}
throw new ApplicationError("expected Pair label");
}
}