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Java Lookahead Parser Generator. Generator produces LALR(k) parsers. Grammar
rules are entered using annotations. Rule annotation can be attached to reducer
method, which keeps rule and it's action together.
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/*
* Copyright (C) 2012 Timo Vesalainen
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see extends MethodCompiler
{
public static int MAXSTATES = 2000;
public static int MAXSTATESUSEWIDE = 500;
public static int dfaCount;
public static int byteCount;
protected DFA dfa;
protected T errorToken;
protected T eofToken;
protected TypeMirror tokenType;
protected boolean subCompiler;
protected boolean repeats;
private final Jav jav = new Jav();
public DFACompiler(DFA dfa, T errorToken, T eofToken)
{
this.dfa = dfa;
this.errorToken = errorToken;
this.eofToken = eofToken;
TypeMirror errorType = Typ.getTypeFor(errorToken.getClass());
if (Typ.isSameType(Typ.String, errorType))
{
this.tokenType = Typ.String;
}
else
{
this.tokenType = Typ.unboxedType(errorType);
}
if (!Typ.isJavaConstantType(tokenType))
{
throw new IllegalArgumentException(tokenType+" is not java constant class");
}
for (DFAState state : dfa)
{
if (
eofToken.equals(state.getToken()) ||
errorToken.equals(state.getToken())
)
{
throw new IllegalArgumentException(state.getToken()+" token is also error or eof token");
}
}
}
@Override
public void implement() throws IOException
{
if (!Typ.isSameType(tokenType, getReturnType()))
{
throw new IllegalArgumentException(tokenType+" is not expected return type "+getReturnType()+" of method");
}
if (dfa.initialSize() > MAXSTATES)
{
SubClass subClass = getSubClass();
DFADistributor dd = new DFADistributor<>(dfa, MAXSTATES);
dd.distribute();
for (DFA ddfa : dd.getDistributedDFAs())
{
String subName = jav.makeJavaIdentifier(getMethodDescription()+ddfa.name());
ExecutableElement distributedMethod = getDistributedMethod(subName);
DFACompiler sc = copy(ddfa);
sc.setSubCompiler(true);
subClass.defineMethod(sc, distributedMethod);
}
}
try
{
compile();
}
catch (NoSuchMethodException ex)
{
throw new IOException(ex);
}
}
protected ExecutableElement getDistributedMethod(String newName)
{
ExecutableElement distributedMethod = El.createUpdateableElement(executableElement);
UpdateableElement ue = (UpdateableElement) distributedMethod;
ue.setSimpleName(El.getName(newName));
return distributedMethod;
}
protected void compile() throws IOException, NoSuchMethodException
{
if (dfa.initialSize() > MAXSTATESUSEWIDE)
{
setWideIndex(true);
}
nameArgument("reader", 1);
addVariable("cc", int.class);
addVariable("accepted", tokenType);
//if (repeats)
{
addVariable("index", int.class);
}
fixAddress("start");
iconst(-1);
tstore("cc");
tconst(errorToken);
tstore("accepted");
int count = 0;
Iterator> si = dfa.iterator();
while (si.hasNext())
{
DFAState s = si.next();
compile(s, !si.hasNext());
count++;
}
fixAddress("error");
error();
fixAddress("pushback");
pushback();
fixAddress("exit");
exit();
fixAddress("eof");
eof();
dfaCount += dfa.initialSize();
byteCount += position();
}
protected abstract void error() throws IOException, NoSuchMethodException;
protected void pushback() throws IOException, NoSuchMethodException
{
}
protected abstract void exit() throws IOException, NoSuchMethodException;
protected void afterState(DFAState s) throws IOException, NoSuchMethodException
{
}
protected void compile(DFAState s, boolean isLast) throws IOException, NoSuchMethodException
{
fixAddress(s.toString());
accepting(s);
if (s.hasBoundaryMatches())
{
// boundary match is the only transition
if (s.getTransitions().size() != 1)
{
throw new IllegalArgumentException("number of boundary match transitions not 1. -> illegal usage of boundary match");
}
for (Transition tr : s.getTransitions())
{
Range range = tr.getCondition();
DFAState to = s.transit(range);
tload("reader");
iconst(range.getBoundaryMatcher());
invokevirtual(InputReader.class, "isAtBoundary", int.class);
ifeq("error");
goto_n(to.toString());
}
}
else
{
Iterator>> ti = s.getTransitions().iterator();
if (ti.hasNext())
{
Transition> first = ti.next();
if (first.getRepeat() > 1)
{
tconst(first.getRepeat());
tstore("index");
String back = s.toString()+"-repeat";
fixAddress(back);
tload("reader");
invokevirtual(InputReader.class, "read");
tstore("cc");
tload("cc");
iflt("eof");
Range range = first.getCondition();
DFAState to = s.transit(range);
compile(range, "error", !ti.hasNext());
// ok
tinc("index", -1);
tload("index");
ifne(back);
gotoNext(to);
}
else
{
tload("reader");
invokevirtual(InputReader.class, "read");
tstore("cc");
tload("cc");
iflt("eof");
if (s.getTransitionSelectivity() > 2)
{
Iterator>> tri = s.getTransitions().iterator();
while (tri.hasNext())
{
Transition tr = tri.next();
Range range = tr.getCondition();
DFAState to = s.transit(range);
String next = s.toString()+"-"+range+">"+to.toString();
compile(range, next, !tri.hasNext());
// ok
afterState(s);
gotoNext(to);
fixAddress(next);
}
}
else
{
LookupList ll = new LookupList();
for (Transition tr : s.getTransitions())
{
Range range = tr.getCondition();
if (range.getFrom() >= 0)
{
DFAState to = s.transit(range);
String target = s.toString()+"-"+range+">"+to.toString();
for (int ii=range.getFrom();ii to = s.transit(range);
String target = s.toString()+"-"+range+">"+to.toString();
fixAddress(target);
// ok
afterState(s);
gotoNext(to);
}
}
}
}
else
{
if (s.isAccepting())
{
goto_n("exit");
}
else
{
goto_n("error");
}
}
}
}
protected void gotoNext(DFAState s) throws IOException, NoSuchMethodException
{
if (s.isDistributed())
{
String subName = jav.makeJavaIdentifier(getMethodDescription()+s);
ExecutableElement distributedMethod = getDistributedMethod(subName);
tload("this");
tload("reader");
invoke(distributedMethod);
treturn();
}
else
{
goto_n(s.toString());
}
}
protected void accepting(DFAState s) throws IOException, NoSuchMethodException
{
if (s.isAccepting())
{
tconst(s.getToken());
tstore("accepted");
}
else
{
tconst(errorToken);
tstore("accepted");
}
}
protected void compile(Range range, String next, boolean isLast) throws IOException
{
if ((range.getTo() - range.getFrom()) == 1)
{
tload("cc");
iconst(range.getFrom());
if (isLast)
{
if_icmpne("error");
}
else
{
if_icmpne(next);
}
}
else
{
if (range.getFrom() >= -1)
{
tload("cc");
iconst(range.getFrom());
if (isLast)
{
if_icmplt("error");
}
else
{
if_icmplt(next);
}
}
if (range.getTo() < Integer.MAX_VALUE)
{
tload("cc");
iconst(range.getTo());
if (isLast)
{
if_icmpge("error");
}
else
{
if_icmpge(next);
}
}
}
}
private void eof() throws IOException
{
tload("accepted");
tconst(errorToken);
if_tcmpne(tokenType, "eofacc");
tconst(eofToken);
treturn();
fixAddress("eofacc");
tload("accepted");
treturn();
}
protected boolean literal(DFAState s) throws IOException
{
return false;
}
protected abstract DFACompiler copy(DFA ddfa);
public void setSubCompiler(boolean subCompiler)
{
this.subCompiler = subCompiler;
}
}
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