public static NfaPair NewNLPair(Spec spec)
{
NfaPair nfaPair = Alloc.NewNfaPair();
nfaPair.end = Alloc.NewNfa(spec);
nfaPair.start = Alloc.NewNfa(spec);
Nfa start = nfaPair.start;
start.Next = Alloc.NewNfa(spec);
Nfa next = start.Next;
next.Edge = '';
next.SetCharSet(new CharSet());
next.GetCharSet().add(10);
next.Next = nfaPair.end;
start.Sibling = Alloc.NewNfa(spec);
Nfa sibling = start.Sibling;
sibling.Edge = '\r';
sibling.Next = Alloc.NewNfa(spec);
Nfa next2 = sibling.Next;
next2.Next = null;
next2.Sibling = Alloc.NewNfa(spec);
next2.Sibling.Edge = '\n';
next2.Sibling.Next = nfaPair.end;
return(nfaPair);
}
/*
* Function: cat_expr
* Description: Recursive descent regular expression parser.
*/
private static void cat_expr(NfaPair pair)
{
NfaPair e2_pair;
#if DESCENT_DEBUG
Utility.enter("cat_expr", spec.lexeme, spec.current_token);
#endif
#if DEBUG
Utility.assert(null != pair);
#endif
e2_pair = Alloc.NewNfaPair();
if (first_in_cat(spec.current_token))
{
factor(pair);
}
while (first_in_cat(spec.current_token))
{
factor(e2_pair);
/* Destroy */
pair.end.mimic(e2_pair.start);
discardNfa(e2_pair.start);
pair.end = e2_pair.end;
}
#if DESCENT_DEBUG
Utility.leave("cat_expr", spec.lexeme, spec.current_token);
#endif
}
private static void cat_expr(NfaPair pair)
{
NfaPair nfaPair = Alloc.NewNfaPair();
if (MakeNfa.first_in_cat(MakeNfa.spec.current_token))
{
MakeNfa.factor(pair);
}
while (MakeNfa.first_in_cat(MakeNfa.spec.current_token))
{
MakeNfa.factor(nfaPair);
pair.end.mimic(nfaPair.start);
MakeNfa.discardNfa(nfaPair.start);
pair.end = nfaPair.end;
}
}
private static Nfa rule()
{
int num = 0;
NfaPair nfaPair = Alloc.NewNfaPair();
Nfa nfa;
Nfa end;
if (MakeNfa.spec.current_token == Tokens.AT_BOL)
{
num |= 1;
MakeNfa.gen.Advance();
MakeNfa.expr(nfaPair);
nfa = Alloc.NewNfa(MakeNfa.spec);
nfa.Edge = MakeNfa.spec.BOL;
nfa.Next = nfaPair.start;
end = nfaPair.end;
}
else
{
MakeNfa.expr(nfaPair);
nfa = nfaPair.start;
end = nfaPair.end;
}
if (Tokens.AT_EOL == MakeNfa.spec.current_token)
{
MakeNfa.gen.Advance();
NfaPair nfaPair2 = Alloc.NewNLPair(MakeNfa.spec);
end.Next = Alloc.NewNfa(MakeNfa.spec);
Nfa next = end.Next;
next.Next = nfaPair2.start;
next.Sibling = Alloc.NewNfa(MakeNfa.spec);
next.Sibling.Edge = MakeNfa.spec.EOF;
next.Sibling.Next = nfaPair2.end;
end = nfaPair2.end;
num |= 2;
}
if (end == null)
{
Error.ParseError(Errors.ZERO, MakeNfa.gen.InputFilePath, MakeNfa.input.line_number);
}
end.SetAccept(MakeNfa.gen.packAccept());
end.SetAnchor(num);
return(nfa);
}
private static void expr(NfaPair pair)
{
NfaPair nfaPair = Alloc.NewNfaPair();
MakeNfa.cat_expr(pair);
while (Tokens.OR == MakeNfa.spec.current_token)
{
MakeNfa.gen.Advance();
MakeNfa.cat_expr(nfaPair);
Nfa nfa = Alloc.NewNfa(MakeNfa.spec);
nfa.Sibling = nfaPair.start;
nfa.Next = pair.start;
pair.start = nfa;
nfa = Alloc.NewNfa(MakeNfa.spec);
pair.end.Next = nfa;
nfaPair.end.Next = nfa;
pair.end = nfa;
}
}
/*
* Function: expr
* Description: Recursive descent regular expression parser.
*/
private static void expr(NfaPair pair)
{
NfaPair e2_pair;
Nfa p;
#if DESCENT_DEBUG
Utility.enter("expr", spec.lexeme, spec.current_token);
#endif
#if DEBUG
Utility.assert(null != pair);
#endif
e2_pair = Alloc.NewNfaPair();
cat_expr(pair);
while (Gen.OR == spec.current_token)
{
gen.Advance();
cat_expr(e2_pair);
p = Alloc.NewNfa(spec);
p.SetSib(e2_pair.start);
p.SetNext(pair.start);
pair.start = p;
p = Alloc.NewNfa(spec);
pair.end.SetNext(p);
e2_pair.end.SetNext(p);
pair.end = p;
}
#if DESCENT_DEBUG
Utility.leave("expr", spec.lexeme, spec.current_token);
#endif
}
/*
* Function: rule
* Description: Recursive descent regular expression parser.
*/
private static Nfa rule()
{
NfaPair pair;
Nfa start = null;
Nfa end = null;
int anchor = Spec.NONE;
#if DESCENT_DEBUG
Utility.enter("rule", spec.lexeme, spec.current_token);
#endif
pair = Alloc.NewNfaPair();
if (Gen.AT_BOL == spec.current_token)
{
anchor = anchor | Spec.START;
gen.Advance();
expr(pair);
start = Alloc.NewNfa(spec);
start.SetEdge(spec.BOL);
start.SetNext(pair.start);
end = pair.end;
}
else
{
expr(pair);
start = pair.start;
end = pair.end;
}
if (Gen.AT_EOL == spec.current_token)
{
gen.Advance();
NfaPair nlpair = Alloc.NewNLPair(spec);
end.SetNext(Alloc.NewNfa(spec));
Nfa enext = end.GetNext();
enext.SetNext(nlpair.start);
enext.SetSib(Alloc.NewNfa(spec));
enext.GetSib().SetEdge(spec.EOF);
enext.GetSib().SetNext(nlpair.end);
end = nlpair.end;
anchor = anchor | Spec.END;
}
/* check for null rules */
if (end == null)
{
Error.parse_error(Error.E_ZERO, input.line_number);
}
/* Handle end of regular expression */
end.SetAccept(gen.packAccept());
end.SetAnchor(anchor);
#if DESCENT_DEBUG
Utility.leave("rule", spec.lexeme, spec.current_token);
#endif
return(start);
}