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yap-6.3/C/readutil.c

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/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: readutil.c *
* Last rev: 2/8/06 *
* mods: *
* comments: readutil library support *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif
#include "Yap.h"
#include "Yatom.h"
#include "YapHeap.h"
#include "yapio.h"
#include "iopreds.h"
static Int
rl_to_codes(Term TEnd, int do_as_binary, int arity)
{
int sno = Yap_CheckStream (ARG1, Input_Stream_f, "read_line_to_codes/2");
Int status;
UInt max_inp, buf_sz, sz;
char *buf;
int binary_stream;
if (sno < 0)
return FALSE;
status = Stream[sno].status;
binary_stream = Stream[sno].status & Binary_Stream_f;
if (status & Eof_Stream_f) {
UNLOCK(Stream[sno].streamlock);
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return Yap_unify_constant(ARG2, MkAtomTerm (AtomEof));
}
max_inp = (ASP-H)/2-1024;
buf = (char *)TR;
buf_sz = (char *)Yap_TrailTop-buf;
while (TRUE) {
if ( buf_sz > max_inp ) {
buf_sz = max_inp;
}
if (do_as_binary && !binary_stream)
Stream[sno].status |= Binary_Stream_f;
sz = Stream[sno].stream_gets(sno, buf_sz, buf);
if (do_as_binary && !binary_stream)
Stream[sno].status &= ~Binary_Stream_f;
if (sz == -1 || sz == 0) {
if (Stream[sno].status & Eof_Stream_f) {
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UNLOCK(Stream[sno].streamlock);
return Yap_unify_constant(ARG2, MkAtomTerm (AtomEof));
}
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UNLOCK(Stream[sno].streamlock);
return FALSE;
}
if (Stream[sno].status & Eof_Stream_f || buf[sz-1] == 10) {
/* we're done */
Term end;
if (!(do_as_binary || Stream[sno].status & Eof_Stream_f)) {
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UNLOCK(Stream[sno].streamlock);
/* handle CR before NL */
if (sz-2 >= 0 && buf[sz-2] == 13)
buf[sz-2] = '\0';
else
buf[sz-1] = '\0';
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} else {
UNLOCK(Stream[sno].streamlock);
}
if (arity == 2)
end = TermNil;
else
end = Deref(XREGS[arity]);
return Yap_unify(ARG2, Yap_StringToDiffList((char *)TR, end)) ;
}
buf += (buf_sz-1);
max_inp -= (buf_sz-1);
if (max_inp <= 0) {
UNLOCK(Stream[sno].streamlock);
Yap_Error(OUT_OF_STACK_ERROR, ARG1, "read_line_to_codes/%d", arity);
return FALSE;
}
}
}
static Int
p_rl_to_codes(void)
{
return rl_to_codes(TermNil, FALSE, 2);
}
static Int
p_rl_to_codes2(void)
{
return rl_to_codes(TermNil, TRUE, 3);
}
static Int
p_stream_to_codes(void)
{
int sno = Yap_CheckStream (ARG1, Input_Stream_f, "read_line_to_codes/2");
CELL *HBASE = H;
CELL *h0 = &ARG4;
if (sno < 0)
return FALSE;
while (!(Stream[sno].status & Eof_Stream_f)) {
/* skip errors */
Int ch = Stream[sno].stream_getc(sno);
Term t;
if (ch == EOFCHAR)
break;
t = MkIntegerTerm(ch);
h0[0] = AbsPair(H);
*H = t;
H+=2;
h0 = H-1;
if (H >= ASP-1024) {
RESET_VARIABLE(h0);
ARG4 = AbsPair(HBASE);
ARG5 = (CELL)h0;
if (!Yap_gcl((ASP-HBASE)*sizeof(CELL), 5, ENV, gc_P(P,CP))) {
Yap_Error(OUT_OF_STACK_ERROR, ARG1, "read_stream_to_codes/3");
return FALSE;
}
/* build a legal term again */
h0 = (CELL *)ARG5;
HBASE = RepPair(ARG4);
}
}
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UNLOCK(Stream[sno].streamlock);
if (H == HBASE)
return Yap_unify(ARG2,ARG3);
RESET_VARIABLE(H-1);
Yap_unify(H[-1],ARG3);
return Yap_unify(AbsPair(HBASE),ARG2);
}
static Int
p_stream_to_terms(void)
{
int sno = Yap_CheckStream (ARG1, Input_Stream_f, "read_line_to_codes/2");
Term t = Deref(ARG3), tpos = TermNil;
if (sno < 0)
return FALSE;
while (!(Stream[sno].status & Eof_Stream_f)) {
/* skip errors */
TokEntry *tokstart = Yap_tokptr = Yap_toktide = Yap_tokenizer(sno, &tpos);
if (!Yap_ErrorMessage)
{
Term th = Yap_Parse();
if (H >= ASP-1024) {
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UNLOCK(Stream[sno].streamlock);
Yap_Error(OUT_OF_STACK_ERROR, ARG1, "read_stream_to_terms/3");
return FALSE;
}
if (!th || Yap_ErrorMessage)
break;
if (th == MkAtomTerm (AtomEof)) {
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UNLOCK(Stream[sno].streamlock);
Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
return Yap_unify(t,ARG2);
} else {
t = MkPairTerm(th,t);
}
}
Yap_clean_tokenizer(tokstart, Yap_VarTable, Yap_AnonVarTable);
}
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UNLOCK(Stream[sno].streamlock);
return Yap_unify(t,ARG2);
}
void
Yap_InitReadUtil(void)
{
Term cm = CurrentModule;
CurrentModule = READUTIL_MODULE;
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Yap_InitCPred("read_line_to_codes", 2, p_rl_to_codes, SyncPredFlag);
Yap_InitCPred("read_line_to_codes", 3, p_rl_to_codes2, SyncPredFlag);
Yap_InitCPred("read_stream_to_codes", 3, p_stream_to_codes, SyncPredFlag);
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Yap_InitCPred("read_stream_to_terms", 3, p_stream_to_terms, SyncPredFlag);
CurrentModule = cm;
}