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yap-6.3/os/readterm.c

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read_term/3
2015-06-18 01:20:05 +01:00
/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: iopreds.c *
* Last rev: 5/2/88 *
* mods: *
* comments: Input/Output C implemented predicates *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif
/*
* This file includes the definition of a miscellania of standard predicates
* for yap refering to: Files and GLOBAL_Streams, Simple Input/Output,
*
*/
#include "Yap.h"
#include "Yatom.h"
#include "YapHeap.h"
#include "yapio.h"
#include "eval.h"
#include "YapText.h"
#include <stdlib.h>
#if HAVE_STDARG_H
#include <stdarg.h>
#endif
#if HAVE_CTYPE_H
#include <ctype.h>
#endif
#if HAVE_WCTYPE_H
#include <wctype.h>
#endif
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_SELECT_H && !_MSC_VER && !defined(__MINGW32__)
#include <sys/select.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#endif
#if HAVE_SIGNAL_H
#include <signal.h>
#endif
#if HAVE_FCNTL_H
/* for O_BINARY and O_TEXT in WIN32 */
#include <fcntl.h>
#endif
#ifdef _WIN32
#if HAVE_IO_H
/* Windows */
#include <io.h>
#endif
#endif
#if !HAVE_STRNCAT
#define strncat(X,Y,Z) strcat(X,Y)
#endif
#if !HAVE_STRNCPY
#define strncpy(X,Y,Z) strcpy(X,Y)
#endif
#if _MSC_VER || defined(__MINGW32__)
#if HAVE_SOCKET
#include <winsock2.h>
#endif
#include <windows.h>
#ifndef S_ISDIR
#define S_ISDIR(x) (((x)&_S_IFDIR)==_S_IFDIR)
#endif
#endif
#include "iopreds.h"
#if _MSC_VER || defined(__MINGW32__)
#define SYSTEM_STAT _stat
#else
#define SYSTEM_STAT stat
#endif
static void
clean_vars(VarEntry *p)
{
if (p == NULL) return;
p->VarAdr = TermNil;
clean_vars(p->VarLeft);
clean_vars(p->VarRight);
}
#undef PAR
#ifdef O_QUASIQUOTATIONS
/** '$qq_open'(+QQRange, -Stream) is det.
Opens a quasi-quoted memory range.
@arg QQRange is a term '$quasi_quotation'(ReadData, Start, Length)
@arg Stream is a UTF-8 encoded string, whose position indication
reflects the location in the real file.
*/
static Int
qq_open( USES_REGS1)
{ PRED_LD
Term t = Deref(ARG1);
if ( !IsVarTerm(t) &&
IsApplTerm(t) &&
FunctorOfTerm(t) = FunctorDQuasiQuotation)
{ void *ptr;
char * start;
size_t l int s;
Teerm t0, t1, t2;
if ( IsPointerTerm((t0 = ArgOfTerm(1, t))) &&
IsPointerTerm((t1 = ArgOfTerm(2, t))) &&
IsIntegerTerm((t2 = ArgOfTerm(3, t))))
{
ptr = PointerOfTerm(t0);
start = PointerOfTerm(t1);
len = IntegerOfTerm(t2);
if ((s = Yap_open_buf_read_stream( start, len, ENC_UTF8, MEM_BUF_USER)) < 0)
return false;
return Yap_unify(ARG2, Yap_MkStream(s));
} else {
Yap_Error(TYPE_ERROR_READ_CONTEXT, t);
}
return FALSE;
}
}
static int
parse_quasi_quotations(ReadData _PL_rd ARG_LD)
{ if ( _PL_rd->qq_tail )
{ term_t av;
int rc;
if ( !PL_unify_nil(_PL_rd->qq_tail) )
return FALSE;
if ( !_PL_rd->quasi_quotations )
{ if ( (av = PL_new_term_refs(2)) &&
PL_put_term(av+0, _PL_rd->qq) &&
#if __YAP_PROLOG__
PL_put_atom(av+1, YAP_SWIAtomFromAtom(_PL_rd->module->AtomOfME)) &&
#else
PL_put_atom(av+1, _PL_rd->module->name) &&
#endif
PL_cons_functor_v(av, FUNCTOR_dparse_quasi_quotations2, av) )
{ term_t ex;
rc = callProlog(MODULE_system, av+0, PL_Q_CATCH_EXCEPTION, &ex);
if ( rc )
return TRUE;
_PL_rd->exception = ex;
_PL_rd->has_exception = TRUE;
}
return FALSE;
} else
return TRUE;
} else if ( _PL_rd->quasi_quotations ) /* user option, but no quotes */
{ return PL_unify_nil(_PL_rd->quasi_quotations);
} else
return TRUE;
}
#endif /*O_QUASIQUOTATIONS*/
#define READ_DEFS() \
PAR( "comments", filler, READ_COMMENTS), \
PAR( "module", isatom, READ_MODULE ), \
PAR( "priority", nat, READ_PRIORITY ), \
PAR( "quasi_quotations", filler, READ_QUASI_QUOTATIONS ), \
PAR( "term_position", filler, READ_TERM_POSITION ), \
PAR( "syntax_errors", isatom, READ_SYNTAX_ERRORS ), \
PAR( "singletons", filler, READ_SINGLETONS ), \
PAR( "variables", filler, READ_VARIABLES ), \
PAR( "variable_names", filler, READ_VARIABLE_NAMES ), \
PAR( "character_escapes", boolean, READ_CHARACTER_ESCAPES ), \
PAR( "backquoted_string", isatom, READ_BACKQUOTED_STRING ), \
PAR( "cycles", ok, READ_CYCLES ), \
PAR( NULL, ok, READ_END )
#define PAR(x,y,z) z
typedef enum open_enum_choices
{
READ_DEFS()
} open_choices_t;
#undef PAR
#define PAR(x,y,z) { x , y, z }
static const param_t read_defs[] =
{
READ_DEFS()
};
#undef PAR
Term
Yap_syntax_error (TokEntry * tokptr, int sno)
{
CACHE_REGS
Term info;
int count = 0;
Term out, start, err = 0, end;
Term tf[7];
Term *error = tf+3;
CELL *Hi = HR;
start = tokptr->TokPos;
clean_vars(LOCAL_VarTable);
clean_vars(LOCAL_AnonVarTable);
out = AbsPair( HR );
while (1) {
Term ts[2];
if (HR > ASP-1024) {
tf[3] = TermNil;
err = 0;
end = 0;
/* for some reason moving this earlier confuses gcc on solaris */
HR = Hi;
break;
}
if (tokptr == LOCAL_toktide) {
err = tokptr->TokPos;
out = count;
}
info = tokptr->TokInfo;
switch (tokptr->Tok) {
case Name_tok:
{
Term t0[1];
t0[0] = MkAtomTerm((Atom)info);
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomAtom,1),1,t0);
}
break;
case Number_tok:
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomNumber,1),1,&(tokptr->TokInfo));
break;
case Var_tok:
{
Term t[3];
VarEntry *varinfo = (VarEntry *)info;
t[0] = MkIntTerm(0);
t[1] = Yap_CharsToListOfCodes(varinfo->VarRep PASS_REGS);
if (varinfo->VarAdr == TermNil) {
t[2] = varinfo->VarAdr = MkVarTerm();
} else {
t[2] = varinfo->VarAdr;
}
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomGVar,3),3,t);
}
break;
case StringTerm_tok:
{
const char *s0 =(char *)info;
ts[0] = MkStringTerm( s0 );
}
break;
case String_tok:
{
Term t0 = Yap_CharsToListOfCodes((char *)info PASS_REGS);
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomString,1),1,&t0);
}
break;
case WString_tok:
{
Term t0 = Yap_WCharsToListOfCodes((wchar_t *)info PASS_REGS);
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomString,1),1,&t0);
}
break;
case Error_tok:
case eot_tok:
break;
case Ponctuation_tok:
{
char s[2];
s[1] = '\0';
if (Ord (info) == 'l') {
s[0] = '(';
} else {
s[0] = (char)info;
}
ts[0] = MkAtomTerm(Yap_LookupAtom(s));
}
}
if (tokptr->Tok == Ord (eot_tok)) {
*error = TermNil;
end = tokptr->TokPos;
break;
} else if (tokptr->Tok != Ord (Error_tok)) {
ts[1] = MkIntegerTerm(tokptr->TokPos);
*error =
MkPairTerm(Yap_MkApplTerm(FunctorMinus,2,ts),TermNil);
error = RepPair(*error)+1;
count++;
}
tokptr = tokptr->TokNext;
}
tf[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomRead,1),1,&out);
{
Term t[3];
t[0] = MkIntegerTerm(start);
t[1] = MkIntegerTerm(err);
t[2] = MkIntegerTerm(end);
tf[1] = Yap_MkApplTerm(Yap_MkFunctor(AtomBetween,3),3,t);
}
tf[2] = MkAtomTerm(AtomHERE);
tf[4] = MkIntegerTerm(out);
tf[5] = MkIntegerTerm(err);
tf[6] = StreamName(sno);
return(Yap_MkApplTerm(FunctorSyntaxError,7,tf));
}
typedef struct fenv {
Term qq, tp, sp, np, vp, ce;
} FEnv;
typedef struct renv {
Term cm, bq;
bool ce, sw;
UInt cpos;
#if HAVE_FGETPOS
fpos_t rpos;
#endif
int ungetc_oldc;
int had_ungetc;
bool seekable;
} REnv;
static bool setReadEnv( xarg *args, FEnv *fe, struct renv *old_renv, int inp_stream)
{
CACHE_REGS
old_renv->cm = CurrentModule;
old_renv->bq = getBackQuotesFlag();
old_renv->sw = trueLocalPrologFlag( SINGLE_VAR_WARNINGS_FLAG );
if (args[READ_MODULE].used) {
CurrentModule = args[READ_MODULE].tvalue;
}
if (args[READ_BACKQUOTED_STRING].used) {
if (!setBackQuotesFlag(args[READ_BACKQUOTED_STRING].tvalue))
return false;
}
if (args[READ_QUASI_QUOTATIONS].used) {
fe->qq = args[READ_QUASI_QUOTATIONS].tvalue;
} else {
fe->qq = 0;
}
if (args[READ_TERM_POSITION].used) {
fe->tp = args[READ_TERM_POSITION].tvalue;
} else {
fe->tp = 0;
}
if (args[READ_SINGLETONS].used) {
fe->sp = args[READ_SINGLETONS].tvalue;
} else {
fe->sp = 0;
}
if (args[READ_SYNTAX_ERRORS].used) {
fe->sp = args[READ_SYNTAX_ERRORS].tvalue;
} else {
fe->sp = 0;
}
if (args[READ_VARIABLES].used) {
fe->vp = args[READ_VARIABLES].tvalue;
} else {
fe->vp = 0;
}
if (args[READ_VARIABLE_NAMES].used) {
fe->np = args[READ_VARIABLE_NAMES].tvalue;
} else {
fe->np = 0;
}
if (args[READ_CHARACTER_ESCAPES].used || Yap_CharacterEscapes( CurrentModule )) {
fe->ce = true;
} else {
fe->ce = false;
}
old_renv->seekable = (GLOBAL_Stream[inp_stream].status & Seekable_Stream_f) != 0;
if (old_renv->seekable) {
if (GLOBAL_Stream[inp_stream].stream_getc == PlUnGetc) {
old_renv->had_ungetc = TRUE;
old_renv->ungetc_oldc = GLOBAL_Stream[inp_stream].och;
}
#if HAVE_FGETPOS
fgetpos(GLOBAL_Stream[inp_stream].file, &old_renv->rpos);
#else
old_renv->cpos = GLOBAL_Stream[inp_stream].charcount;
#endif
}
return true;
}
typedef enum {
SCANNER_FAILED,
PARSER_FAILED,
PARSED_WELL
} op_result;
// true if it should loop
static bool
resetReadEnv( struct renv *old_renv, int inp_stream, int why, TokEntry *tokstart, CELL * old_H, tr_fr_ptr old_TR, int nargs)
{
CACHE_REGS
CurrentModule = old_renv->cm;
setBackQuotesFlag( old_renv->bq );
setBooleanLocalPrologFlag( SINGLE_VAR_WARNINGS_FLAG , old_renv->sw );
if (why == SCANNER_FAILED) {
// fix the problem
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
if (LOCAL_Error_TYPE == OUT_OF_TRAIL_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_growtrail (sizeof(CELL) * K16, FALSE)) {
return false;
}
} else if (LOCAL_Error_TYPE == OUT_OF_AUXSPACE_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_ExpandPreAllocCodeSpace(0, NULL, TRUE)) {
return false;
}
} else if (LOCAL_Error_TYPE == OUT_OF_HEAP_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_growheap(FALSE, 0, NULL)) {
return false;
}
} else if (LOCAL_Error_TYPE == OUT_OF_STACK_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_gcl(LOCAL_Error_Size, nargs, ENV, CP)) {
return false;
}
}
/* preserve value of H after scanning: otherwise we may lose strings
and floats */
old_H = HR;
if (GLOBAL_Stream[inp_stream].status & Eof_Stream_f) {
if (LOCAL_eot_before_eof || (GLOBAL_Stream[inp_stream].status & InMemory_Stream_f)) {
/* next read should give out an end of file */
GLOBAL_Stream[inp_stream].status |= Push_Eof_Stream_f;
} else {
if (tokstart != NULL && tokstart->Tok != Ord (eot_tok)) {
/* we got the end of file from an abort */
if (LOCAL_ErrorMessage &&
!strcmp(LOCAL_ErrorMessage,"Abort")) {
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
return FALSE;
}
/* we need to force the next reading to also give end of file.*/
GLOBAL_Stream[inp_stream].status |= Push_Eof_Stream_f;
LOCAL_ErrorMessage = "end of file found before end of term";
} else {
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
return Yap_unify_constant(ARG2, MkAtomTerm (AtomEof))
&& Yap_unify_constant(ARG4, TermNil);
}
}
}
// go back to the start
if (old_renv->had_ungetc) {
GLOBAL_Stream[inp_stream].stream_getc = PlUnGetc;
GLOBAL_Stream[inp_stream].och = old_renv->ungetc_oldc;
}
if (old_renv->seekable) {
if (GLOBAL_Stream[inp_stream].status & InMemory_Stream_f) {
GLOBAL_Stream[inp_stream].u.mem_string.pos = old_renv->cpos;
} else if (GLOBAL_Stream[inp_stream].status) {
#if HAVE_FGETPOS
fsetpos(GLOBAL_Stream[inp_stream].file, &old_renv->rpos);
#else
fseek(GLOBAL_Stream[inp_stream].file, old_renv->cpos, 0L);
#endif
}
if ((GLOBAL_Stream[inp_stream].status & Eof_Stream_f)) {
GLOBAL_Stream[inp_stream].status &= ~Eof_Stream_f;
GLOBAL_Stream[inp_stream].status |= Push_Eof_Stream_f;
ResetEOF(GLOBAL_Stream+inp_stream);
}
}
return true;
} else if (why == PARSER_FAILED ) {
Term ParserErrorStyle = getSyntaxErrorsFlag();
if (ParserErrorStyle == TermQuiet) {
/* just fail */
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
return false;
} else if (ParserErrorStyle ==TermDec10) {
LOCAL_ErrorMessage = NULL;
/* try again */
// notice that we will still use the original scan
return true;
} else {
Term terr = Yap_syntax_error(tokstart, inp_stream);
if (LOCAL_ErrorMessage == NULL)
LOCAL_ErrorMessage = "SYNTAX ERROR";
if (ParserErrorStyle == TermException) {
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
Yap_Error(SYNTAX_ERROR,terr,LOCAL_ErrorMessage);
return false;
} else /* FAIL ON PARSER ERROR */ {
// Term t[2];
//t[0] = terr;
//t[1] = MkAtomTerm(Yap_LookupAtom(LOCAL_ErrorMessage));
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
//return Yap_unify(Err,Yap_MkApplTerm(Yap_MkFunctor(AtomError,2),2,t));
return false;
}
}
}
return false;
}
Int
Yap_FirstLineInParse ( void )
{
CACHE_REGS
return LOCAL_StartLine;
}
static void
reset_regs(CELL *old_H, TokEntry *tokstart, tr_fr_ptr Xold_TR)
{
CACHE_REGS
tr_fr_ptr old_TR;
restore_machine_regs();
old_TR = TR;
/* restart global */
HR = old_H;
TR = (tr_fr_ptr)LOCAL_ScannerStack;
Yap_growstack_in_parser(&old_TR, &tokstart, &LOCAL_VarTable);
LOCAL_ScannerStack = (char *)TR;
TR = old_TR;
}
static bool
complete_processing( FEnv *fe, TokEntry *tokstart )
{
CACHE_REGS
Term v;
if (fe->vp) {
while (TRUE) {
CELL *old_H = HR;
tr_fr_ptr old_TR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_Variables(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs(old_H, tokstart, old_TR);
}
}
if (!Yap_unify(v, fe->vp))
return false;
}
if (fe->np) {
while (TRUE) {
CELL *old_H = HR;
tr_fr_ptr old_TR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_VarNames(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs(old_H, tokstart, old_TR);
}
}
if (!Yap_unify(v, fe->np))
return false;
}
if (fe->np) {
while (TRUE) {
CELL *old_H = HR;
tr_fr_ptr old_TR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_VarNames(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs(old_H, tokstart, old_TR);
}
}
if (!Yap_unify(v, fe->np))
return false;
}
if (fe->sp) {
while (TRUE) {
CELL *old_H = HR;
tr_fr_ptr old_TR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_Singletons(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs(old_H, tokstart, old_TR);
}
}
if (!Yap_unify(v, fe->np))
return false;
}
if (fe->tp) {
while (TRUE) {
CELL *old_H = HR;
tr_fr_ptr old_TR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = MkIntegerTerm(Yap_FirstLineInParse());
break;
} else {
reset_regs(old_H, tokstart, old_TR);
}
}
if (!Yap_unify(v, fe->tp))
return false;
}
return true;
}
/*
Assumes
Flag: ARG1
Term: ARG2
Module: ARG3
Vars: ARG4
Pos: ARG5
Err: ARG6
*/
Term Yap_read_term(int inp_stream, Term opts, int nargs)
{
CACHE_REGS
Term t;
TokEntry *tokstart;
#if EMACS
int emacs_cares = FALSE;
#endif
Term tpos;
FEnv fe;
REnv re;
bool restart = true;
CELL *old_H = HR;
tr_fr_ptr old_TR = TR;
xarg *args;
if (GLOBAL_Stream[inp_stream].status & Binary_Stream_f) {
Yap_Error(PERMISSION_ERROR_INPUT_BINARY_STREAM, MkAtomTerm(GLOBAL_Stream[inp_stream].name), "read_term/2");
return 0;
}
LOCAL_Error_TYPE = YAP_NO_ERROR;
tpos = StreamPosition(inp_stream);
LOCAL_SourceFileName = GLOBAL_Stream[inp_stream].name;
while (restart) {
LOCAL_eot_before_eof = false;
tpos = StreamPosition(inp_stream);
args = Yap_ArgListToVector ( opts, read_defs, READ_END );
if (args == NULL) {
return 0;
}
setReadEnv( args, &fe, &re, inp_stream );
old_H = HR;
old_TR = TR;
tokstart = LOCAL_tokptr = LOCAL_toktide = Yap_tokenizer(GLOBAL_Stream+inp_stream, false, &tpos);
if (tokstart->Tok == Ord(eot_tok)) {
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
return TermEof;
}
if (LOCAL_Error_TYPE != YAP_NO_ERROR) {
HR = old_H;
restart = resetReadEnv( &re, inp_stream, SCANNER_FAILED, tokstart, old_H, old_TR, nargs );
LOCAL_Error_TYPE = YAP_NO_ERROR;
LOCAL_ErrorMessage = NULL;
if (restart) {
TR = old_TR;
LOCAL_ScannerStack = (char *)TR;
old_H = HR;
LOCAL_tokptr = LOCAL_toktide = tokstart;
}
} else {
restart = false;
}
}
UInt prio;
if (args[READ_PRIORITY].used) {
prio = IntegerOfTerm(args[READ_PRIORITY].tvalue);
if (prio > 1200) {
Yap_Error(DOMAIN_ERROR_OPERATOR_PRIORITY, opts, "max priority in Prolog is 1200, not %ld", prio);
}
}else {
prio = LOCAL_default_priority;
}
while (LOCAL_ErrorMessage || (t = Yap_Parse(prio)) == 0) {
HR = old_H;
TR = (tr_fr_ptr)LOCAL_ScannerStack;
if (!resetReadEnv( &re, inp_stream, PARSER_FAILED, tokstart, old_H, old_TR, nargs ))
break;
}
complete_processing( &fe, tokstart );
#if EMACS
first_char = tokstart->TokPos;
#endif /* EMACS */
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
return t;
}
static Int
read_term2( USES_REGS1 )
{ /* '$read'(+Flag,?Term,?Module,?Vars,-Pos,-Err) */
Term rc;
if ((rc =Yap_read_term(LOCAL_c_input_stream, ARG2, 2)) == 0)
return FALSE;
return Yap_unify( ARG1, rc );
}
static Int
read_term ( USES_REGS1 )
{ /* '$read2'(+Flag,?Term,?Module,?Vars,-Pos,-Err,+Stream) */
int inp_stream;
Int out;
/* needs to change LOCAL_output_stream for write */
inp_stream = Yap_CheckStream (ARG1, Input_Stream_f, "read/3");
if (inp_stream == -1) {
return(FALSE);
}
UNLOCK(GLOBAL_Stream[inp_stream].streamlock);
out = Yap_read_term(inp_stream, ARG3, 3 );
return out && Yap_unify( ARG2, out );
}
static Int
read_clause2( USES_REGS1 )
{ /* '$read'(+Flag,?Term,?Module,?Vars,-Pos,-Err) */
Term rc;
if ((rc =Yap_read_term(LOCAL_c_input_stream, ARG2, 2)) == 0)
return FALSE;
return Yap_unify( ARG1, rc );
}
static Int
read_clause ( USES_REGS1 )
{ /* '$read2'(+Flag,?Term,?Module,?Vars,-Pos,-Err,+Stream) */
int inp_stream;
Int out;
/* needs to change LOCAL_output_stream for write */
inp_stream = Yap_CheckStream (ARG1, Input_Stream_f, "read/3");
if (inp_stream == -1) {
return(FALSE);
}
UNLOCK(GLOBAL_Stream[inp_stream].streamlock);
out = Yap_read_term(inp_stream, ARG3, 3 );
return out && Yap_unify( ARG2, out );
}
/**
* @pred source_location( - _File_ , _Line_ )
*
* unify _File_ and _Line_ wuth the position of the last term read, if the term
* comes from a stream created by opening a file-system path with open/3 and friends.
* It ignores user_input or
* sockets.
*
* @param - _File_
* @param - _Line_
*
* @note SWI-Prolog built-in.
*/
static Int
source_location ( USES_REGS1 )
{
return Yap_unify( ARG1, MkAtomTerm(LOCAL_SourceFileName)) &&
Yap_unify( ARG2, MkIntegerTerm(LOCAL_SourceFileLineno));
}
/** @pred read(+ _S_,- _T_) is iso
Reads term _T_ from the stream _S_ instead of from the current input
stream.
*/
static Int
read2 ( USES_REGS1 )
{ /* '$read2'(+Flag,?Term,?Module,?Vars,-Pos,-Err,+Stream) */
int inp_stream;
Int out;
/* needs to change LOCAL_output_stream for write */
inp_stream = Yap_CheckStream (ARG1, Input_Stream_f, "read/3");
if (inp_stream == -1) {
return(FALSE);
}
UNLOCK(GLOBAL_Stream[inp_stream].streamlock);
out = Yap_read_term(inp_stream, TermNil, 1);
return out && Yap_unify(ARG2, out);
}
/** @pred read(- _T_) is iso
Reads the next term from the current input stream, and unifies it with
_T_. The term must be followed by a dot (`.`) and any blank-character
as previously defined. The syntax of the term must match the current
declarations for operators (see op). If the end-of-stream is reached,
_T_ is unified with the atom `end_of_file`. Further reads from of
the same stream may cause an error failure (see open/3).
*/
static Int
read1 ( USES_REGS1 )
{ /* '$read2'(+Flag,?Term,?Module,?Vars,-Pos,-Err,+Stream) */
Term out = Yap_read_term(LOCAL_c_input_stream, TermNil, 1);
return out && Yap_unify(ARG1, out);
}
/** @pred fileerrors
Switches on the file_errors flag so that in certain error conditions
Input/Output predicates will produce an appropriated message and abort.
*/
static Int
fileerrors ( USES_REGS1 )
{
return setYapFlag( MkAtomTerm(AtomFileerrors), TermTrue );
}
/** @pred nofileerrors
Switches off the file_errors flag, so that the predicates see/1,
tell/1, open/3 and close/1 just fail, instead of producing
an error message and aborting whenever the specified file cannot be
opened or closed.
*/
static Int nofileerrors( USES_REGS1 )
{ /* '$read2'(+Flag,?Term,?Module,?Vars,-Pos,-Err,+Stream) */
return setYapFlag( MkAtomTerm(AtomFileerrors), TermFalse );
}
static Int style_checker( USES_REGS1 )
{
Term t = Deref( ARG1 );
CACHE_REGS
if (IsVarTerm(t)) {
Term t = TermNil;
if ( getYapFlag( MkAtomTerm(AtomSingleVarWarnings)) == TermTrue) {
t = MkPairTerm( MkAtomTerm(AtomSingleVarWarnings), t );
}
if (getYapFlag( MkAtomTerm(AtomDiscontiguousWarnings)) == TermTrue) {
t = MkPairTerm( MkAtomTerm(AtomDiscontiguousWarnings), t );
}
if ( getYapFlag( MkAtomTerm(AtomRedefineWarnings)) == TermTrue ) {
t = MkPairTerm( MkAtomTerm(AtomRedefineWarnings), t );
}
} else {
while (IsPairTerm(t)) {
Term h = HeadOfTerm( t );
t = TailOfTerm( t );
if (IsVarTerm(h)) {
Yap_Error(INSTANTIATION_ERROR, t, "style_check/1");
return (FALSE);
} else if (IsAtomTerm(h)) {
Atom at = AtomOfTerm( h );
if (at == AtomSingleVarWarnings)
setYapFlag( MkAtomTerm(AtomSingleVarWarnings), TermTrue);
else if (at == AtomDiscontiguousWarnings)
setYapFlag( MkAtomTerm(AtomDiscontiguousWarnings), TermTrue);
else if (at == AtomRedefineWarnings)
setYapFlag( MkAtomTerm(AtomRedefineWarnings), TermTrue);
} else {
Atom at = AtomOfTerm( ArgOfTerm( 1, h ) );
if (at == AtomSingleVarWarnings)
setYapFlag( MkAtomTerm(AtomSingleVarWarnings), TermFalse);
else if (at == AtomDiscontiguousWarnings)
setYapFlag( MkAtomTerm(AtomDiscontiguousWarnings), TermFalse);
else if (at == AtomRedefineWarnings)
setYapFlag( MkAtomTerm(AtomRedefineWarnings), TermFalse);
}
}
}
return TRUE;
}
Term
Yap_StringToTerm(const char *s, size_t len, encoding_t enc, int prio, Term *bindings)
{
Term bvar = MkVarTerm(), ctl;
yhandle_t sl;
CACHE_REGS
if (bindings) {
ctl = Yap_MkApplTerm( Yap_MkFunctor(AtomVariableNames,1),1,&bvar);
sl = Yap_InitSlot( bvar );
} else {
ctl = TermNil;
sl = 0;
}
Term rval;
int stream = Yap_open_buf_read_stream(s, len, enc, MEM_BUF_USER);
rval = Yap_read_term(stream, ctl, 3);
Yap_CloseStream(stream);
if (bindings) {
*bindings = Yap_GetFromSlot( sl );
Yap_RecoverSlots( sl, 1 );
}
return rval;
}
Term
Yap_ReadFromAtom(Atom a, Term opts)
{
Term rval;
int sno;
CACHE_REGS
if (IsWideAtom( a )) {
wchar_t *ws = a->WStrOfAE;
size_t len = wcslen(ws);
sno = Yap_open_buf_read_stream((char *)ws, len, ENC_ISO_ANSI, MEM_BUF_USER);
} else {
char *s = a->StrOfAE;
size_t len = strlen(s);
sno = Yap_open_buf_read_stream((char *)s, len, ENC_ISO_LATIN1, MEM_BUF_USER);
}
rval = Yap_read_term(sno, opts, 3);
Yap_CloseStream(sno);
return rval;
}
static Term
readFromBuffer(const char *s, Term opts)
{
Term rval;
int sno;
CACHE_REGS
sno = Yap_open_buf_read_stream((char *)s, utf8_strlen1(s), ENC_ISO_UTF8, MEM_BUF_USER);
rval = Yap_read_term(sno, opts, 3);
Yap_CloseStream(sno);
return rval;
}
/**
* @pred read_term_from_atom( +_Atom_ , - _T_ , + _VarNames_
*
* read a term _T_ stored in constant _Atom_ and report their names
*
* @param _Atom_ the source _Atom_
* @param _T_ the output term _T_, may be any term
* @param _VarNames_ list of _Var_ = _Name_ tuples.
*
* @notes Originally from SWI-Prolog, in YAP only works with atoms.
*/
static Int
atom_to_term( USES_REGS1 )
{
Term t1 = Deref(ARG1), ctl, rc;
Atom at;
if (IsVarTerm(t1)) {
Yap_Error(INSTANTIATION_ERROR, t1, "style_check/1");
return (FALSE);
} else if (!IsAtomTerm(t1)) {
Yap_Error(TYPE_ERROR_ATOM, t1, "style_check/1");
return (FALSE);
} else {
at = AtomOfTerm( t1 );
}
Term bvar = MkVarTerm();
Yap_unify( ARG3, bvar );
ctl = Yap_MkApplTerm( Yap_MkFunctor(AtomVariableNames,1),1,&bvar);
if ((rc = Yap_ReadFromAtom( at, ctl)) == 0L)
return false;
return Yap_unify( rc, ARG2 );
}
/**
* @pred read_term_from_atom( +_Atom_ , - _T_ , + _Options_
*
* read a term _T_ stored in constant _Atom_ according to _Options_
*
* @param _Atom_ the source _Atom_
* @param _T_ the output term _T_, may be any term
* @param _Options_ read_term/3 options.
*
* @notes Originally from SWI-Prolog, in YAP only works with internalised atoms
* Check read_term_from_atomic/3 for the general version. Also, the built-in is supposed to
* use YAP's internal encoding, so please avoid the encoding/1 option.
*/ static Int
read_term_from_atom( USES_REGS1 )
{
Term t1 = Deref(ARG1), rc;
Atom at;
if (IsVarTerm(t1)) {
Yap_Error(INSTANTIATION_ERROR, t1, "style_check/1");
return (FALSE);
} else if (!IsAtomTerm(t1)) {
Yap_Error(TYPE_ERROR_ATOM, t1, "style_check/1");
return (FALSE);
} else {
at = AtomOfTerm( t1 );
}
if ((rc = Yap_ReadFromAtom( at, Deref(ARG3))) == 0L)
return false;
return Yap_unify( rc, ARG2 );
}
/**
* @pred read_term_from_string( +_String_ , - _T_ , + _Options_
*
* read a term _T_ stored in constant _String_ according to _Options_
*
* @param _String_ the source _String_
* @param _T_ the output term _T_, may be any term
* @param _Options_ read_term/3 options.
*
* @notes Idea from SWI-Prolog, in YAP only works with strings
* Check read_term_from_atomic/3 for the general version.
*/ static Int
read_term_from_string( USES_REGS1 )
{
Term t1 = Deref(ARG1), rc;
const char *s;
size_t len;
if (IsVarTerm(t1)) {
Yap_Error(INSTANTIATION_ERROR, t1, "read_term_from_string/3");
return (FALSE);
} else if (!IsStringTerm(t1)) {
Yap_Error(TYPE_ERROR_STRING, t1, "read_term_from_string/3");
return (FALSE);
} else {
s = StringOfTerm( t1 );
len = utf8_strlen1( s );
}
int sno = Yap_open_buf_read_stream(s, len, ENC_ISO_UTF8, MEM_BUF_USER);
rc = readFromBuffer( s, Deref(ARG3) );
Yap_CloseStream(sno);
if (!rc)
return false;
return Yap_unify( rc, ARG2 );
}
/**
* @pred read_term_from_atomic( +_Atomic_ , - _T_ , + _Options_
*
* read a term _T_ stored in text _Atomic_ according to _Options_
*
* @param _Atomic_ the source may be an atom, string, list of codes, or list of chars.
* @param _T_ the output term _T_, may be any term
* @param _Options_ read_term/3 options.
*
* @notes Idea originally from SWI-Prolog, but in YAP we separate atomic and atom.
* Encoding is fixed in atoms and strings.
*/ static Int
read_term_from_atomic( USES_REGS1 )
{
Term t1 = Deref(ARG1), rc;
const char *s;
size_t len;
if (IsVarTerm(t1)) {
Yap_Error(INSTANTIATION_ERROR, t1, "read_term_from_atomic/3");
return (FALSE);
} else if (!IsAtomicTerm(t1)) {
Yap_Error(TYPE_ERROR_ATOMIC, t1, "read_term_from_atomic/3");
return (FALSE);
} else {
Term t = Yap_AtomicToString(t1 PASS_REGS);
s = StringOfTerm( t );
len = utf8_strlen1( s );
}
int sno = Yap_open_buf_read_stream(s, len, ENC_ISO_UTF8, MEM_BUF_USER);
rc = readFromBuffer( s, Deref(ARG3) );
Yap_CloseStream(sno);
if (!rc)
return false;
return Yap_unify( rc, ARG2 );
}
void
Yap_InitReadTPreds(void)
{
Yap_InitCPred ("read", 1, read1, SyncPredFlag);
Yap_InitCPred ("read", 2, read2, SyncPredFlag);
Yap_InitCPred ("read_term", 2, read_term2, SyncPredFlag);
Yap_InitCPred ("read_term", 3, read_term, SyncPredFlag);
Yap_InitCPred ("read_clause", 2, read_clause2, SyncPredFlag);
Yap_InitCPred ("read_clause", 3, read_clause, SyncPredFlag);
Yap_InitCPred ("atom_to_term", 3, atom_to_term, 0);
Yap_InitCPred ("read_term_from_atom", 3, read_term_from_atom, 0);
Yap_InitCPred ("read_term_from_atomic", 3, read_term_from_atomic, 0);
Yap_InitCPred ("read_term_from_string", 3, read_term_from_string, 0);
Yap_InitCPred ("fileerrors", 0, fileerrors, SyncPredFlag);
Yap_InitCPred ("nofileeleerrors", 0, nofileerrors, SyncPredFlag);
Yap_InitCPred ("source_location", 2, source_location, SyncPredFlag);
Yap_InitCPred ("$style_checker", 1, style_checker, SyncPredFlag|HiddenPredFlag);
}
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