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yap-6.3/os/readterm.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: 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 "YapFlags.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;
Term 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()
} read_choices_t;
#undef PAR
#define PAR(x,y,z) { x , y, z }
static const param_t read_defs[] =
{
READ_DEFS()
};
#undef PAR
/**
* Syntax Error Handler
*
* @par tokptr: the sequence of tokens
* @par sno: the stream numbet
*
* Implicit arguments:
* +
*/
Term
Yap_syntax_error (TokEntry * errtok, int sno)
{
CACHE_REGS
Term info;
Term startline, errline, endline;
Term tf[5];
Term *tailp = tf+4;
CELL *Hi = HR;
UInt count = 0;
Term tcount = MkIntegerTerm(count);
TokEntry * tok = LOCAL_tokptr;
Int cline = tok->TokPos;
*tailp = TermNil;
startline = MkIntegerTerm(cline);
clean_vars(LOCAL_VarTable);
clean_vars(LOCAL_AnonVarTable);
if (errtok != LOCAL_toktide) {
errtok = LOCAL_toktide;
}
errline = MkIntegerTerm( errtok->TokPos );
while (tok) {
Term ts[2];
if (HR > ASP-1024) {
tf[4] = TermNil;
errline = MkIntegerTerm(0);
endline = MkIntegerTerm( 0 );
count = 0;
/* for some reason moving this earlier confuses gcc on solaris */
HR = Hi;
break;
}
if (tok->TokPos != cline) {
*tailp = MkPairTerm(MkAtomTerm(AtomNil),TermNil);
tailp = RepPair(*tailp)+1;
}
if (tok == errtok && tok->Tok != Error_tok) {
*tailp = MkPairTerm(MkAtomTerm(AtomError),TermNil);
tailp = RepPair(*tailp)+1;
}
info = tok->TokInfo;
switch (tok->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,&(tok->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 String_tok:
{
Term t0 = Yap_CharsToTDQ((char *)info, CurrentModule PASS_REGS);
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomString,1),1,&t0);
}
break;
case WString_tok:
{
Term t0 = Yap_WCharsToTDQ((wchar_t *)info, CurrentModule PASS_REGS);
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomString,1),1,&t0);
}
break;
case BQString_tok:
{
Term t0 = Yap_CharsToTBQ((char *)info, CurrentModule PASS_REGS);
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomString,1),1,&t0);
}
break;
case WBQString_tok:
{
Term t0 = Yap_WCharsToTBQ((wchar_t *)info, CurrentModule PASS_REGS);
ts[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomString,1),1,&t0);
}
break;
case Error_tok:
{
ts[0] = MkAtomTerm(AtomError);
}
break;
case eot_tok:
endline = MkIntegerTerm(tok->TokPos);
ts[0] = MkAtomTerm(AtomDot);
break;
case Ponctuation_tok:
{
char s[2];
s[1] = '\0';
if ((info) == 'l') {
s[0] = '(';
} else {
s[0] = (char)info;
}
ts[0] = MkAtomTerm(Yap_LookupAtom(s));
}
}
tok = tok->TokNext;
if (!tok)
break;
*tailp = MkPairTerm(ts[0], TermNil);
tailp = RepPair(*tailp)+1;
}
{
Term t[3];
tf[0] = Yap_MkApplTerm(Yap_MkFunctor(AtomRead,1),1,&tcount);
t[0] = startline;
t[1] = errline;
t[2] = endline;
tf[1] = Yap_MkApplTerm(Yap_MkFunctor(AtomBetween,3),3,t);
}
/* 0: id */
/* 1: strat, error, end line */
/*2 msg */
if (LOCAL_ErrorMessage)
tf[2] = MkStringTerm(LOCAL_ErrorMessage);
else
tf[2] = MkStringTerm("");
/* file */
tf[3] = Yap_StreamUserName(sno);
/* tf[4] = ; */
return(Yap_MkApplTerm(FunctorSyntaxError,5,tf));
}
typedef struct FEnv {
Term qq, tp, sp, np, vp, ce;
Term tpos; /// initial position of the term to be read.
Term t; /// the output term
TokEntry *tokstart; /// the token list
TokEntry *toklast; /// the last token
CELL *old_H; /// initial H, will be reset on stack overflow.
tr_fr_ptr old_TR; /// initial TR
xarg *args; /// input args
bool reading_clause; /// read_clause
size_t nargs; /// arity of current procedure
} FEnv;
typedef struct renv {
Term cm, bq;
bool ce, sw;\
Term sy;
UInt cpos;
#if HAVE_FGETPOS
fpos_t rpos;
#endif
int prio;
int ungetc_oldc;
int had_ungetc;
bool seekable;
} REnv;
static xarg * setClauseReadEnv(Term opts, FEnv *fe, struct renv *re, int inp_stream);
static xarg * setReadEnv(Term opts, FEnv *fe, struct renv *re, int inp_stream)
{
CACHE_REGS
re->cm = CurrentModule;
xarg * args = Yap_ArgListToVector ( opts, read_defs, READ_END );
if (args == NULL) {
return NULL;
}
re->bq = getBackQuotesFlag();
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 if (args[READ_SINGLETONS].used) {
fe->sp = MkVarTerm();
} else {
fe->sp = 0;
}
if (args[READ_SYNTAX_ERRORS].used) {
re->sy = args[READ_SYNTAX_ERRORS].tvalue;
} else {
re->sy = TermError; // getYapFlag( MkAtomTerm(AtomSyntaxErrors) );
}
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;
}
re->seekable = (GLOBAL_Stream[inp_stream].status & Seekable_Stream_f) != 0;
if (re->seekable) {
if (GLOBAL_Stream[inp_stream].stream_getc == PlUnGetc) {
re->had_ungetc = TRUE;
re->ungetc_oldc = GLOBAL_Stream[inp_stream].och;
}
#if HAVE_FGETPOS
fgetpos(GLOBAL_Stream[inp_stream].file, &re->rpos);
#else
re->cpos = GLOBAL_Stream[inp_stream].charcount;
#endif
}
if (args[READ_PRIORITY].used) {
re->prio = IntegerOfTerm(args[READ_PRIORITY].tvalue);
if (re->prio > 1200) {
Yap_Error(DOMAIN_ERROR_OPERATOR_PRIORITY, opts, "max priority in Prolog is 1200, not %ld", re->prio);
}
}else {
re->prio = LOCAL_default_priority;
}
return args;
}
typedef enum {
YAP_START_PARSING, /// initialization
YAP_SCANNING, /// input to list of tokens
YAP_SCANNING_ERROR, /// serious error (eg oom); trying error handling, followd by either restart or failure
YAP_PARSING, /// list of tokens to term
YAP_PARSING_ERROR, /// oom or syntax error
YAP_PARSING_FINISHED /// exit parser
} parser_state_t;
Int
Yap_FirstLineInParse ( void )
{
CACHE_REGS
return LOCAL_StartLineCount;
}
static void
reset_regs( TokEntry *tokstart, FEnv *fe)
{
CACHE_REGS
restore_machine_regs();
/* restart global */
HR = fe->old_H;
TR = (tr_fr_ptr)LOCAL_ScannerStack;
Yap_growstack_in_parser(&fe->old_TR, &tokstart, &LOCAL_VarTable);
LOCAL_ScannerStack = (char *)TR;
TR = fe->old_TR;
}
static bool
complete_clause_processing( FEnv *fe, TokEntry *tokstarts, Term t );
static bool
complete_processing( FEnv *fe, TokEntry *tokstart )
{
CACHE_REGS
Term v;
if (fe->vp) {
while (TRUE) {
fe->old_H = HR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_Variables(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs(tokstart, fe);
}
}
if (!Yap_unify(v, fe->vp))
return false;
}
if (fe->np) {
while (TRUE) {
fe->old_H = HR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_VarNames(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs(tokstart, fe);
}
}
if (!Yap_unify(v, fe->np))
return false;
}
if (fe->sp) {
while (TRUE) {
fe->old_H = HR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_Singletons(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs(tokstart, fe);
}
}
if (!Yap_unify(v, fe->sp))
return false;
}
if (fe->tp && !Yap_unify(fe->tpos, fe->tp)) {
return false;
}
return true;
}
static parser_state_t
initParser(Term opts, FEnv *fe, REnv *re, int inp_stream, int nargs);
static parser_state_t
parse(REnv *re, FEnv *fe, int inp_stream);
static parser_state_t
scanError(REnv *re, FEnv *fe, int inp_stream);
static parser_state_t
scanEOF( FEnv *fe, int inp_stream);
static parser_state_t
scan(REnv *re, FEnv *fe, int inp_stream);
static parser_state_t
scanEOF( FEnv *fe, int inp_stream)
{
CACHE_REGS
//bool store_comments = false;
TokEntry * tokstart =
LOCAL_tokptr;
// check for an user abort
if (tokstart != NULL && tokstart->Tok != Ord (eot_tok)) {
/* we got the end of file from an abort */
if (LOCAL_ErrorMessage &&
!strcmp(LOCAL_ErrorMessage,"Abort")) {
fe->t = 0L;
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
return YAP_PARSING_FINISHED;
}
// a :- <eof>
/* we need to force the next read 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";
return YAP_PARSING;
} else {
// <eof>
// return end_of_file
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
fe->t = MkAtomTerm (AtomEof);
if (fe->np && !Yap_unify(TermNil, fe->np))
fe->t = 0;
if (fe->sp && !Yap_unify(TermNil, fe->sp))
fe->t = 0;
if (fe->vp && !Yap_unify(TermNil, fe->vp))
fe->t = 0;
if (fe->tp && !Yap_unify(fe->tp , fe->tpos))
fe->t = 0;
post_process_eof(GLOBAL_Stream + inp_stream);
#if DEBUG
if (GLOBAL_Option['p' - 'a' + 1]) {
fprintf(stderr, "[ end_of_file %p ]\n", GLOBAL_Stream[inp_stream].name);
}
#endif
TR = (tr_fr_ptr)LOCAL_ScannerStack;
return YAP_PARSING_FINISHED;
}
}
static parser_state_t
initParser(Term opts, FEnv *fe, REnv *re, int inp_stream, int nargs)
{
CACHE_REGS
fe->old_H = HR;
LOCAL_ErrorMessage = NULL;
fe->old_TR = TR;
LOCAL_Error_TYPE = YAP_NO_ERROR;
LOCAL_SourceFileName = GLOBAL_Stream[inp_stream].name;
LOCAL_eot_before_eof = false;
fe->tpos = StreamPosition(inp_stream);
fe->reading_clause = nargs < 0;
if (fe->reading_clause) {
fe->nargs = -nargs;
fe->args = setClauseReadEnv( opts, fe, re, inp_stream );
} else {
fe->nargs = nargs;
fe->args = setReadEnv( opts, fe, re, inp_stream );
}
if (GLOBAL_Stream[inp_stream].status & Push_Eof_Stream_f) {
fe->t = MkAtomTerm(AtomEof);
GLOBAL_Stream[inp_stream].status &= ~Push_Eof_Stream_f;
return YAP_PARSING_FINISHED;
}
if (!fe->args)
return YAP_PARSING_FINISHED;
return YAP_SCANNING;
}
static parser_state_t
scan(REnv *re, FEnv *fe, int inp_stream)
{
CACHE_REGS
/* preserve value of H after scanning: otherwise we may lose strings
and floats */
LOCAL_tokptr = LOCAL_toktide =
Yap_tokenizer(GLOBAL_Stream+inp_stream, false, &fe->tpos);
if (LOCAL_ErrorMessage)
return YAP_SCANNING_ERROR;
if (LOCAL_tokptr->Tok != Ord (eot_tok)) {
// next step
return YAP_PARSING;
}
return scanEOF(fe, inp_stream);
}
static parser_state_t
scanError(REnv *re, FEnv *fe, int inp_stream)
{
CACHE_REGS
fe->t = 0;
// running out of memory
if (LOCAL_Error_TYPE == OUT_OF_TRAIL_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_growtrail (sizeof(CELL) * K16, FALSE)) {
return YAP_PARSING_FINISHED;
}
} else if (LOCAL_Error_TYPE == OUT_OF_AUXSPACE_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_ExpandPreAllocCodeSpace(0, NULL, TRUE)) {
return YAP_PARSING_FINISHED;
}
} else if (LOCAL_Error_TYPE == OUT_OF_HEAP_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_growheap(FALSE, 0, NULL)) {
return YAP_PARSING_FINISHED;
}
} else if (LOCAL_Error_TYPE == OUT_OF_STACK_ERROR) {
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (!Yap_gcl(LOCAL_Error_Size, fe->nargs, ENV, CP)) {
return YAP_PARSING_FINISHED;
}
}
// go back to the start
if (re->had_ungetc) {
GLOBAL_Stream[inp_stream].stream_getc = PlUnGetc;
GLOBAL_Stream[inp_stream].och = re->ungetc_oldc;
}
if (re->seekable) {
if (GLOBAL_Stream[inp_stream].status & InMemory_Stream_f) {
GLOBAL_Stream[inp_stream].u.mem_string.pos = re->cpos;
} else if (GLOBAL_Stream[inp_stream].status) {
#if HAVE_FGETPOS
fsetpos(GLOBAL_Stream[inp_stream].file, &re->rpos);
#else
fseek(GLOBAL_Stream[inp_stream].file, re->cpos, 0L);
#endif
}
}
return YAP_SCANNING;
}
static parser_state_t
parseError(REnv *re, FEnv *fe, int inp_stream)
{
CACHE_REGS
fe->t = 0;
if (LOCAL_Error_TYPE == OUT_OF_TRAIL_ERROR ||
LOCAL_Error_TYPE == OUT_OF_AUXSPACE_ERROR ||
LOCAL_Error_TYPE == OUT_OF_HEAP_ERROR ||
LOCAL_Error_TYPE == OUT_OF_STACK_ERROR) {
return YAP_SCANNING_ERROR;
}
Term ParserErrorStyle = re->sy;
if (ParserErrorStyle == TermQuiet) {
/* just fail */
return YAP_PARSING_FINISHED;
} else {
Term terr = Yap_syntax_error(fe->toklast, inp_stream);
if (ParserErrorStyle ==TermError) {
LOCAL_ErrorMessage = "SYNTAX ERROR";
Yap_Error(SYNTAX_ERROR,terr,LOCAL_ErrorMessage);
return YAP_PARSING_FINISHED;
} else {
Yap_PrintWarning(terr);
if (ParserErrorStyle == TermDec10);
return YAP_SCANNING;
}
}
return YAP_PARSING_FINISHED;
}
static parser_state_t
parse(REnv *re, FEnv *fe, int inp_stream)
{
CACHE_REGS
TokEntry * tokstart =
LOCAL_tokptr;
fe->t = Yap_Parse(re->prio);
fe->toklast = LOCAL_tokptr;
LOCAL_tokptr = tokstart;
if (fe->t == 0 || LOCAL_ErrorMessage)
return YAP_PARSING_ERROR;
TR = (tr_fr_ptr)LOCAL_ScannerStack;
if (fe->reading_clause &&
!complete_clause_processing( fe, tokstart, fe-> t ))
fe->t = 0;
else if (!fe->reading_clause &&
!complete_processing( fe, tokstart ))
fe->t = 0;
#if EMACS
first_char = tokstart->TokPos;
#endif /* EMACS */
Yap_clean_tokenizer(tokstart, LOCAL_VarTable, LOCAL_AnonVarTable);
return YAP_PARSING_FINISHED;
}
/**
* @brief generic routine to read terms from a stream
*
*
* @arg inp_stream: where we read from
* @arg: opts, a list with options
* @arg: if called from read_term, arity
* called from read_clause, -arity
*
* @return the term or 0 in case of error.
*
* Implementation uses a state machine: default is init, scan, parse, complete.
*
*
*/
Term Yap_read_term(int inp_stream, Term opts, int nargs)
{
CACHE_REGS
FEnv fe;
REnv re;
tr_fr_ptr tr0 = TR;
#if EMACS
int emacs_cares = FALSE;
#endif
parser_state_t state = YAP_START_PARSING;
while (state != YAP_PARSING_FINISHED)
{
switch( state )
{
case YAP_START_PARSING:
state = initParser(opts, &fe, &re, inp_stream, nargs);
break;
case YAP_SCANNING:
state = scan(&re, &fe, inp_stream);
break;
case YAP_SCANNING_ERROR:
state = scanError(&re, &fe, inp_stream);
break;
case YAP_PARSING:
state = parse(&re, &fe, inp_stream);
break;
case YAP_PARSING_ERROR:
state = parseError(&re, &fe, inp_stream);
break;
case YAP_PARSING_FINISHED:
return fe.t;
}
}
TR = tr0;
return fe.t;
}
static Int
read_term2( USES_REGS1 )
{ /* '$read'(+Flag,?Term,?Module,?Vars,-Pos,-Err) */
Term rc;
yhandle_t h = Yap_InitSlot(ARG1);
if ((rc =Yap_read_term(LOCAL_c_input_stream, ARG2, 2)) == 0)
return FALSE;
return Yap_unify( Yap_GetFromSlot( h ), rc );
}
static Int
read_term ( USES_REGS1 )
{ /* '$read2'(+Flag,?Term,?Module,?Vars,-Pos,-Err,+Stream) */
int inp_stream;
Int out;
/* needs to change LOCAL_output_stream for write */
yhandle_t h = Yap_InitSlot(ARG2);
inp_stream = Yap_CheckStream (ARG1, Input_Stream_f, "read/3");
if (inp_stream == -1) {
return(FALSE);
}
out = Yap_read_term(inp_stream, ARG3, 3 );
UNLOCK(GLOBAL_Stream[inp_stream].streamlock);
return out != 0L && Yap_unify( Yap_GetFromSlot( h ), out );
}
#define READ_CLAUSE_DEFS() \
PAR( "comments", filler, READ_CLAUSE_COMMENTS), \
PAR( "process_comments", boolean, READ_CLAUSE_PROCESS_COMMENTS), \
PAR( "module", isatom, READ_CLAUSE_MODULE ), \
PAR( "variable_names", filler, READ_CLAUSE_VARIABLE_NAMES ), \
PAR( "term_position", filler, READ_CLAUSE_TERM_POSITION ), \
PAR( "syntax_errors", isatom, READ_CLAUSE_SYNTAX_ERRORS ), \
PAR( NULL, ok, READ_CLAUSE_END )
#define PAR(x,y,z) z
typedef enum read_clause_enum_choices
{
READ_CLAUSE_DEFS()
} read_clause_choices_t;
#undef PAR
#define PAR(x,y,z) { x , y, z }
static const param_t read_clause_defs[] =
{
READ_CLAUSE_DEFS()
};
#undef PAR
static xarg * setClauseReadEnv( Term opts, FEnv *fe, struct renv *re, int inp_stream)
{
CACHE_REGS
re->cm = CurrentModule;
xarg *args = Yap_ArgListToVector ( opts, read_clause_defs, READ_END );
if (args == NULL) {
return NULL;
}
re->cm = CurrentModule;
re->bq = getBackQuotesFlag();
CurrentModule = LOCAL_SourceModule;
fe->qq = 0;
if (args[READ_CLAUSE_TERM_POSITION].used) {
fe->tp = args[READ_CLAUSE_TERM_POSITION].tvalue;
} else {
fe->tp = 0;
}
if (trueLocalPrologFlag( SINGLE_VAR_WARNINGS_FLAG )) {
fe->sp = MkVarTerm();
} else {
fe->sp = 0;
}
if (args[READ_CLAUSE_SYNTAX_ERRORS].used) {
re->sy = args[READ_CLAUSE_SYNTAX_ERRORS].tvalue;
} else {
re->sy = TermDec10;
}
fe->vp = 0;
if (args[READ_CLAUSE_VARIABLE_NAMES].used) {
fe->np = args[READ_CLAUSE_VARIABLE_NAMES].tvalue;
} else {
fe->np = 0;
}
fe->ce = Yap_CharacterEscapes( CurrentModule ) ;
re->seekable = (GLOBAL_Stream[inp_stream].status & Seekable_Stream_f) != 0;
if (re->seekable) {
if (GLOBAL_Stream[inp_stream].stream_getc == PlUnGetc) {
re->had_ungetc = TRUE;
re->ungetc_oldc = GLOBAL_Stream[inp_stream].och;
}
#if HAVE_FGETPOS
fgetpos(GLOBAL_Stream[inp_stream].file, &re->rpos);
#else
re->cpos = GLOBAL_Stream[inp_stream].charcount;
#endif
}
re->prio = LOCAL_default_priority;
return args;
}
static bool
complete_clause_processing( FEnv *fe, TokEntry *tokstart, Term t )
{
CACHE_REGS
Term v;
if (fe->np) {
while (TRUE) {
fe->old_H = HR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_VarNames(LOCAL_VarTable, TermNil);
break;
} else {
reset_regs( tokstart, fe);
}
}
if (!Yap_unify(v, fe->np))
return false;
}
if (fe->sp) {
Term singls[3];
while (TRUE) {
fe->old_H = HR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = Yap_Singletons(LOCAL_VarTable, TermNil);
if (v == TermNil)
break;
singls[0] = v;
singls[1] = fe->tpos;
singls[2] = t;
if (Yap_PrintWarning(Yap_MkApplTerm(Yap_MkFunctor(AtomSingleton,3),3,singls)))
break;
} else {
reset_regs( tokstart, fe);
}
}
}
if (fe->tp) {
while (TRUE) {
fe->old_H = HR;
if (setjmp(LOCAL_IOBotch) == 0) {
v = MkIntegerTerm(Yap_FirstLineInParse());
break;
} else {
reset_regs( tokstart, fe);
}
}
if (!Yap_unify(v, fe->tp))
return false;
}
return true;
}
/**
* @pred read_clause( +_Stream_, -_Clause_, ?_Opts) is det
*
u* Same as read_clause/3, but from the standard input stream.
*
*/
static Int
read_clause2( USES_REGS1 )
{
Term rc;
yhandle_t h = Yap_InitSlot(ARG1);
rc = Yap_read_term(LOCAL_c_input_stream, Deref(ARG2), -2 );
return rc && Yap_unify( Yap_GetFromSlot( h ), rc );
}
/**
* @pred read_clause( +_Stream_, -_Clause_, ?_Opts) is det
*
* This predicate receives a set of options _OPts_ based on read_term/3, but specific
* to readin clauses. The following options are considered:
*
* + The `comments` option unifies its argument with the comments in the term,
* represented as strings
* + The `process_comments` option calls a hook, it is current ignored by YAP.
* + The `term_position` unifies its argument with a term describing the
* position of the term.
* + The `syntax_errors` flag controls response to syntactic errors, the default is `dec10`.
*
* The next two options are called implicitely:
*
* + The `module` option is initialised to the current source module, by default.
* + The `tons` option is set from the single var flag
*/
static Int
read_clause ( USES_REGS1 )
{ /* '$read2'(+Flag,?Term,?Module,?Vars,-Pos,-Err,+Stream) */
int inp_stream;
Int out;
Term t3 = Deref(ARG3);
yhandle_t h = Yap_InitSlot(ARG2);
/* needs to change LOCAL_output_stream for write */
inp_stream = Yap_CheckStream (ARG1, Input_Stream_f, "read/3");
out = Yap_read_term(inp_stream, t3, -3 );
UNLOCK(GLOBAL_Stream[inp_stream].streamlock);
return out && Yap_unify( Yap_GetFromSlot( h ), out );
}
/**
* @pred source_location( - _File_ , _Line_ )
*
* unify _File_ and _Line_ wuth the position of the last term read, if the term
* comes from a stream created by opening a file-system path with open/3 and friends.>position
* It ignores user_input or
* sockets.
*
* @param - _File_
* @param - _Line_
*
* @note SWI-Prolog built-in.
*/
static Int
source_location ( USES_REGS1 )
{
return Yap_unify( ARG1, MkAtomTerm(LOCAL_SourceFileName)) &&
Yap_unify( ARG2, MkIntegerTerm(LOCAL_SourceFileLineno));
}
/**
* @pred read(+ _Stream_, - _Term_ ) is iso
*
* Reads term _T_ from the stream _S_ instead of from the current input
* stream.
*
* @param - _Stream_
* @param - _Term_
*
*/
static Int
read2 ( USES_REGS1 )
{ /* '$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);
}
out = Yap_read_term(inp_stream, TermNil, 1);
UNLOCK(GLOBAL_Stream[inp_stream].streamlock);
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 );
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)
{
CACHE_REGS
Term bvar = MkVarTerm(), ctl;
yhandle_t sl;
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);
UNLOCK(GLOBAL_Stream[stream].streamlock);
if (rval && bindings) {
*bindings = Yap_GetFromSlot( sl );
Yap_RecoverSlots( sl, 1 PASS_REGS);
}
return rval;
}
Term
Yap_ReadFromAtom(Atom a, Term opts)
{
Term rval;
int sno;
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;
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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