From 3c4da56af2fe818cdb7bf7f82bc360790a977162 Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Mon, 13 Dec 2010 12:38:37 +0000
Subject: [PATCH] allow write to find out about SWI streams in SWI mode.

---
 C/iopreds.c                   |  22 +++++-
 H/YapHeap.h                   |   1 +
 H/Yapproto.h                  |   1 +
 H/dglobals.h                  |   1 +
 H/hglobals.h                  |   1 +
 H/iglobals.h                  |   1 +
 H/rglobals.h                  |   1 +
 H/yapio.h                     |  13 ++--
 include/SWI-Prolog.h          |   1 +
 library/dialect/swi.yap       |  12 +++
 library/dialect/swi/fli/swi.c |  10 +++
 misc/GLOBALS                  |   1 +
 packages/PLStream/pl-file.c   |  18 +++--
 pl/yio.yap                    | 139 ++++++++++++++--------------------
 14 files changed, 126 insertions(+), 96 deletions(-)

diff --git a/C/iopreds.c b/C/iopreds.c
index 61e884450..923bfb4a0 100644
--- a/C/iopreds.c
+++ b/C/iopreds.c
@@ -3487,9 +3487,17 @@ CheckStream (Term arg, int kind, char *msg)
 	sname = AtomUserOut;
       }
     }
+    if (kind & SWI_Stream_f) {
+      struct io_stream *swi_stream;
+
+      if (Yap_get_stream_handle(arg, &swi_stream)) {
+	sno = LookupSWIStream(swi_stream);
+	return sno;
+      }       
+    }
     if ((sno = CheckAlias(sname)) == -1) {
       Yap_Error(EXISTENCE_ERROR_STREAM, arg, msg);
-      return(-1);
+      return -1;
     }
   } else if (IsApplTerm (arg) && FunctorOfTerm (arg) == FunctorStream) {
     arg = ArgOfTerm (1, arg);
@@ -4087,7 +4095,15 @@ static Int
 p_write2_prio (void)
 {				/* '$write'(+Stream,+Flags,?Term) */
   int old_output_stream = Yap_c_output_stream;
-  Yap_c_output_stream = CheckStream (ARG1, Output_Stream_f, "write/2");
+  Int flags = IntegerOfTerm(Deref(ARG2));
+  int stream_f;
+
+  if (flags & Use_SWI_Stream_f) {
+    stream_f = Output_Stream_f|SWI_Stream_f;
+  } else {
+    stream_f = Output_Stream_f;
+  }
+  Yap_c_output_stream = CheckStream (ARG1, stream_f, "write/2");
   if (Yap_c_output_stream == -1) {
     Yap_c_output_stream = old_output_stream;
     return(FALSE);
@@ -4096,7 +4112,7 @@ p_write2_prio (void)
   /* notice: we must have ASP well set when using portray, otherwise
      we cannot make recursive Prolog calls */
   Yap_StartSlots();
-  Yap_plwrite (ARG4, Stream[Yap_c_output_stream].stream_wputc, (int) IntOfTerm (Deref (ARG2)), (int) IntOfTerm (Deref (ARG3)));
+  Yap_plwrite (ARG4, Stream[Yap_c_output_stream].stream_wputc, (int) flags, (int) IntOfTerm (Deref (ARG3)));
   Yap_CloseSlots();
   Yap_c_output_stream = old_output_stream;
   if (EX != 0L) {
diff --git a/H/YapHeap.h b/H/YapHeap.h
index ec52098d2..fe815007a 100755
--- a/H/YapHeap.h
+++ b/H/YapHeap.h
@@ -28,6 +28,7 @@ typedef int (*SWI_PutWideFunction)(int, void *);
 typedef int (*SWI_GetWideFunction)(void *);
 typedef int (*SWI_CloseFunction)(void *);
 typedef int (*SWI_FlushFunction)(void *);
+typedef int (*SWI_PLGetStreamFunction)(void *);
 
 #include "../include/dswiatoms.h"
 
diff --git a/H/Yapproto.h b/H/Yapproto.h
index f5e0812c0..055075eca 100755
--- a/H/Yapproto.h
+++ b/H/Yapproto.h
@@ -461,6 +461,7 @@ void    STD_PROTO(Yap_InitMYDDAS_TopLevelPreds,(void));
 /* yap2swi.c */
 void	STD_PROTO(Yap_swi_install,(void));
 void    STD_PROTO(Yap_InitSWIHash,(void));
+int     STD_PROTO(Yap_get_stream_handle,(Term, void *));
 
 /* ypsocks.c */
 void	STD_PROTO(Yap_InitSockets,(void));
diff --git a/H/dglobals.h b/H/dglobals.h
index b65cf8a51..36d72d2b4 100644
--- a/H/dglobals.h
+++ b/H/dglobals.h
@@ -187,6 +187,7 @@
 #define SWIWidePutc Yap_global->swi_wputc
 #define SWIClose Yap_global->swi_close
 #define SWIFlush Yap_global->swi_flush
+#define SWIGetStream Yap_global->swi_get_stream_f
 
 #define Yap_AllowLocalExpansion Yap_global->allow_local_expansion
 #define Yap_AllowGlobalExpansion Yap_global->allow_global_expansion
diff --git a/H/hglobals.h b/H/hglobals.h
index c14707c6f..1e60fbbf0 100644
--- a/H/hglobals.h
+++ b/H/hglobals.h
@@ -189,6 +189,7 @@ typedef struct worker_shared {
   SWI_PutWideFunction  swi_wputc;
   SWI_CloseFunction  swi_close;
   SWI_FlushFunction  swi_flush;
+  SWI_PLGetStreamFunction  swi_get_stream_f;
 
   int  allow_local_expansion;
   int  allow_global_expansion;
diff --git a/H/iglobals.h b/H/iglobals.h
index 24e0db95d..978c91658 100644
--- a/H/iglobals.h
+++ b/H/iglobals.h
@@ -187,6 +187,7 @@ static void InitGlobal(void) {
   Yap_global->swi_wputc = NULL;
   Yap_global->swi_close = NULL;
   Yap_global->swi_flush = NULL;
+  Yap_global->swi_get_stream_f = NULL;
 
   Yap_global->allow_local_expansion = TRUE;
   Yap_global->allow_global_expansion = TRUE;
diff --git a/H/rglobals.h b/H/rglobals.h
index 304992160..81d3bb0e2 100644
--- a/H/rglobals.h
+++ b/H/rglobals.h
@@ -198,6 +198,7 @@ static void RestoreGlobal(void) {
 
 
 
+
 #if HAVE_LIBREADLINE
 
 
diff --git a/H/yapio.h b/H/yapio.h
index 6cb463f09..6483a0b34 100644
--- a/H/yapio.h
+++ b/H/yapio.h
@@ -334,12 +334,13 @@ Atom	STD_PROTO(Yap_LookupWideAtom,(wchar_t *));
 #define YAP_SEEKABLE_STREAM	0x80
 
 
-#define	Quote_illegal_f		1
-#define	Ignore_ops_f		2
-#define	Handle_vars_f		4
-#define	Use_portray_f		8
-#define	To_heap_f	       16
-#define	Unfold_cyclics_f       32
+#define	Quote_illegal_f		0x01
+#define	Ignore_ops_f		0x02
+#define	Handle_vars_f		0x04
+#define	Use_portray_f		0x08
+#define	To_heap_f	        0x10
+#define	Unfold_cyclics_f        0x20
+#define	Use_SWI_Stream_f        0x40
 
 /* write.c */
 void	STD_PROTO(Yap_plwrite,(Term,int (*)(int, wchar_t), int, int));
diff --git a/include/SWI-Prolog.h b/include/SWI-Prolog.h
index 6c2863b30..a3b301169 100755
--- a/include/SWI-Prolog.h
+++ b/include/SWI-Prolog.h
@@ -698,6 +698,7 @@ typedef struct SWI_IO {
   void *put_w;
   void *flush_s;
   void *close_s;
+  void *get_stream_handle;
 } swi_io_struct;
 
 /*  SWI stream info */
diff --git a/library/dialect/swi.yap b/library/dialect/swi.yap
index 65a9e3417..a31997aa7 100755
--- a/library/dialect/swi.yap
+++ b/library/dialect/swi.yap
@@ -227,6 +227,18 @@ goal_expansion('$mark_executable'(A), system:'swi_is_absolute_file_name'(A)) :-
 goal_expansion('$absolute_file_name'(A,B),system:'swi_$absolute_file_name'(A,B)) :- swi_io.
 goal_expansion(nl(A),system:swi_nl(A)) :- swi_io.
 goal_expansion(nl,system:swi_nl) :- swi_io.
+goal_expansion(write(A),write_term(user_output,A,[swi(true)])) :- swi_io.
+goal_expansion(write(S,A),write_term(S,A,[swi(true)])) :- swi_io.
+goal_expansion(writeq(A),write_term(user_output,A,[swi(true),quoted(true)])) :- swi_io.
+goal_expansion(writeq(S,A),write_term(S,A,[swi(true),quoted(true)])) :- swi_io.
+goal_expansion(display(A),write_term(user_output,A,[swi(true),ignore_ops(true)])) :- swi_io.
+goal_expansion(display(S,A),write_term(S,A,[swi(true),ignore_ops(true),quoted(true)])) :- swi_io.
+goal_expansion(write_canonical(A),write_term(user_output,A,[swi(true),ignore_ops(true),quoted(true)])) :- swi_io.
+goal_expansion(write_canonical(S,A),write_term(S,A,[swi(true),ignore_ops(true)])) :- swi_io.
+goal_expansion(print(A),write_term(user_output,A,[swi(true),portray(true),numbervars(true)])) :- swi_io.
+goal_expansion(print(S,A),write_term(S,A,[swi(true),portray(true),numbervars(true)])) :- swi_io.
+goal_expansion(write_term(A,Opts),write_term(user_output,A,Opts,[swi(true)|Opts])) :- swi_io.
+goal_expansion(write_term(S,A,Opts),write_term(S,A,[swi(true)|Opts])) :- swi_io, \+ member(swi(_), Opts).
 
 
 % make sure we also use 
diff --git a/library/dialect/swi/fli/swi.c b/library/dialect/swi/fli/swi.c
index 337c797ff..fd4a45264 100755
--- a/library/dialect/swi/fli/swi.c
+++ b/library/dialect/swi/fli/swi.c
@@ -3103,6 +3103,16 @@ PL_YAP_InitSWIIO(struct SWI_IO *swio)
   SWIWidePutc = swio->put_w;
   SWIFlush = swio->flush_s;
   SWIClose = swio->close_s;
+  SWIGetStream = swio->get_stream_handle;
+}
+
+typedef int     (*GetStreamF)(term_t, IOSTREAM **s);
+
+int 
+Yap_get_stream_handle(Term t0, void *s){
+  term_t t = (term_t)YAP_InitSlot(t0);
+  GetStreamF f = (GetStreamF)SWIGetStream;
+  return (*f)(t,s);
 }
 
 
diff --git a/misc/GLOBALS b/misc/GLOBALS
index c1df5ec57..4313b1f87 100644
--- a/misc/GLOBALS
+++ b/misc/GLOBALS
@@ -210,6 +210,7 @@ SWI_GetWideFunction	swi_wgetc		SWIWideGetc	=NULL
 SWI_PutWideFunction	swi_wputc		SWIWidePutc	=NULL
 SWI_CloseFunction	swi_close		SWIClose	=NULL
 SWI_FlushFunction	swi_flush		SWIFlush	=NULL
+SWI_PLGetStreamFunction	swi_get_stream_f	SWIGetStream	=NULL
 
 // stack overflow expansion/gc control
 int		allow_local_expansion	Yap_AllowLocalExpansion =TRUE
diff --git a/packages/PLStream/pl-file.c b/packages/PLStream/pl-file.c
index ae4aa4cfe..c36e064b7 100755
--- a/packages/PLStream/pl-file.c
+++ b/packages/PLStream/pl-file.c
@@ -509,14 +509,13 @@ noent:
 #define get_stream_handle(t, sp, flags) \
 	get_stream_handle__LD(t, sp, flags PASS_LD)
 
-int
+X_API int
 PL_get_stream_handle(term_t t, IOSTREAM **s)
 { GET_LD
   return get_stream_handle(t, s, SH_ERRORS|SH_ALIAS);
 }
 
-
-int
+X_API int
 PL_unify_stream_or_alias(term_t t, IOSTREAM *s)
 { GET_LD
   int rval;
@@ -4308,7 +4307,8 @@ BeginPredDefs(file)
 EndPredDefs
 
 #if __YAP_PROLOG__
-static pl_Sgetc(IOSTREAM *s)
+static int
+pl_Sgetc(IOSTREAM *s)
 {
   return Sgetc(s);
 }
@@ -4328,7 +4328,7 @@ pl_nl1(term_t stream)
 }
 
 static word
-pl_nl()
+pl_nl(void)
 { return pl_nl1(0);
 }
 
@@ -4339,6 +4339,13 @@ static const PL_extension foreigns[] = {
   FRG((char *)NULL,		0, NULL,			0)
 };
 
+static int
+get_stream_handle_no_errors(term_t t, IOSTREAM **s)
+{ GET_LD
+  return get_stream_handle(t, s, SH_ALIAS);
+}
+
+
 static void
 init_yap_extras(void)
 {
@@ -4351,6 +4358,7 @@ init_yap_extras(void)
   swiio.put_w = Sputcode;
   swiio.flush_s = Sflush;
   swiio.close_s = Sclose;
+  swiio.get_stream_handle = get_stream_handle_no_errors;
   PL_YAP_InitSWIIO(&swiio);
   initCharTypes();
   initFiles();
diff --git a/pl/yio.yap b/pl/yio.yap
index 9472e01f2..200e185b0 100644
--- a/pl/yio.yap
+++ b/pl/yio.yap
@@ -29,13 +29,6 @@ open(File0,Mode,Stream) :-
 	'$expand_filename'(Expansion, File0, File),
 	'$open'(File, Mode, Stream, 16, Encoding, File0).
 
-/* meaning of flags for '$write' is
-	 1	quote illegal atoms
-	 2	ignore operator declarations
-	 4	output '$VAR'(N) terms as A, B, C, ...
-	 8	use portray(_)
-*/
-
 close(V) :- var(V), !,
 	'$do_error'(instantiation_error,close(V)).
 close(File) :-
@@ -229,21 +222,23 @@ open(F,T,S,Opts) :-
 '$check_opt_write'(attributes(T), G) :- !,
 	'$check_write_attributes'(T, G).
 '$check_opt_write'(cycles(T), G) :- !,
-	'$check_cycles_arg'(T, G).
+	'$check_boolean'(T, write_option, cycles(T), G).
 '$check_opt_write'(quoted(T), G) :- !,
-	'$check_write_quoted_arg'(T, G).
+	'$check_boolean'(T, write_option, quoted(T), G).
 '$check_opt_write'(ignore_ops(T), G) :- !,
-	'$check_write_ignore_ops_arg'(T, G).
-'$check_opt_write'(numbervars(T), G) :- !,
-	'$check_write_numbervars_arg'(T, G).
-'$check_opt_write'(portrayed(T), G) :- !,
-	'$check_write_portrayed'(T, G).
-'$check_opt_write'(portray(T), G) :- !,
-	'$check_write_portrayed'(T, G).
-'$check_opt_write'(priority(T), G) :- !,
-	'$check_priority_arg'(T, G).
+	'$check_boolean'(T, write_option, ignore_ops(T), G).
 '$check_opt_write'(max_depth(T), G) :- !,
 	'$check_write_max_depth'(T, G).
+'$check_opt_write'(numbervars(T), G) :- !,
+	'$check_boolean'(T, write_option, ignore_ops(T), G).
+'$check_opt_write'(portrayed(T), G) :- !,
+	'$check_boolean'(T, write_option, portrayed(T), G).
+'$check_opt_write'(portray(T), G) :- !,
+	'$check_boolean'(T, write_option, portray(T), G).
+'$check_opt_write'(priority(T), G) :- !,
+	'$check_priority_arg'(T, G).
+'$check_opt_write'(swi(T), G) :- !,
+	'$check_boolean'(T, write_option, swi(T), G).
 '$check_opt_write'(A, G) :-
 	'$do_error'(domain_error(write_option,A),G).
 
@@ -329,40 +324,12 @@ open(F,T,S,Opts) :-
 '$check_write_attributes'(X,G) :-
 	'$do_error'(domain_error(write_option,attributes(X)),G).
 
-'$check_write_quoted_arg'(X, G) :- var(X), !,
+'$check_boolean'(X, _, _, G) :- var(X), !,
 	'$do_error'(instantiation_error,G).
-'$check_write_quoted_arg'(true,_) :- !.
-'$check_write_quoted_arg'(false,_) :- !.
-'$check_write_quoted_arg'(X,G) :-
-	'$do_error'(domain_error(write_option,write_quoted(X)),G).
-
-'$check_cycles_arg'(X, G) :- var(X), !,
-	'$do_error'(instantiation_error,G).
-'$check_cycles_arg'(true,_) :- !.
-'$check_cycles_arg'(false,_) :- !.
-'$check_cycles_arg'(X,G) :-
-	'$do_error'(domain_error(write_option,cycles(X)),G).
-
-'$check_write_ignore_ops_arg'(X, G) :- var(X), !,
-	'$do_error'(instantiation_error,G).
-'$check_write_ignore_ops_arg'(true,_) :- !.
-'$check_write_ignore_ops_arg'(false,_) :- !.
-'$check_write_ignore_ops_arg'(X,G) :-
-	'$do_error'(domain_error(write_option,ignore_ops(X)),G).
-
-'$check_write_numbervars_arg'(X, G) :- var(X), !,
-	'$do_error'(instantiation_error,G).
-'$check_write_numbervars_arg'(true,_) :- !.
-'$check_write_numbervars_arg'(false,_) :- !.
-'$check_write_numbervars_arg'(X,G) :-
-	'$do_error'(domain_error(write_option,numbervars(X)),G).
-
-'$check_write_portrayed'(X, G) :- var(X), !,
-	'$do_error'(instantiation_error,G).
-'$check_write_portrayed'(true,_) :- !.
-'$check_write_portrayed'(false,_) :- !.
-'$check_write_portrayed'(X,G) :-
-	'$do_error'(domain_error(write_option,portrayed(X)),G).
+'$check_boolean'(true,_,_,_) :- !.
+'$check_boolean'(false,_,_,_) :- !.
+'$check_boolean'(X,B,T,G) :-
+	'$do_error'(domain_error(B,T),G).
 
 '$check_write_max_depth'(X, G) :- var(X), !,
 	'$do_error'(instantiation_error,G).
@@ -520,19 +487,20 @@ read_term(Stream, T, Options) :-
 '$add_singleton_if_no_underscore'(Na,V2,NSs,[(Name=V2)|NSs]) :-
 	atom_codes(Name, Na).
 
+nl(Stream) :- '$put'(Stream,10).
+
+nl :- current_output(Stream), '$put'(Stream,10), fail.
+nl.
+
 /* meaning of flags for '$write' is
 	 1	quote illegal atoms
 	 2	ignore operator declarations
 	 4	output '$VAR'(N) terms as A, B, C, ...
 	 8	use portray(_)
+
+   flags are defined in yapio.h
 */
 
-
-nl(Stream) :- '$put'(Stream,10).
-
-nl :- current_output(Stream), '$put'(Stream,10), fail.
-nl.
-
 write(T) :- '$write'(4, T).
 
 writeln(T) :-
@@ -563,6 +531,15 @@ write_canonical(Stream,T) :-
 	fail.
 write_canonical(_,_).
 
+print(T) :- '$write'(12,T), fail.
+print(_).
+
+print(Stream,T) :-
+	'$write'(Stream,12,T),
+	fail.
+print(_,_).
+
+
 write_term(T,Opts) :-
 	'$check_io_opts'(Opts, write_term(T,Opts)),
 	'$process_wt_opts'(Opts, 0, Flag, Priority, Callbacks),
@@ -579,42 +556,49 @@ write_term(S, T, Opts) :-
 	fail.
 write_term(_,_,_).
 
+
 '$process_wt_opts'([], Flag, Flag, 1200, []).
 '$process_wt_opts'([quoted(true)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 \/ 1,
+	FlagI is Flag0 \/ 0x01,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([quoted(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 /\ 30,
-	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
-'$process_wt_opts'([cycles(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 \/ 16,
-	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
-'$process_wt_opts'([cycles(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 /\ 15,
+	FlagI is Flag0 /\ \0x01,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([ignore_ops(true)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 \/ 2,
+	FlagI is Flag0 \/ 0x02,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([ignore_ops(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 /\ 39,
+	FlagI is Flag0 /\ \0x02,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([numbervars(true)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 \/ 4,
+	FlagI is Flag0 \/ 0x04,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([numbervars(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 /\ 27,
+	FlagI is Flag0 /\ \0x04,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([portrayed(true)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 \/ 8,
+	FlagI is Flag0 \/ 0x08,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([portrayed(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 /\ 23,
+	FlagI is Flag0 /\ \0x08,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([portray(true)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 \/ 8,
+	FlagI is Flag0 \/ 0x08,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([portray(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
-	FlagI is Flag0 /\ 23,
+	FlagI is Flag0 /\ \0x08,
+	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
+'$process_wt_opts'([cycles(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
+	FlagI is Flag0 \/ 0x20,
+	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
+'$process_wt_opts'([cycles(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
+	FlagI is Flag0 /\ \0x20,
+	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
+'$process_wt_opts'([swi(true)|Opts], Flag0, Flag, Priority, CallBacks) :-
+	FlagI is Flag0 \/ 0x40,
+	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
+'$process_wt_opts'([swi(false)|Opts], Flag0, Flag, Priority, CallBacks) :-
+	FlagI is Flag0 /\ \0x40,
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
 '$process_wt_opts'([attributes(_)|Opts], Flag0, Flag, Priority, CallBacks) :-
 	'$process_wt_opts'(Opts, FlagI, Flag, Priority, CallBacks).
@@ -632,15 +616,6 @@ write_term(_,_,_).
 	'$process_wt_callbacks'(Cs).
 
 
-print(T) :- '$write'(12,T), fail.
-print(_).
-
-print(Stream,T) :-
-	'$write'(Stream,12,T),
-	fail.
-print(_,_).
-
-
 format(T) :-
 	format(T, []).