prnhnd.pro

prolog,人工智能推理程序,运行环境prolog

project "register"
check_determ

include "globals.pro"

/****************************************************************

		PRINTER TOOLS
		=============

  Controls printer output. Takes care of printer initialization,
  pagelength and pageshift, indentation of leftmargin, printing
  of foothers and headers and a possible character convertion.

  Uses the global domain prn_file as printer output.

  The predicates mk_foother and mk_header should be defined globally.

  Print should be initiated by init_printer and finished by
  close_printer.

  Output should be performed by write_ch and write_str.


****************************************************************/

/* NESSECARRY GLOBAL DECLARATIONS
GLOBAL DOMAINS
  file = prn_file

GLOBAL PREDICATES
/* init_printer(MARGIN,TOPMARGIN,PAGELENGTH,CHARCONV,INITCODE,PRINTDEST) */
  determ init_printer(INTEGER,INTEGER,INTEGER,STRING,STRING,STRING)-(i,i,i,i,i,i)
  determ close_printer
  determ write_ch(CHAR) - (i)
  determ write_str(STRING) - (i)
  determ make_footer
  determ make_header
  determ check_page(STRING,INTEGER)-(i,i)
  determ shift_page()
  determ getpageno(INTEGER)-(o)
*/


/****************************************************************
	Local database used as global information during output
****************************************************************/

DATABASE - prn_dba
  prn_lineno(INTEGER)		/* Current line number			*/
  prn_pageno(INTEGER)		/* Current page number			*/
  prn_margin(INTEGER)		/* Left margin				*/
  prn_topmargin(INTEGER)	/* Noof empty toplines			*/
  prn_pagelength(INTEGER)	/* Pagelength				*/
  prn_charconv			/* Character convertion			*/


/****************************************************************
	HELP PREDICATES
****************************************************************/

PREDICATES
  printercode(STRING)
  count_lines(STRING,INTEGER,INTEGER)
  inc_lineno
  inc_lineno1(INTEGER)
  inc_pageno
  conv_char(CHAR,CHAR)
  mk_margin(integer)
  mk_topmargin(INTEGER)
  setwritedevice(STRING,STRING)

CLAUSES
  /* Interpreet escape sequences as:  "\027I\001abc"
     A backslash can be followed by an integer number
  */
  printercode(""):-!.
  printercode(CODE):-
	frontchar(CODE,'\\',REST),
	fronttoken(REST,NUM,RESTCODE),
	str_int(NUM,CHI),
	char_int(CH,CHI),
	write(CH),!,
	printercode(RESTCODE).
  printercode(CODE):-
	frontchar(CODE,CH,REST),
	write(CH),
	printercode(REST).

  count_lines("",N,N):-!.
  count_lines(STR,N,N1):-
	frontchar(STR,'\n',STR1),!,
	N2=N+1,
	count_lines(STR1,N2,N1).
  count_lines(STR,N,N1):-
	frontchar(STR,_,STR1),
	count_lines(STR1,N,N1).

  inc_lineno:-
	retract(prn_lineno(N)),!,
	inc_lineno1(N).
  inc_lineno.

  inc_lineno1(N):-
	prn_pagelength(N),!,
	shift_page.
  inc_lineno1(N):-
	N1=N+1,
	assert(prn_lineno(N1)).

  inc_pageno:-
	retract(prn_pageno(N)),!,
	N1=N+1,
	assert(prn_pageno(N1)).

  mk_margin(0):-!.
  mk_margin(N):-
	write(' '),
	N1=N-1,
	mk_margin(N1).

  conv_char('{','