Annotation of gforth/kernel/io.fs, revision 1.24

1.1       anton       1: \ input output basics                          (extra since)   02mar97jaw
                      2: 
1.24    ! anton       3: \ Copyright (C) 1995,1996,1997,1998,2000,2003 Free Software Foundation, Inc.
1.1       anton       4: 
                      5: \ This file is part of Gforth.
                      6: 
                      7: \ Gforth is free software; you can redistribute it and/or
                      8: \ modify it under the terms of the GNU General Public License
                      9: \ as published by the Free Software Foundation; either version 2
                     10: \ of the License, or (at your option) any later version.
                     11: 
                     12: \ This program is distributed in the hope that it will be useful,
                     13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
                     14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     15: \ GNU General Public License for more details.
                     16: 
                     17: \ You should have received a copy of the GNU General Public License
                     18: \ along with this program; if not, write to the Free Software
1.21      anton      19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.1       anton      20: 
1.12      jwilke     21: require ./basics.fs
                     22: 
1.2       jwilke     23: \ Output                                               13feb93py
                     24: 
1.3       jwilke     25: has? os [IF]
1.2       jwilke     26: 0 Value outfile-id ( -- file-id ) \ gforth
1.5       pazsan     27: 0 Value infile-id ( -- file-id ) \ gforth
1.7       pazsan     28:     
1.2       jwilke     29: : (type) ( c-addr u -- ) \ gforth
                     30:     outfile-id write-file drop \ !! use ?DUP-IF THROW ENDIF instead of DROP ?
                     31: ;
                     32: 
                     33: : (emit) ( c -- ) \ gforth
                     34:     outfile-id emit-file drop \ !! use ?DUP-IF THROW ENDIF instead of DROP ?
                     35: ;
1.5       pazsan     36: 
                     37: : (key) ( -- c ) \ gforth
                     38:     infile-id key-file ;
                     39: 
                     40: : (key?) ( -- flag ) \ gforth
                     41:     infile-id key?-file ;
1.2       jwilke     42: [THEN]
                     43: 
1.7       pazsan     44: undef-words
1.13      pazsan     45: 
1.7       pazsan     46: Defer type ( c-addr u -- ) \ core
1.9       crook      47:   \G If @var{u}>0, display @var{u} characters from a string starting
                     48:   \G with the character stored at @var{c-addr}.
1.13      pazsan     49: [IFDEF] write-file
                     50: : (type) 0 write-file drop ;
                     51: [ELSE]
1.9       crook      52: : (type) BEGIN dup WHILE
                     53:     >r dup c@ (emit) 1+ r> 1- REPEAT 2drop ;
1.13      pazsan     54: [THEN]
1.4       pazsan     55: 
1.7       pazsan     56: [IFDEF] (type) ' (type) IS Type [THEN]
1.2       jwilke     57: 
                     58: Defer emit ( c -- ) \ core
1.8       crook      59:   \G Display the character associated with character value c.
1.7       pazsan     60: : (emit) ( c -- ) \ gforth
                     61:     0 emit-file drop \ !! use ?DUP-IF THROW ENDIF instead of DROP ?
                     62: ;
                     63: 
                     64: [IFDEF] (emit) ' (emit) IS emit [THEN]
1.2       jwilke     65: 
1.10      crook      66: Defer key ( -- char ) \ core
                     67: \G Receive (but do not display) one character, @var{char}.
1.7       pazsan     68: 
                     69: [IFDEF] (key) ' (key) IS key [THEN]
1.5       pazsan     70: 
1.14      crook      71: Defer key? ( -- flag ) \ facility key-question
1.10      crook      72: \G Determine whether a character is available. If a character is
                     73: \G available, @var{flag} is true; the next call to @code{key} will
                     74: \G yield the character. Once @code{key?} returns true, subsequent
1.19      anton      75: \G calls to @code{key?} before calling @code{key} or @code{ekey} will
1.10      crook      76: \G also return true.
1.7       pazsan     77: 
                     78: [IFDEF] (key?) ' (key?) IS key? [THEN]
                     79: 
                     80: all-words
1.2       jwilke     81: 
                     82: : (.")     "lit count type ;
                     83: : (S")     "lit count ;
                     84: 
1.1       anton      85: \ Input                                                13feb93py
                     86: 
                     87: 07 constant #bell ( -- c ) \ gforth
                     88: 08 constant #bs ( -- c ) \ gforth
                     89: 09 constant #tab ( -- c ) \ gforth
                     90: 7F constant #del ( -- c ) \ gforth
                     91: 0D constant #cr   ( -- c ) \ gforth
                     92: \ the newline key code
                     93: 0C constant #ff ( -- c ) \ gforth
                     94: 0A constant #lf ( -- c ) \ gforth
                     95: 
1.3       jwilke     96: : bell  #bell emit [ has? os [IF] ] outfile-id flush-file drop [ [THEN] ] ;
1.14      crook      97: : cr ( -- ) \ core c-r
1.17      anton      98:     \G Output a newline (of the favourite kind of the host OS).  Note
                     99:     \G that due to the way the Forth command line interpreter inserts
                    100:     \G newlines, the preferred way to use @code{cr} is at the start
                    101:     \G of a piece of text; e.g., @code{cr ." hello, world"}.
                    102:     newline type ;
1.1       anton     103: 
1.8       crook     104: : space ( -- ) \ core
                    105:   \G Display one space.
                    106:   bl emit ;
                    107: 
1.7       pazsan    108: has? ec [IF]
1.8       crook     109: : spaces ( n -- ) \ core
                    110:   \G If n > 0, display n spaces. 
                    111:   0 max 0 ?DO space LOOP ;
1.7       pazsan    112: : backspaces  0 max 0 ?DO  #bs emit  LOOP ;
                    113: [ELSE]
1.1       anton     114: \ space spaces                                         21mar93py
                    115: decimal
                    116: Create spaces ( u -- ) \ core
1.18      anton     117:   \G Display @var{n} spaces. 
1.8       crook     118:   bl 80 times \ times from target compiler! 11may93jaw
1.1       anton     119: DOES>   ( u -- )
1.8       crook     120:   swap
                    121:   0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
1.1       anton     122: Create backspaces
1.8       crook     123:   08 80 times \ times from target compiler! 11may93jaw
1.1       anton     124: DOES>   ( u -- )
1.8       crook     125:   swap
                    126:   0 max 0 ?DO  I' I - &80 min 2dup type  +LOOP  drop ;
1.1       anton     127: hex
                    128: [THEN]
                    129: 

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