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Added section talking about different memory regions, and glossed
associated words. Glossed words associated with user input; the
manual still needs a bunch of examples for these.

    1: \ Number IO
    2: 
    3: \ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.
    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
   19: \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   20: 
   21: : pad    ( -- c-addr ) \ core-ext
   22:     \G @var{c-addr} is the address of a transient region that can be
   23:     \G used as temporary data storage. At least 84 characters of space
   24:     \G is available.
   25:     here word-pno-size + aligned ;
   26: 
   27: \ hold <# #> sign # #s                                 25jan92py
   28: 
   29: : hold    ( char -- ) \ core
   30:     \G Used within @code{<#} and @code{#>}. Append the character
   31:     \G @var{char} to the pictured numeric output string.
   32:     -1 chars holdptr +!
   33:     holdptr @ dup holdbuf u< -&17 and throw
   34:     c! ;
   35: 
   36: : <# ( -- ) \ core	less-number-sign
   37:     \G Initialise/clear the pictured numeric output string.
   38:     holdbuf-end dup holdptr ! holdend ! ;
   39: 
   40: : #>      ( xd -- addr u ) \ core	number-sign-greater
   41:     \G Complete the pictured numeric output string by
   42:     \G discarding xd and returning addr u; the address and length
   43:     \G of the formatted string. A Standard program may modify characters
   44:     \G within the string.
   45:     2drop holdptr @ holdend @ over - ;
   46: 
   47: : <<# ( -- ) \ gforth	less-less-number-sign
   48:     \G Start a hold area that ends with @code{#>>}. Can be nested in
   49:     \G each other and in @code{<#}.  Note: if you do not match up the
   50:     \G @code{<<#}s with @code{#>>}s, you will eventually run out of
   51:     \G hold area; you can reset the hold area to empty with @code{<#}.
   52:     holdend @ holdptr @ - hold
   53:     holdptr @ holdend ! ;
   54: 
   55: : #>> ( -- ) \ gforth	number-sign-greater-greater
   56:     \G Release the hold area started with @code{<<#}.
   57:     holdend @ dup holdbuf-end u>= -&11 and throw
   58:     count chars bounds holdptr ! holdend ! ;
   59: 
   60: : sign    ( n -- ) \ core
   61:     \G Used within @code{<#} and @code{#>}. If n (a @var{single} number)
   62:     \G is negative, append the display code for a minus sign to the pictured
   63:     \G numeric output string. Since the string is built up "backwards"
   64:     \G this is usually used immediately prior to @code{#>}, as shown in
   65:     \G the examples below.
   66:     0< IF  [char] - hold  THEN ;
   67: 
   68: : #       ( ud1 -- ud2 ) \ core		number-sign
   69:     \G Used within @code{<#} and @code{#>}. Add the next least-significant
   70:     \G digit to the pictured numeric output string. This is achieved by dividing ud1
   71:     \G by the number in @code{base} to leave quotient ud2 and remainder n; n
   72:     \G is converted to the appropriate display code (eg ASCII code) and appended
   73:     \G to the string. If the number has been fully converted, ud1 will be 0 and
   74:     \G @code{#} will append a "0" to the string.
   75:     base @ 2 max ud/mod rot 9 over <
   76:     IF
   77: 	[ char A char 9 - 1- ] Literal +
   78:     THEN
   79:     [char] 0 + hold ;
   80: 
   81: : #s      ( ud -- 0 0 ) \ core	number-sign-s
   82:     \G Used within @code{<#} and @code{#>}. Convert all remaining digits
   83:     \G using the same algorithm as for @code{#}. @code{#s} will convert
   84:     \G at least one digit. Therefore, if ud is 0, @code{#s} will append
   85:     \G a "0" to the pictured numeric output string.
   86:     BEGIN
   87: 	# 2dup or 0=
   88:     UNTIL ;
   89: 
   90: \ print numbers                                        07jun92py
   91: 
   92: : d.r ( d n -- ) \ double	d-dot-r
   93:     \G Display @var{d} right-aligned in a field @var{n} characters wide. If more than
   94:     \G @var{n} characters are needed to display the number, all digits are displayed.
   95:     \G If appropriate, @var{n} must include a character for a leading "-".
   96:     >r tuck  dabs  <<# #s  rot sign #>
   97:     r> over - spaces  type #>> ;
   98: 
   99: : ud.r ( ud n -- ) \ gforth	u-d-dot-r
  100:     \G Display @var{ud} right-aligned in a field @var{n} characters wide. If more than
  101:     \G @var{n} characters are needed to display the number, all digits are displayed.
  102:     >r <<# #s #> r> over - spaces type #>> ;
  103: 
  104: : .r ( n1 n2 -- ) \ core-ext	dot-r
  105:     \G Display @var{n1} right-aligned in a field @var{n2} characters wide. If more than
  106:     \G @var{n2} characters are needed to display the number, all digits are displayed.
  107:     \G If appropriate, @var{n2} must include a character for a leading "-".
  108:     >r s>d r> d.r ;
  109: 
  110: : u.r ( u n -- )  \ core-ext	u-dot-r
  111:     \G Display @var{u} right-aligned in a field @var{n} characters wide. If more than
  112:     \G @var{n} characters are needed to display the number, all digits are displayed.
  113:     0 swap ud.r ;
  114: 
  115: : d. ( d -- ) \ double	d-dot
  116:     \G Display (the signed double number) @var{d} in free-format. followed by a space.
  117:     0 d.r space ;
  118: 
  119: : ud. ( ud -- ) \ gforth	u-d-dot
  120:     \G Display (the signed double number) @var{ud} in free-format, followed by a space.
  121:     0 ud.r space ;
  122: 
  123: : . ( n -- ) \ core	dot
  124:     \G Display (the signed single number) @var{n} in free-format, followed by a space.
  125:     s>d d. ;
  126: 
  127: : u. ( u -- ) \ core	u-dot
  128:     \G Display (the unsigned single number) @var{u} in free-format, followed by a space.
  129:     0 ud. ;
  130: