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Is there a "Postscript IO file for dummies"?

Substantial part code-golfThe ones played on the Stack Overflow included ASCII digits, and codegolf.SE is formed in the same way.

This is all good and good, but I would like to add a little variety to the output and wrote my last question. Draw a reproducible crossword puzzle grid to explicitly encourage recordings in graphic format.

To show desire, I started trying to hack a link implementation in postscript. Alas, I am completely unfamiliar with the language, and I have problems with the underlying IO file. Does anyone know of a basic resource that covers the topic?

I know

  • file
  • (%stdin)
  • token
  • readstring
  • readline

but I don’t quite understand what exactly returned the last three results and how they manipulate it after you get it.

, <value> <boolean> if . ?

+2
3

File IO , . - "". , ( ), ( integertype realtype) ( , , marktype, ).

postscript:

%!
{ currentfile token pop /END-COMMENT eq {exit} if } loop
Each word here is read from the current file and converted
into a name object and compared to "/END-COMMENT".
It can have but does not need a preceeding slash.

This program produces an image of a snowman in a blizzard,
suitable for use as stationary.
END-COMMENT

showpage

: , ... .

:

(Some
multi-line
text)
pop

, .

loop.

{
} loop

.

/src (datafile) (r) file def
{
    src readline
} loop

, . !

/src (datafile) (r) file def
{
    src readline {
    }{
        exit
    } ifelse
} loop

, true - , false (no-more-data) . readline . .

/src (datafile) (r) file def
/str 80 string def
{
    src str readline {
        processline
    }{
        pop exit
    } ifelse
} loop

, (80 ) . Postscript, token (, , , , , ). get ( forall) . - search.

, , stdout .

/processline { % (line)
     ( ) { % (line) ( )
         search { % (post) ( ) (pre)
             =
         }{ % (no-match)
             =
             exit
         } ifelse
     } loop
} def

, , . , , boolean; . search - , . , . "" ( , "", ( )) ; " ".

, , ?

, cvi cvr . -, print show ; cvn .

+6

, ( ) PostScript, . , PostScript Turing , , , , PostScript .

PostScript - , . PostScript, PostScript, , , hardcoded. - , PostScript, .

, , . , , Python, , PostScript , PostScript.

. , PostScript . , "" PostScript , ; , .

This PostScript code does some calculations. Usually I will write functions in PostScript for things that I expect to do a lot, or for things that need data that only the PostScript interpreter will have, such as the width of the line in the current font, to center.

I didn’t clean anyone. Feel free to ask for clarification. NTN.

%!

% "Example"
% by (author)
% Generated 16 Apr 2005 22:19 by (program name)

% should really be eps

% unit conversions

/inch {72 mul} bind def
/cm {inch 2.54 div} bind def



%%%%%% start of adjustable parameters

% these may be fiddled with, within reason
% be careful not to change the syntax

% paper size
/page_width 8.5 inch def
/page_height 11 inch def

% page margins
/top_margin 1 inch def
/left_margin 1 inch def

% how many "cells" wide and high
/puzzle_width 9 def
/puzzle_height 9 def

% cell_size: height and width of a one-letter square, in points
/cell_size .25 inch def

% line width, in points. 1 is about maximum.
/line_width .375 def

% font and size for the numbers
/cell_font {/Helvetica 5} bind def

% top/left margin for numbers within a cell
/num_margin 1.5 def

%%%%%% end of adjustable parameters



<< /PageSize [page_width page_height] >> setpagedevice


/w_pts puzzle_width cell_size mul def
/h_pts puzzle_height cell_size mul def

/ulx left_margin def
/uly page_height top_margin sub def
/lrx ulx w_pts add def
/lry uly h_pts sub def


% draw grid

line_width setlinewidth
0 setgray

newpath ulx uly w_pts h_pts neg rectstroke

lry cell_size uly {
  newpath ulx exch moveto w_pts 0 rlineto stroke
} for

ulx cell_size lrx {
  newpath lry moveto 0 h_pts rlineto stroke
} for


% fill in black spaces

% ulx uly width height blackrect
% all in terms of cells; upper-left-most is 0,0
/blackrect
{
  << >> begin
  /h exch def /w exch def /y exch def /x exch def
  newpath
  ulx x cell_size mul add
  uly y cell_size mul sub
  w cell_size mul
  h cell_size mul neg
  rectfill
  end
} bind def

0 setgray
0 0 1 1 blackrect
3 0 2 1 blackrect
8 0 1 1 blackrect
4 1 1 1 blackrect
2 2 1 1 blackrect
6 2 1 1 blackrect
8 3 1 1 blackrect
0 4 2 1 blackrect
7 4 2 1 blackrect
0 5 1 1 blackrect
2 6 1 1 blackrect
6 6 1 1 blackrect
4 7 1 1 blackrect
0 8 1 1 blackrect
4 8 2 1 blackrect
8 8 1 1 blackrect


% draw numbers

% x y h s drawnum
% x and y in terms of cells; upper-left-most is 0,0. s is string.
% h is height of numbers. should never change, so compute once before any calls.
/drawnum
{
  << >> begin
  /s exch def /h exch def /y exch def /x exch def
  newpath
  ulx x cell_size mul add num_margin add
  uly y cell_size mul sub num_margin sub h sub
  moveto s show
  end
} bind def

0 setgray
cell_font selectfont

% compute font height
mark
newpath 0 0 moveto
(0) false charpath flattenpath pathbbox
/fh exch def
cleartomark newpath

1 0 fh (1) drawnum
2 0 fh (2) drawnum
5 0 fh (3) drawnum
6 0 fh (4) drawnum
7 0 fh (5) drawnum
0 1 fh (6) drawnum
3 1 fh (7) drawnum
5 1 fh (8) drawnum
8 1 fh (9) drawnum
0 2 fh (10) drawnum
3 2 fh (11) drawnum
4 2 fh (12) drawnum
7 2 fh (13) drawnum
0 3 fh (14) drawnum
2 3 fh (15) drawnum
6 3 fh (16) drawnum
2 4 fh (17) drawnum
1 5 fh (18) drawnum
7 5 fh (19) drawnum
8 5 fh (20) drawnum
0 6 fh (21) drawnum
3 6 fh (22) drawnum
7 6 fh (23) drawnum
0 7 fh (24) drawnum
2 7 fh (25) drawnum
5 7 fh (26) drawnum
6 7 fh (27) drawnum
1 8 fh (28) drawnum
6 8 fh (29) drawnum


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+5
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