@x Tell WEAVE to print only the changes: \def\?##1]{\hbox to 1in{\hfil##1.\ }} } @y \def\?##1]{\hbox{Changes to \hbox to 1em{\hfil##1}.\ }} } \let\maybe=\iffalse @z @x WAITS's banner: [2] @d banner=='This is TeX, Version 2.0' {printed when \TeX\ starts} @y @d banner=='This is TeX-XeT, WAITS Version 2.0' {printed when \TeX\ starts} @z @x Switches for debugging and statistics: (7) @d debug==@{ {change this to `$\\{debug}\equiv\null$' when debugging} @d gubed==@t@>@} {change this to `$\\{gubed}\equiv\null$' when debugging} @f debug==begin @f gubed==end @# @d stat==@{ {change this to `$\\{stat}\equiv\null$' when gathering usage statistics} @d tats==@t@>@} {change this to `$\\{tats}\equiv\null$' when gathering usage statistics} @f stat==begin @f tats==end @y @d debug== {change this to `$\\{debug}\equiv\null$' when debugging} @d gubed== {change this to `$\\{gubed}\equiv\null$' when debugging} @f debug==begin @f gubed==end @# @d stat== {change this to `$\\{stat}\equiv\.{@@\{}$' when not gathering usage statistics} @d tats== {change this to `$\\{tats}\equiv\.{@@\}}$' when not gathering usage statistics} @f stat==begin @f tats==end @z @x The INITEX switch: (8) @d init== {change this to `$\\{init}\equiv\.{@@\{}$' in the production version} @d tini== {change this to `$\\{tini}\equiv\.{@@\}}$' in the production version} @y [In this case, no change is made] @d init== {change this to `$\\{init}\equiv\.{@@\{}$' in the production version} @d tini== {change this to `$\\{tini}\equiv\.{@@\}}$' in the production version} @z @x Compiler directives: (9) @{@&$C-,A+,D-@} {no range check, catch arithmetic overflow, no debug overhead} @!debug @{@&$C+,D+@}@+ gubed {but turn everything on when debugging} @y @{@&$C-,A+,D-,W+,H:0@} {no range check, catch arithmetic overflow, no debug overhead, no heap} @!debug @{@&$C+,D:5,W+@}@+ gubed {but turn everything on when debugging} {the `|W+|' switch catches more syntax errors} {the `\ignorespaces|D:5|' avoids initial stop for the debugger} @z @x Compile-time constants: [11] @!mem_max=30000; {greatest index in \TeX's internal |mem| array; must be strictly less than |max_halfword|; must be equal to |mem_top| in \.{INITEX}, otherwise |>=mem_top|} @!mem_min=0; {smallest index in \TeX's internal |mem| array; must be |min_halfword| or more; must be equal to |mem_bot| in \.{INITEX}, otherwise |<=mem_bot|} @!buf_size=500; {maximum number of characters simultaneously present in current lines of open files and in control sequences between \.{\\csname} and \.{\\endcsname}; must not exceed |max_halfword|} @!error_line=72; {width of context lines on terminal error messages} @!half_error_line=42; {width of first lines of contexts in terminal error messages; should be between 30 and |error_line-15|} @!max_print_line=79; {width of longest text lines output; should be at least 60} @!stack_size=200; {maximum number of simultaneous input sources} @!max_in_open=6; {maximum number of input files and error insertions that can be going on simultaneously} @!font_max=75; {maximum internal font number; must not exceed |max_quarterword| and must be at most |font_base+256|} @!font_mem_size=20000; {number of words of |font_info| for all fonts} @!param_size=60; {maximum number of simultaneous macro parameters} @!nest_size=40; {maximum number of semantic levels simultaneously active} @!max_strings=3000; {maximum number of strings; must not exceed |max_halfword|} @!string_vacancies=8000; {the minimum number of characters that should be available for the user's control sequences and font names, after \TeX's own error messages are stored} @!pool_size=32000; {maximum number of characters in strings, including all error messages and help texts, and the names of all fonts and control sequences; must exceed |string_vacancies| by the total length of \TeX's own strings, which is currently about 23000} @!save_size=600; {space for saving values outside of current group; must be at most |max_halfword|} @!trie_size=8000; {space for hyphenation patterns; should be larger for \.{INITEX} than it is in production versions of \TeX} @!dvi_buf_size=800; {size of the output buffer; must be a multiple of 8} @!file_name_size=40; {file names shouldn't be longer than this} @!pool_name='TeXformats:TEX.POOL '; {string of length |file_name_size|; tells where the string pool appears} @.TeXformats@> @y @!mem_max=32000; {greatest index in \TeX's internal |mem| array; must be strictly less than |max_halfword|; must be equal to |mem_top| in \.{INITEX}, otherwise |>=mem_top|} @!mem_min=16000; {smallest index in \TeX's internal |mem| array; must be |min_halfword| or more; must be equal to |mem_bot| in \.{INITEX}, otherwise |<=mem_bot|} @!buf_size=500; {maximum number of characters simultaneously present in current lines of open files and in control sequences between \.{\\csname} and \.{\\endcsname}; must not exceed |max_halfword|} @!error_line=80; {width of context lines on terminal error messages} @!half_error_line=50; {width of first lines of contexts in terminal error messages; should be between 30 and |error_line-15|} @!max_print_line=80; {width of longest text lines output; should be at least 60} @!stack_size=200; {maximum number of simultaneous input sources} @!max_in_open=6; {maximum number of input files and error insertions that can be going on simultaneously} @!font_max=100; {maximum internal font number; must not exceed |max_quarterword|} @!font_mem_size=23000; {number of words of |font_info| for all fonts} @!param_size=60; {maximum number of simultaneous macro parameters} @!nest_size=40; {maximum number of semantic levels simultaneously active} @!max_strings=3500; {maximum number of strings} @!string_vacancies=8000; {the minimum number of characters that should be available for the user's control sequences and font names, after \TeX's own error messages are stored} @!pool_size=40000; {maximum number of characters in strings, including all error messages and help texts, and the names of all fonts and control sequences; must exceed |string_vacancies| by the total length of \TeX's own strings, which is currently about 22500} @!save_size=300; {space for saving values outside of current group; must be at most |max_halfword|} @!trie_size=8000; {space for hyphenation patterns; should be larger for \.{INITEX} than it is in production versions of \TeX} @!dvi_buf_size=800; {size of the output buffer; must be a multiple of 8} @!file_name_size=23; {file names shouldn't be longer than this} @!pool_name='XET.POOL[XET,DEK] '; {string of length |file_name_size|; tells where the string pool appears} @z @x TANGLE-time constants: (12) @d mem_bot=0 {smallest index in the |mem| array dumped by \.{INITEX}; must not be less than |mem_min|} @d mem_top==30000 {largest index in the |mem| array dumped by \.{INITEX}; must be substantially larger than |mem_bot| and not greater than |mem_max|} @d font_base=0 {smallest internal font number; must not be less than |min_quarterword|} @d hash_size=2100 {maximum number of control sequences; it should be at most about |(mem_max-mem_min)/10|, but 2100 is already quite generous} @d hash_prime=1777 {a prime number equal to about 85\% of |hash_size|} @d hyph_size=307 {another prime; the number of \.{\\hyphenation} exceptions} @y @d mem_bot=16000 {smallest index in the |mem| array dumped by \.{INITEX}; must not be less than |mem_min|} @d mem_top==32000 {largest index in the |mem| array dumped by \.{INITEX}; must be substantially larger than |mem_bot| and not greater than |mem_max|} @d font_base=0 {smallest internal font number; must not be less than |min_quarterword|} @d hash_size=2500 {maximum number of control sequences; it should be at most about |(mem_max-mem_min)/10|, but 2100 is already quite generous} @d hash_prime=2113 {a prime number equal to about 85\% of |hash_size|} @d hyph_size=307 {another prime; the number of \.{\\hyphenation} exceptions} @z @x System-dependent character set changes: (23) @^character set dependencies@> @^system dependencies@> @= for i:=1 to @'37 do xchr[i]:=' '; @y @^character set dependencies@> @^system dependencies@> The code shown here is intended to be used on the Stanford {\sc SAIL} system, and at other installations like CMU and ISI where essentially the same extended character set is used. The fact that {\mc SAIL} has |'}'| in the wrong place turns out to cause no difficulty in this case. @= for i:=1 to @'37 do xchr[i]:=chr(i); xchr[@'30]:=chr(@'137); xchr[@'32]:=chr(@'33); {|not_equal| sign} xchr[@'33]:=chr(@'176); @z @x Opening files: (27) @d reset_OK(#)==erstat(#)=0 @d rewrite_OK(#)==erstat(#)=0 @p function a_open_in(var f:alpha_file):boolean; {open a text file for input} begin reset(f,name_of_file,'/O'); a_open_in:=reset_OK(f); end; @# function a_open_out(var f:alpha_file):boolean; {open a text file for output} begin rewrite(f,name_of_file,'/O'); a_open_out:=rewrite_OK(f); end; @# function b_open_in(var f:byte_file):boolean; {open a binary file for input} begin reset(f,name_of_file,'/O'); b_open_in:=reset_OK(f); end; @# function b_open_out(var f:byte_file):boolean; {open a binary file for output} begin rewrite(f,name_of_file,'/O'); b_open_out:=rewrite_OK(f); end; @# function w_open_in(var f:word_file):boolean; {open a word file for input} begin reset(f,name_of_file,'/O'); w_open_in:=reset_OK(f); end; @# function w_open_out(var f:word_file):boolean; {open a word file for output} begin rewrite(f,name_of_file,'/O'); w_open_out:=rewrite_OK(f); end; @y @d reset_OK(#)==erstat(#) mod @'20000 = 0 @d rewrite_OK(#)==erstat(#) mod @'20000 = 0 @p function erstat(var f:file):integer; extern;@t/2@> @# function a_open_in(var f:alpha_file):boolean; {open a text file for input} begin reset(f,name_of_file,'/E/O/N:9'); {the \.{/E} switch distinguishes |form_feed| from |carriage_return|; the \.{/O} switch gives error control to us; and the \.{/N:9} switch specifies 9 buffers, which seems to work satisfactorily at {\mc SAIL}} a_open_in:=reset_OK(f); end; @# function a_open_out(var f:alpha_file):boolean; {open a text file for output} begin rewrite(f,name_of_file,'/O/N:2'); a_open_out:=rewrite_OK(f); end; {two buffers seems adequate for text output files} @# function b_open_in(var f:byte_file):boolean; {open a binary file for input} begin reset(f,name_of_file,'/B:8/O/N:2'); b_open_in:=reset_OK(f); end; {the \.{/B} switch is necessary to get byte packing} @# function b_open_out(var f:byte_file):boolean; {open a binary file for output} begin rewrite(f,name_of_file,'/O/N:9/P:256'); b_open_out:=rewrite_OK(f); end; {here we use |ary_out| so the \.{/B} switch isn't appropriate} {the \.{/P:256} sets file protection to `dump never'} @# function w_open_in(var f:word_file):boolean; {open a word file for input} begin reset(f,name_of_file,'/O/N:9'); w_open_in:=reset_OK(f); end; @# function w_open_out(var f:word_file):boolean; {open a word file for output} begin rewrite(f,name_of_file,'/O/N:9'); w_open_out:=rewrite_OK(f); end; @z @x New input_ln: (31) @ Input from text files is read one line at a time, using a routine called |input_ln|. This function is defined in terms of global variables called |buffer|, |first|, and |last| that will be described in detail later; for now, it suffices for us to know that |buffer| is an array of |ASCII_code| values, and that |first| and |last| are indices into this array representing the beginning and ending of a line of text. @= @!buffer:array[0..buf_size] of ASCII_code; {lines of characters being read} @!first:0..buf_size; {the first unused position in |buffer|} @!last:0..buf_size; {end of the line just input to |buffer|} @!max_buf_stack:0..buf_size; {largest index used in |buffer|} @y @ Input from text files is read one line at a time, using a routine called |input_ln|. This function is defined in terms of global variables called |buffer|, |first|, and |last| that will be described in detail later; for now, it suffices for us to know that |buffer| is an array of |ASCII_code| values, and that |first| and |last| are indices into this array representing the beginning and ending of a line of text. We will read the lines first into an auxiliary buffer, in order to save the running time of procedure-call overhead. This uses a nice feature of \ph\ that Knuth chose not to mention in \TeX82. @^Knuth, Donald Ervin@> At {\mc SAIL} we want to recognize page marks (indicated by |form_feed| characters), and keep track of the current page number. @d form_feed=@'14 {ASCII code used at end of a page} @= @!buffer:array[0..buf_size] of ASCII_code; {lines of characters being read} @!first:0..buf_size; {the first unused position in |buffer|} @!last:0..buf_size; {end of the line just input to |buffer|} @!max_buf_stack:0..buf_size; {largest index used in |buffer|} @!aux_buf:array[0..70] of text_char; {where the characters go first} @^system dependencies@> @z @x @p function input_ln(var f:alpha_file;@!bypass_eoln:boolean):boolean; {inputs the next line or returns |false|} var last_nonblank:0..buf_size; {|last| with trailing blanks removed} begin if bypass_eoln then if not eof(f) then get(f); {input the first character of the line into |f^|} last:=first; {cf.\ Matthew 19\thinspace:\thinspace30} if eof(f) then input_ln:=false else begin last_nonblank:=first; while not eoln(f) do begin if last>=max_buf_stack then begin max_buf_stack:=last+1; if max_buf_stack=buf_size then overflow("buffer size",buf_size); @:TeX capacity exceeded buffer size}{\quad buffer size@> end; buffer[last]:=xord[f^]; get(f); incr(last); if buffer[last-1]<>" " then last_nonblank:=last; end; last:=last_nonblank; input_ln:=true; end; end; @y @p function input_ln(var f:alpha_file;@!bypass_eoln:boolean):boolean; {inputs the next line or returns |false|} label 1,done; var n: integer; @!k,@!m: 0..buf_size; {indices into |buffer|} begin if bypass_eoln then {input the first character of the line into |f^|} begin if not eof(f) then get(f); if not eof(f) then if f^=chr(@'12) then get(f); {skip past a |line_feed|} end; last:=first; if eof(f) then input_ln:=false else begin read(f,aux_buf:n); if buffer[first]=form_feed then {previous line was end-of-page} begin incr(page); line:=1; {adjust line and page numbers} end; 1: if last+n>max_buf_stack then if last+n>=buf_size then begin max_buf_stack:=buf_size; overflow("buffer size",buf_size); @:TeX capacity exceeded buffer size}{\quad buffer size@> end else max_buf_stack:=last+n; if n>0 then begin m:=last; if n=72 then last:=m+71@+else last:=m+n; for k:=m to last-1 do buffer[k]:=xord[aux_buf[k-m]]; if n=72 then {there's more on this line} begin read(f,aux_buf:n); goto 1; end; end else if f^=chr(form_feed) then {end of page} begin aux_buf[0]:=f^; n:=1; goto 1; end; loop@+ begin if last=first then goto done; if buffer[last-1]<>" " then goto done; decr(last); end; done: input_ln:=true; end; end; @^system dependencies@> @z @x Terminal I/O: (32) is considered an output file the file variable is |term_out|. @^system dependencies@> @= @!term_in:alpha_file; {the terminal as an input file} @!term_out:alpha_file; {the terminal as an output file} @ Here is how to open the terminal files in \ph. The `\.{/I}' switch suppresses the first |get|. @^system dependencies@> @d t_open_in==reset(term_in,'TTY:','/O/I') {open the terminal for text input} @d t_open_out==rewrite(term_out,'TTY:','/O') {open the terminal for text output} @y is considered an output file the file variable is |term_out|. On WAITS, this point is moot, since we use the built-in |TTY| file. @^system dependencies@> @d term_in==TTY {the terminal as an input file} @d term_out==TTY {the terminal as an output file} @ Here is how to open the terminal files on WAITS: we don't do anything, since |TTY| is always open. Note that |eoln(term_in)| is initially |true|. @^system dependencies@> @d t_open_in==do_nothing {open the terminal for text input} @d t_open_out==do_nothing {open the terminal for text output} @z @x Special terminal controls: (34) @d clear_terminal == break_in(term_in,true) {clear the terminal input buffer} @d wake_up_terminal == do_nothing {cancel the user's cancellation of output} @y @d clear_terminal == break_in(term_in,true) {clear the terminal input buffer} @d wake_up_terminal == begin if inskp0 then end {cancel the user's cancellation of output} @= function inskp0:boolean; extern; @z @x Initializing the terminal: (37) @ The following program does the required initialization without retrieving a possible command line. It should be clear how to modify this routine to deal with command lines, if the system permits them. @^system dependencies@> @p function init_terminal:boolean; {gets the terminal input started} label exit; begin t_open_in; loop@+begin wake_up_terminal; write(term_out,'**'); update_terminal; @.**@> if not input_ln(term_in,true) then {this shouldn't happen} begin write_ln(term_out); write(term_out,'! End of file on the terminal... why?'); @.End of file on the terminal@> init_terminal:=false; return; end; loc:=first; while (loc @d pto_chr(#)==ptwr1w(0,ord(#)) {put a character in the line editor} @p procedure esci(var x:integer); extern; @t\2@>@; {increments |x| each time the user types escape-I or break-I; the program can change |x| whenever it wants to, but |x| had better be a global variable} @# function rescan:boolean; extern; @t\2@>@; {puts the command line into the terminal buffer, or returns |false| if there was no command line} @# function tmp_in(f:string;var s:string):integer; extern; @t\2@>@; {reads \.{TMPCOR} file |f| into |s|, and returns its length (|<=0| means error)} @# function cclsw: boolean; extern; @t\2@>@; {was program started with \.{RUN} offset of 1 (i.e., from \.{SNAIL})?} @# procedure ptwr1w(pty,c:integer); extern; @t\2@>@; {simulates typing of a character on a \.{PTY}} @# function init_terminal:boolean; {gets the terminal files started} label exit; var l:integer; {length returned by |tmp_in|} @!line_found:boolean; {have we scanned a line?} @!tmp_cor_buf:packed array[0..100] of char; {where |tmp_in| puts things} begin t_open_in; esci(interrupt); last:=first; if cclsw then {started by \.{TEX} monitor command} begin l:=tmp_in('TEX',tmp_cor_buf); loc:=1; while (loc':=') do incr(loc); incr(loc); while loc' ' then begin buffer[last]:=xord[tmp_cor_buf[loc]]; incr(last); end; incr(loc); end; end else @!debug if false then@;@+gubed@;@/ if rescan then begin read_ln(term_in); {get first character into |term_in^|} while (not eoln(term_in))and(term_in^<>';') do get(term_in); if term_in^=';' then begin get(term_in); while not eoln(term_in) do begin buffer[last]:=xord[term_in^]; incr(last); get(term_in); end; end; end; line_found:=(last>first); loop@+ begin loc:=first; while (loc buffer[first]:=0; {|input_ln| may look at |buffer[first]|} if not input_ln(term_in,true) then {this shouldn't happen} begin write_ln(term_out); write(term_out,'! End of file on the terminal... why?'); @.End of file on the terminal@> init_terminal:=false; return; end; line_found:=true; end; exit:end; @^system dependencies@> @z @x Making special characters printable: (49) @= (k<" ")or(k>"~") @y @= (k=@'177)or(k in [0,@'11..@'15,@'33]) @z @x Terminal input: (71) begin update_terminal; {Now the user sees the prompt for sure} @y begin update_terminal; {Now the user sees the prompt for sure} buffer[first]:=0; {makes sure |input_ln| doesn't find a |form_feed|} @z @x The `E' option: (84) line ready to be edited. But such an extension requires some system wizardry, so the present implementation simply types out what file should be edited and the relevant line number. @y line ready to be edited. The present implementation does this by loading the line editor with the appropriate call to the editor. We treat `\.T' the same as `\.E', because other programs on this system invoke the editor when the user says `\.T'. @z @x "E": if base_ptr>0 then begin print_nl("You want to edit file "); @.You want to edit file x@> print(input_stack[base_ptr].name_field); print(" at line "); print_int(line); interaction:=scroll_mode; jump_out; end; @y "E","T": if base_ptr>0 then begin selector:=new_string; pool_ptr:=str_start[str_ptr]; print("et "); print(input_stack[base_ptr].name_field); print_char("/"); print_int(page); print("p/"); print_int(line); print_char("l"); print_char(carriage_return); if str_ptr@^system dependencies@> @d qi(#)==#+min_quarterword {to put an |eight_bits| item into a quarterword} @d qo(#)==#-min_quarterword {to take an |eight_bits| item out of a quarterword} @d hi(#)==#+min_halfword {to put a sixteen-bit item into a halfword} @d ho(#)==#-min_halfword {to take a sixteen-bit item from a halfword} @y The inner loop of \TeX\ will run faster with respect to compilers that don't optimize expressions like `|x+0|' and `|x-0|', if these macros are simplified in the obvious way when |min_quarterword=0|. So they have been simplified here in the obvious way. @^inner loop@>@^system dependencies@> @d qi(#)==# {to put an |eight_bits| item into a quarterword} @d qo(#)==# {to take an |eight_bits| item from a quarterword} @d hi(#)==# {to put a sixteen-bit item into a halfword} @d ho(#)==# {to take a sixteen-bit item from a halfword} @z @x Kludge to get around Pascal bug (with large array lower bounds) (116) @!mem : array[mem_min..mem_max] of memory_word; {the big dynamic storage area} @y @z @x make room for a new creation procedure [161] \TeX's other algorithms intact. @^system dependencies@> @y \TeX's other algorithms intact. @^system dependencies@> @p@ @z @x New command code [208-209] @d max_non_prefixed_command=69 {largest command code that can't be \.{\\global}} @ The next codes are special; they all relate to mode-independent assignment of values to \TeX's internal registers or tables. Codes that are |max_internal| or less represent internal quantities that might be expanded by `\.{\\the}'. @d toks_register=70 {token list register ( \.{\\toks} )} @d assign_toks=71 {special token list ( \.{\\output}, \.{\\everypar}, etc.~)} @d assign_int=72 {user-defined integer ( \.{\\tolerance}, \.{\\day}, etc.~)} @d assign_dimen=73 {user-defined length ( \.{\\hsize}, etc.~)} @d assign_glue=74 {user-defined glue ( \.{\\baselineskip}, etc.~)} @d assign_mu_glue=75 {user-defined muglue ( \.{\\thinmuskip}, etc.~)} @d assign_font_dimen=76 {user-defined font dimension ( \.{\\fontdimen} )} @d assign_font_int=77 {user-defined font integer ( \.{\\hyphenchar}, \.{\\skewchar} )} @d set_aux=78 {specify state info ( \.{\\spacefactor}, \.{\\prevdepth} )} @d set_prev_graf=79 {specify state info ( \.{\\prevgraf} )} @d set_page_dimen=80 {specify state info ( \.{\\pagegoal}, etc.~)} @d set_page_int=81 {specify state info ( \.{\\deadcycles}, \.{\\insertpenalties} )} @d set_box_dimen=82 {change dimension of box ( \.{\\wd}, \.{\\ht}, \.{\\dp} )} @d set_shape=83 {specify fancy paragraph shape ( \.{\\parshape} )} @d def_code=84 {define a character code ( \.{\\catcode}, etc.~)} @d def_family=85 {declare math fonts ( \.{\\textfont}, etc.~)} @d set_font=86 {set current font ( font identifiers )} @d def_font=87 {define a font file ( \.{\\font} )} @d register=88 {internal register ( \.{\\count}, \.{\\dimen}, etc.~)} @d max_internal=88 {the largest code that can follow \.{\\the}} @d advance=89 {advance a register or parameter ( \.{\\advance} )} @d multiply=90 {multiply a register or parameter ( \.{\\multiply} )} @d divide=91 {divide a register or parameter ( \.{\\divide} )} @d prefix=92 {qualify a definition ( \.{\\global}, \.{\\long}, \.{\\outer} )} @d let=93 {assign a command code ( \.{\\let}, \.{\\futurelet} )} @d shorthand_def=94 {code definition ( \.{\\chardef}, \.{\\countdef}, etc.~)} @d read_to_cs=95 {read into a control sequence ( \.{\\read} )} @d def=96 {macro definition ( \.{\\def}, \.{\\gdef}, \.{\\xdef}, \.{\\edef} )} @d set_box=97 {set a box ( \.{\\setbox} )} @d hyph_data=98 {hyphenation data ( \.{\\hyphenation}, \.{\\patterns} )} @d set_interaction=99 {define level of interaction ( \.{\\batchmode}, etc.~)} @d max_command=99 {the largest command code seen at |big_switch|} @y @d LR=70 {text direction ( \.{\\beginL}, \.{\\beginR}, \.{\\endL}, \.{\\endR} )} @d max_non_prefixed_command=70 {largest command code that can't be \.{\\global}} @ The next codes are special; they all relate to mode-independent assignment of values to \TeX's internal registers or tables. Codes that are |max_internal| or less represent internal quantities that might be expanded by `\.{\\the}'. @d toks_register=71 {token list register ( \.{\\toks} )} @d assign_toks=72 {special token list ( \.{\\output}, \.{\\everypar}, etc.~)} @d assign_int=73 {user-defined integer ( \.{\\tolerance}, \.{\\day}, etc.~)} @d assign_dimen=74 {user-defined length ( \.{\\hsize}, etc.~)} @d assign_glue=75 {user-defined glue ( \.{\\baselineskip}, etc.~)} @d assign_mu_glue=76 {user-defined muglue ( \.{\\thinmuskip}, etc.~)} @d assign_font_dimen=77 {user-defined font dimension ( \.{\\fontdimen} )} @d assign_font_int=78 {user-defined font integer ( \.{\\hyphenchar}, \.{\\skewchar} )} @d set_aux=79 {specify state info ( \.{\\spacefactor}, \.{\\prevdepth} )} @d set_prev_graf=80 {specify state info ( \.{\\prevgraf} )} @d set_page_dimen=81 {specify state info ( \.{\\pagegoal}, etc.~)} @d set_page_int=82 {specify state info ( \.{\\deadcycles}, \.{\\insertpenalties} )} @d set_box_dimen=83 {change dimension of box ( \.{\\wd}, \.{\\ht}, \.{\\dp} )} @d set_shape=84 {specify fancy paragraph shape ( \.{\\parshape} )} @d def_code=85 {define a character code ( \.{\\catcode}, etc.~)} @d def_family=86 {declare math fonts ( \.{\\textfont}, etc.~)} @d set_font=87 {set current font ( font identifiers )} @d def_font=88 {define a font file ( \.{\\font} )} @d register=89 {internal register ( \.{\\count}, \.{\\dimen}, etc.~)} @d max_internal=89 {the largest code that can follow \.{\\the}} @d advance=90 {advance a register or parameter ( \.{\\advance} )} @d multiply=91 {multiply a register or parameter ( \.{\\multiply} )} @d divide=92 {divide a register or parameter ( \.{\\divide} )} @d prefix=93 {qualify a definition ( \.{\\global}, \.{\\long}, \.{\\outer} )} @d let=94 {assign a command code ( \.{\\let}, \.{\\futurelet} )} @d shorthand_def=95 {code definition ( \.{\\chardef}, \.{\\countdef}, etc.~)} @d read_to_cs=96 {read into a control sequence ( \.{\\read} )} @d def=97 {macro definition ( \.{\\def}, \.{\\gdef}, \.{\\xdef}, \.{\\edef} )} @d set_box=98 {set a box ( \.{\\setbox} )} @d hyph_data=99 {hyphenation data ( \.{\\hyphenation}, \.{\\patterns} )} @d set_interaction=100 {define level of interaction ( \.{\\batchmode}, etc.~)} @d max_command=100 {the largest command code seen at |big_switch|} @z @x Special form_feed initialization: (232) cat_code("\"):=escape; cat_code("%"):=comment; @y cat_code("\"):=escape; cat_code("%"):=comment; cat_code(form_feed):=car_ret; @z @x Date and time: (241) Since standard \PASCAL\ cannot provide such information, something special is needed. The program here simply specifies July 4, 1776, at noon; but users probably want a better approximation to the truth. @p procedure fix_date_and_time; begin time:=12*60; {minutes since midnight} day:=4; {fourth day of the month} month:=7; {seventh month of the year} year:=1776; {Anno Domini} end; @y It uses a {\mc WAITS} monitor call that puts the date in the left 18 bits and the time in the right 18 bits. @p procedure fix_date_and_time; var t:integer; {accumulator} date:integer; {raw date} g:boolean; {garbage} begin call_i(@'400101,,t,t,g); {that's \.{ACCTIM}} date:=t div @'1000000; time:=(t mod @'1000000) div 60; day:=(date mod 31)+1; month:=((date div 31) mod 12)+1; year:=(date div (31*12))+1964; end; @z @x Page number maintenance: (304) If more information about the input state is needed, it can be included in small arrays like those shown here. For example, the current page or segment number in the input file might be put into a variable |@!page|, maintained for enclosing levels in `\ignorespaces|@!page_stack:array[1..max_in_open] of integer|\unskip' by analogy with |line_stack|. @y Similarly, we maintain a global variable |page| and a corresponding |page_stack|. @z @x @!line_stack : array[1..max_in_open] of integer; @y @!line_stack : array[1..max_in_open] of integer; @!page : integer; {current page number in the current source file} @!page_stack : array[1..max_in_open] of integer; @z @x Printing the page number: (313) else begin print_nl("l."); print_int(line); @y else begin if page>1 then begin print_nl("p."); print_int(page); print(",l."); end else print_nl("l."); print_int(line); @z @x More page number maintenance: (328) or |limit| or |line|. @y or |limit| or |line| or |page|. @z @x line_stack[index]:=line; start:=first; state:=mid_line; @y line_stack[index]:=line; start:=first; state:=mid_line; page_stack[index]:=page; @z @x begin first:=start; line:=line_stack[index]; @y begin first:=start; page:=page_stack[index]; line:=line_stack[index]; @z @x More page number printing: (336) print("; all text was ignored after line "); print_int(skip_line); @y print("; all text was ignored after line "); print_int(skip_line); if skip_page>1 then begin print(", p."); print_int(skip_page); end; @z @x Pausing on input: (363) @ If the user has set the |pausing| parameter to some positive value, and if nonstop mode has not been selected, each line of input is displayed on the terminal and the transcript file, followed by `\.{=>}'. \TeX\ waits for a response. If the response is simply |carriage_return|, the line is accepted as it stands, otherwise the line typed is used instead of the line in the file. @p procedure firm_up_the_line; var k:0..buf_size; {an index into |buffer|} begin limit:=last; if pausing>0 then if interaction>nonstop_mode then begin wake_up_terminal; print_ln; if start"); {wait for user response} @.=>@> if last>first then begin for k:=first to last-1 do {move line down in buffer} buffer[k+start-first]:=buffer[k]; limit:=start+last-first; end; end; end; @y @ If the user} @d wake_up_terminal == do_nothing {cancel the user's cancellation of output} @y @d clear_terminal == break_in(term_in,true) {clear the terminal input buffer} @d wake_up_terminal == begin if inskp0 then end {cancel the user's cancellation of output} @= function inskp0:boolean; extern; @z @x Initializing the terminal: (37) @ The following program does the required initialization without retrieving a possible command line. It should be clear how to modify this routine to deal with command lines, if the system permits them. @^system dependencies@> @p function init_terminal:boolean; {gets the terminal input started} label exit; begin t_open_in; loop@+begin wake_up_terminal; write(term_out,'**'); update_terminal; @.**@> if not input_ln(term_in,true) then {this shouldn't happen} begin write_ln(term_out); write(term_out,'! End of file on the terminal... why?'); @.End of file on the terminal@> init_terminal:=false; return; end; loc:=first; while (loc @d pto_chr(#)==ptwr1w(0,ord(#)) {put a character in the line editor} @p procedure esci(var x:integer); extern; @t\2@>@; {increments |x| each time the user types escape-I or break-I; the program can change |x| whenever it wants to, but |x| had better be a global variable} @# function rescan:boolean; extern; @t\2@>@; {puts the command line into the terminal buffer, or returns |false| if there was no command line} @# function tmp_in(f:string;var s:string):integer; extern; @t\2@>@; {reads \.{TMPCOR} file |f| into |s|, and returns its length (|<=0| means error)} @# function cclsw: boolean; extern; @t\2@>@; {was program started with \.{RUN} offset of 1 (i.e., from \.{SNAIL})?} @# procedure ptwr1w(pty,c:integer); extern; @t\2@>@; {simulates typing of a character on a \.{PTY}} @# function init_terminal:boolean; {gets the terminal files started} label exit; var l:integer; {length returned by |tmp_in|} @!line_found:boolean; {have we scanned a line?} @!tmp_cor_buf:packed array[0..100] of char; {where |tmp_in| puts things} begin t_open_in; esci(interrupt); last:=first; if cclsw then {started by \.{TEX} monitor command} begin l:=tmp_in('TEX',tmp_cor_buf); loc:=1; while (loc':=') do incr(loc); incr(loc); while loc' ' then begin buffer[last]:=xord[tmp_cor_buf[loc]]; incr(last); end; incr(loc); end; end else @!debug if false then@;@+gubed@;@/ if rescan then begin read_ln(term_in); {get first character into |term_in^|} while (not eoln(term_in))and(term_in^<>';') do get(term_in); if term_in^=';' then begin get(term_in); while not eoln(term_in) do begin buffer[last]:=xord[term_in^]; incr(last); get(term_in); end; end; end; line_found:=(last>first); loop@+ begin loc:=first; while (loc buffer[first]:=0; {|input_ln| may look at |buffer[first]|} if not input_ln(term_in,true) then {this shouldn't happen} begin write_ln(term_out); write(term_out,'! End of file on the terminal... why?'); @.End of file on the terminal@> init_terminal:=false; return; end; line_found:=true; end; exit:end; @^system dependencies@> @z @x Making special characters printable: (49) @= (k<" ")or(k>"~") @y @= (k=@'177)or(k in [0,@'11..@'15,@'33]) @z @x Terminal input: (71) begin update_terminal; {Now the user sees the prompt for sure} @y begin update_terminal; {Now the user sees the prompt for sure} buffer[first]:=0; {makes sure |input_ln| doesn't find a |form_feed|} @z @x The `E' option: (84) line ready to be edited. But such an extension requires some system wizardry, so the present implementation simply types out what file should be edited and the relevant line number. @y line ready to be edited. The present implementation does this by loading the line editor with the appropriate call to the editor. We treat `\.T' the same as `\.E', because other programs on this system invoke the editor when the user says `\.T'. @z @x "E": if base_ptr>0 then begin print_nl("You want to edit file "); @.You want to edit file x@> print(input_stack[base_ptr].name_field); print(" at line "); print_int(line); interaction:=scroll_mode; jump_out; end; @y "E","T": if base_ptr>0 then begin selector:=new_string; pool_ptr:=str_start[str_ptr]; print("et "); print(input_stack[base_ptr].name_field); print_char("/"); print_int(page); print("p/"); print_int(line); print_char("l"); print_char(carriage_return); if str_ptr@^system dependencies@> @d qi(#)==#+min_quarterword {to put an |eight_bits| item into a quarterword} @d qo(#)==#-min_quarterword {to take an |eight_bits| item out of a quarterword} @d hi(#)==#+min_halfword {to put a sixteen-bit item into a halfword} @d ho(#)==#-min_halfword {to take a sixteen-bit item from a halfword} @y The inner loop of \TeX\ will run faster with respect to compilers that don't optimize expressions like `|x+0|' and `|x-0|', if these macros are simplified in the obvious way when |min_quarterword=0|. So they have been simplified here in the obvious way. @^inner loop@>@^system dependencies@> @d qi(#)==# {to put an |eight_bits| item into a quarterword} @d qo(#)==# {to take an |eight_bits| item from a quarterword} @d hi(#)==# {to put a sixteen-bit item into a halfword} @d ho(#)==# {to take a sixteen-bit item from a halfword} @z @x Kludge to get around Pascal bug (with large array lower bounds) (116) @!mem : array[mem_min..mem_max] of memory_word; {the big dynamic storage area} @y @z @x make room for a new creation procedure [161] \TeX's other algorithms intact. @^system dependencies@> @y \TeX's other algorithms intact. @^system dependencies@> @p@ @z @x New command code [208-209] @d max_non_prefixed_command=69 {largest command code that can't be \.{\\global}} @ The next codes are special; they all relate to mode-independent assignment of values to \TeX's internal registers or tables. Codes that are |max_internal| or less represent internal quantities that might be expanded by `\.{\\the}'. @d toks_register=70 {token list register ( \.{\\toks} )} @d assign_toks=71 {special token list ( \.{\\output}, \.{\\everypar}, etc.~)} @d assign_int=72 {user-defined integer ( \.{\\tolerance}, \.{\\day}, etc.~)} @d assign_dimen=73 {user-defined length ( \.{\\hsize}, etc.~)} @d assign_glue=74 {user-defined glue ( \.{\\baselineskip}, etc.~)} @d assign_mu_glue=75 {user-defined muglue ( \.{\\thinmuskip}, etc.~)} @d assign_font_dimen=76 {user-defined font dimension ( \.{\\fontdimen} )} @d assign_font_int=77 {user-defined font integer ( \.{\\hyphenchar}, \.{\\skewchar} )} @d set_aux=78 {specify state info ( \.{\\spacefactor}, \.{\\prevdepth} )} @d set_prev_graf=79 {specify state info ( \.{\\prevgraf} )} @d set_page_dimen=80 {specify state info ( \.{\\pagegoal}, etc.~)} @d set_page_int=81 {specify state info ( \.{\\deadcycles}, \.{\\insertpenalties} )} @d set_box_dimen=82 {change dimension of box ( \.{\\wd}, \.{\\ht}, \.{\\dp} )} @d set_shape=83 {specify fancy paragraph shape ( \.{\\parshape} )} @d def_code=84 {define a character code ( \.{\\catcode}, etc.~)} @d def_family=85 {declare math fonts ( \.{\\textfont}, etc.~)} @d set_font=86 {set current font ( font identifiers )} @d def_font=87 {define a font file ( \.{\\font} )} @d register=88 {internal register ( \.{\\count}, \.{\\dimen}, etc.~)} @d max_internal=88 {the largest code that can follow \.{\\the}} @d advance=89 {advance a register or parameter ( \.{\\advance} )} @d multiply=90 {multiply a register or parameter ( \.{\\multiply} )} @d divide=91 {divide a register or parameter ( \.{\\divide} )} @d prefix=92 {qualify a definition ( \.{\\global}, \.{\\long}, \.{\\outer} )} @d let=93 {assign a command code ( \.{\\let}, \.{\\futurelet} )} @d shorthand_def=94 {code definition ( \.{\\chardef}, \.{\\countdef}, etc.~)} @d read_to_cs=95 {read into a control sequence ( \.{\\read} )} @d def=96 {macro definition ( \.{\\def}, \.{\\gdef}, \.{\\xdef}, \.{\\edef} )} @d set_box=97 {set a box ( \.{\\setbox} )} @d hyph_data=98 {hyphenation data ( \.{\\hyphenation}, \.{\\patterns} )} @d set_interaction=99 {define level of interaction ( \.{\\batchmode}, etc.~)} @d max_command=99 {the largest command code seen at |big_switch|} @y @d LR=70 {text direction ( \.{\\beginL}, \.{\\beginR}, \.{\\endL}, \.{\\endR} )} @d max_non_prefixed_command=70 {largest command code that can't be \.{\\global}} @ The next codes are special; they all relate to mode-independent assignment of values to \TeX's internal registers or tables. Codes that are |max_internal| or less represent internal quantities that might be expanded by `\.{\\the}'. @d toks_register=71 {token list register ( \.{\\toks} )} @d assign_toks=72 {special token list ( \.{\\output}, \.{\\everypar}, etc.~)} @d assign_int=73 {user-defined integer ( \.{\\tolerance}, \.{\\day}, etc.~)} @d assign_dimen=74 {user-defined length ( \.{\\hsize}, etc.~)} @d assign_glue=75 {user-defined glue ( \.{\\baselineskip}, etc.~)} @d assign_mu_glue=76 {user-defined muglue ( \.{\\thinmuskip}, etc.~)} @d assign_font_dimen=77 {user-defined font dimension ( \.{\\fontdimen} )} @d assign_font_int=78 {user-defined font integer ( \.{\\hyphenchar}, \.{\\skewchar} )} @d set_aux=79 {specify state info ( \.{\\spacefactor}, \.{\\prevdepth} )} @d set_prev_graf=80 {specify state info ( \.{\\prevgraf} )} @d set_page_dimen=81 {specify state info ( \.{\\pagegoal}, etc.~)} @d set_page_int=82 {specify state info ( \.{\\deadcycles}, \.{\\insertpenalties} )} @d set_box_dimen=83 {change dimension of box ( \.{\\wd}, \.{\\ht}, \.{\\dp} )} @d set_shape=84 {specify fancy paragraph shape ( \.{\\parshape} )} @d def_code=85 {define a character code ( \.{\\catcode}, etc.~)} @d def_family=86 {declare math fonts ( \.{\\textfont}, etc.~)} @d set_font=87 {set current font ( font identifiers )} @d def_font=88 {define a font file ( \.{\\font} )} @d register=89 {internal register ( \.{\\count}, \.{\\dimen}, etc.~)} @d max_internal=89 {the largest code that can follow \.{\\the}} @d advance=90 {advance a register or parameter ( \.{\\advance} )} @d multiply=91 {multiply a register or parameter ( \.{\\multiply} )} @d divide=92 {divide a register or parameter ( \.{\\divide} )} @d prefix=93 {qualify a definition ( \.{\\global}, \.{\\long}, \.{\\outer} )} @d let=94 {assign a command code ( \.{\\let}, \.{\\futurelet} )} @d shorthand_def=95 {code definition ( \.{\\chardef}, \.{\\countdef}, etc.~)} @d read_to_cs=96 {read into a control sequence ( \.{\\read} )} @d def=97 {macro definition ( \.{\\def}, \.{\\gdef}, \.{\\xdef}, \.{\\edef} )} @d set_box=98 {set a box ( \.{\\setbox} )} @d hyph_data=99 {hyphenation data ( \.{\\hyphenation}, \.{\\patterns} )} @d set_interaction=100 {define level of interaction ( \.{\\batchmode}, etc.~)} @d max_command=100 {the largest command code seen at |big_switch|} @z @x Special form_feed initialization: (232) cat_code("\"):=escape; cat_code("%"):=comment; @y cat_code("\"):=escape; cat_code("%"):=comment; cat_code(form_feed):=car_ret; @z @x Date and time: (241) Since standard \PASCAL\ cannot provide such information, something special is needed. The program here simply specifies July 4, 1776, at noon; but users probably want a better approximation to the truth. @p procedure fix_date_and_time; begin time:=12*60; {minutes since midnight} day:=4; {fourth day of the month} month:=7; {seventh month of the year} year:=1776; {Anno Domini} end; @y It uses a {\mc WAITS} monitor call that puts the date in the left 18 bits and the time in the right 18 bits. @p procedure fix_date_and_time; var t:integer; {accumulator} date:integer; {raw date} g:boolean; {garbage} begin call_i(@'400101,,t,t,g); {that's \.{ACCTIM}} date:=t div @'1000000; time:=(t mod @'1000000) div 60; day:=(date mod 31)+1; month:=((date div 31) mod 12)+1; year:=(date div (31*12))+1964; end; @z @x Page number maintenance: (304) If more information about the input state is needed, it can be included in small arrays like those shown here. For example, the current page or segment number in the input file might be put into a variable |@!page|, maintained for enclosing levels in `\ignorespaces|@!page_stack:array[1..max_in_open] of integer|\unskip' by analogy with |line_stack|. @y Similarly, we maintain a global variable |page| and a corresponding |page_stack|. @z @x @!line_stack : array[1..max_in_open] of integer; @y @!line_stack : array[1..max_in_open] of integer; @!page : integer; {current page number in the current source file} @!page_stack : array[1..max_in_open] of integer; @z @x Printing the page number: (313) else begin print_nl("l."); print_int(line); @y else begin if page>1 then begin print_nl("p."); print_int(page); print(",l."); end else print_nl("l."); print_int(line); @z @x More page number maintenance: (328) or |limit| or |line|. @y or |limit| or |line| or |page|. @z @x line_stack[index]:=line; start:=first; state:=mid_line; @y line_stack[index]:=line; start:=first; state:=mid_line; page_stack[index]:=page; @z @x begin first:=start; line:=line_stack[index]; @y begin first:=start; page:=page_stack[index]; line:=line_stack[index]; @z @x More page number printing: (336) print("; all text was ignored after line "); print_int(skip_line); @y print("; all text was ignored after line "); print_int(skip_line); if skip_page>1 then begin print(", p."); print_int(skip_page); end; @z @x Pausing on input: (363) @ If the user has set the |pausing| parameter to some positive value, and if nonstop mode has not been selected, each line of input is displayed on the terminal and the transcript file, followed by `\.{=>}'. \TeX\ waits for a response. If the response is simply |carriage_return|, the line is accepted as it stands, otherwise the line typed is used instead of the line in the file. @p procedure firm_up_the_line; var k:0..buf_size; {an index into |buffer|} begin limit:=last; if pausing>0 then if interaction>nonstop_mode then begin wake_up_terminal; print_ln; if start"); {wait for user response} @.=>@> if last>first then begin for k:=first to last-1 do {move line down in buffer} buffer[k+start-first]:=buffer[k]; limit:=start+last-first; end; end; end; @y @ If the user has set the |pausing| parameter to some positive value, and if nonstop mode has not been selected, each line of input is displayed in the transcript file, followed by `\.{=>}', and also put into the user's line-editor buffer. \TeX\ waits for the line to be edited, and the next line received is used instead of the line in the file. @p procedure firm_up_the_line; var k:0..buf_size; {an index into |buffer|} begin limit:=last; if pausing>0 then if interaction>nonstop_mode then if buffer[start]<>form_feed then begin wake_up_terminal; print_ln; if start=limit then {empty line will be made nonempty so that it's visible} begin buffer[start]:=" "; incr(limit); end; decr(selector); {inhibit terminal output temporarily} for k:=start to limit-1 do begin print_char(buffer[k]); pto_chr(xchr[buffer[k]]); end; print("=>"); first:=start; if not input_ln(term_in,true) then fatal_error("End of file on the terminal!"); @.End of file on the terminal@> if last>first then for k:=first to last-1 do print_char(buffer[k]); limit:=last; print_ln; incr(selector); end; end; @z @x Reading the first line of a file: (485) @ The first line of a file must be treated specially, since |input_ln| must be told not to start with |get|. @^system dependencies@> @= if input_ln(read_file[m],false) then read_open[m]:=normal else begin a_close(read_file[m]); read_open[m]:=closed; end @y @ The first line of a file must be treated specially, since |input_ln| must be told not to |get|. Furthermore we want to omit the optional file directory page present at {\mc SAIL}. @^system dependencies@> @= if not input_ln(read_file[m],false) then begin a_close(read_file[m]); read_open[m]:=closed; end else begin if(last-start=29)and(buffer[start]="C")and(buffer[start+8]=@'26) then begin while (read_file[m]^<>chr(form_feed))and(not eof(read_file[m])) do begin read_ln(read_file[m]); read(read_file[m],aux_buf:temp_ptr); end; {skip the directory} buffer[start]:=form_feed; last:=start+1; end; read_open[m]:=normal; end @z @x Still more page number maintenance: (493) where skipping began, for use in error messages. @= @!skip_line:integer; {skipping began here} @y where skipping began, for use in error messages. Also the page number. @= @!skip_line,@!skip_page:integer; {skipping began here} @z @x skip_line:=line; @y skip_line:=line; skip_page:=page; @z @x Parsing file names: (513) @ The file names we shall deal with for illustrative purposes have the following structure: If the name contains `\.>' or `\.:', the file area consists of all characters up to and including the final such character; otherwise the file area is null. If the remaining file name contains `\..', the file extension consists of all such characters from the first remaining `\..' to the end, otherwise the file extension is null. @^system dependencies@> We can scan such file names easily by using two global variables that keep track of the occurrences of area and extension delimiters: @= @!area_delimiter:pool_pointer; {the most recent `\.>' or `\.:', if any} @!ext_delimiter:pool_pointer; {the relevant `\..', if any} @y @ The file names we shall deal with have the following structure: If the name contains `\.[', the file area consists of all characters from this character to the end; otherwise the file area is null. If the remaining file name contains `\..', the file extension consists of all such characters from this character to the end, otherwise the file extension is null. We can assume that there is at most one `\.[' and at most one `\..'. @^system dependencies@> We can scan such file names easily by using two global variables that keep track of the occurrences of area and extension delimiters: @= @!area_delimiter:pool_pointer; {the most recent `\.[', if any} @!ext_delimiter:pool_pointer; {the relevant `\..', if any} @z @x @d TEX_area=="TeXinputs:" @.TeXinputs@> @d TEX_font_area=="TeXfonts:" @.TeXfonts@> @y @d TEX_area=="[tex,sys]" @d TEX_font_area=="[tfm,sys]" @z @x else begin if (c=">")or(c=":") then begin area_delimiter:=pool_ptr; ext_delimiter:=0; end else if (c=".")and(ext_delimiter=0) then ext_delimiter:=pool_ptr; @y else begin if c="[" then area_delimiter:=pool_ptr else if c="." then ext_delimiter:=pool_ptr; @z @x if area_delimiter=0 then cur_area:="" else begin cur_area:=str_ptr; incr(str_ptr); str_start[str_ptr]:=area_delimiter+1; end; if ext_delimiter=0 then begin cur_ext:=""; cur_name:=make_string; end else begin cur_name:=str_ptr; incr(str_ptr); str_start[str_ptr]:=ext_delimiter; cur_ext:=make_string; end; @y cur_name:=str_ptr; if ext_delimiter=0 then cur_ext:="" else begin incr(str_ptr); str_start[str_ptr]:=ext_delimiter; cur_ext:=str_ptr; end; if area_delimiter<=str_start[str_ptr] then begin cur_area:=""; incr(str_ptr); str_start[str_ptr]:=pool_ptr; end else begin incr(str_ptr); str_start[str_ptr]:=area_delimiter; cur_area:=make_string; end; @z @x Printing file names: (518) begin print(a); print(n); print(e); @y begin print(n); print(e); print(a); @z @x Converting file names to Pascal strings: (519) allows both lowercase and uppercase letters in the file name. @^system dependencies@> @d append_to_name(#)==begin c:=#; incr(k); @y converts lowercase letters to uppercase. A special convention is used here with respect to font metric files: If the file name is longer than six characters (e.g., `\.{helvetica}' or `\.{oldenglish}'), we abbreviate it by retaining the first three and last three characters (e.g., `\.{helica}' or `\.{oldish}'). @^system dependencies@> @d append_to_name(#)==begin c:=#; incr(k); if (c>="a")and(c<="z") then c:=c-@'40; {convert to uppercase} @z @x for j:=str_start[a] to str_start[a+1]-1 do append_to_name(str_pool[j]); for j:=str_start[n] to str_start[n+1]-1 do append_to_name(str_pool[j]); for j:=str_start[e] to str_start[e+1]-1 do append_to_name(str_pool[j]); @y if (e=".tfm")and(length(n)>6) then begin for j:=str_start[n] to str_start[n]+2 do append_to_name(str_pool[j]); for j:=str_start[n+1]-3 to str_start[n+1]-1 do append_to_name(str_pool[j]); end else for j:=str_start[n] to str_start[n+1]-1 do append_to_name(str_pool[j]); for j:=str_start[e] to str_start[e+1]-1 do append_to_name(str_pool[j]); for j:=str_start[a] to str_start[a+1]-1 do append_to_name(str_pool[j]); @z @x Parsing file names in the buffer: (520) @d format_default_length=20 {length of the |TEX_format_default| string} @d format_area_length=11 {length of its area part} @d format_ext_length=4 {length of its `\.{.fmt}' part} @y @d format_default_length=18 {length of the |TEX_format_default| string} @d format_area_length=9 {length of its area part} @d format_ext_length=4 {length of its `\.{.fmt}' part} @z @x TEX_format_default:='TeXformats:plain.fmt'; @.TeXformats@> @y TEX_format_default:='plain.fmt[tex,sys]'; @z @x |TEX_format_default|. @y |TEX_format_default|; but it actually switches stuff around to keep the file area last. @z @x @!j:integer; {index into |buffer| or |TEX_format_default|} @y @!j:integer; {index into |buffer| or |TEX_format_default|} @!d:integer; {a kludge} @z @x for j:=1 to n do append_to_name(xord[TEX_format_default[j]]); for j:=a to b do append_to_name(buffer[j]); for j:=format_default_length-format_ext_length+1 to format_default_length do append_to_name(xord[TEX_format_default[j]]); @y for j:=a to b do append_to_name(buffer[j]); if b=0 then begin d:=format_default_length-format_area_length+1; n:=format_default_length; end else d:=format_default_length-format_area_length-format_ext_length+1; for j:=d to format_default_length-format_area_length do append_to_name(xord[TEX_format_default[j]]); for j:=format_default_length-n+1 to format_default_length do append_to_name(xord[TEX_format_default[j]]); @z @x The real file names: (525) @ Operating systems often make it possible to determine the exact name (and possible version number) of a file that has been opened. The following routine, which simply makes a \TeX\ string from the value of |name_of_file|, should ideally be changed to deduce the full name of file~|f|, which is the file most recently opened, if it is possible to do this in a \PASCAL\ program. @^system dependencies@> This routine might be called after string memory has overflowed, hence we dare not use `|str_room|'. @p function make_name_string:str_number; var k:1..file_name_size; {index into |name_of_file|} begin if (pool_ptr+name_length>pool_size)or(str_ptr=max_strings) then make_name_string:="?" else begin for k:=1 to name_length do append_char(xord[name_of_file[k]]); make_name_string:=make_string; end; end; function a_make_name_string(var f:alpha_file):str_number; begin a_make_name_string:=make_name_string; end; function b_make_name_string(var f:byte_file):str_number; begin b_make_name_string:=make_name_string; end; function w_make_name_string(var f:word_file):str_number; begin w_make_name_string:=make_name_string; end; @y @ Operating systems often make it possible to determine the exact name (and possible version number) of a file that has been opened. The following routine, due to David Fuchs, deduces the full name of file~|f| on {\mc WAITS}: @^system dependencies@> @^Fuchs, David Raymond@> @p procedure cur_nam(var chan:f@&i@&l@&e;var s:string); extern; @t\2@>@/ function make_name_string(var f:f@&i@&l@&e):str_number; var s:packed array[1..24] of char; @!k:1..24; {file names at {\sc SAIL} have at most 23 characters} begin if (pool_ptr+24>pool_size)or(str_ptr=max_strings) then make_name_string:="?" else begin cur_nam(f,s); k:=1; while ord(s[k])<>0 do begin append_char(xord[s[k]]); incr(k); end; make_name_string:=make_string; end; end; function a_make_name_string(var f:alpha_file):str_number; begin a_make_name_string:=make_name_string(f); end; function b_make_name_string(var f:byte_file):str_number; begin b_make_name_string:=make_name_string(f); end; function w_make_name_string(var f:word_file):str_number; begin w_make_name_string:=make_name_string(f); end; @z @x Line editor gets misspelled file name: (530) begin if interaction=scroll_mode then wake_up_terminal; @y @!i:pool_pointer; {index into |str_pool|} begin if interaction=scroll_mode then wake_up_terminal; @z @x clear_terminal; prompt_input(": "); @; @y clear_terminal; {now we'll fill the line editor's buffer with the old name} for i:=str_start[cur_name] to str_start[cur_name+1]-1 do pto_chr(xchr[str_pool[i]]); for i:=str_start[cur_ext] to str_start[cur_ext+1]-1 do pto_chr(xchr[str_pool[i]]); for i:=str_start[cur_area] to str_start[cur_area+1]-1 do pto_chr(xchr[str_pool[i]]); ptwr1w(0,@'214); {control-formfeed returns cursor to start of line} prompt_input(": "); @; @z @x Reading the first line of a file, again: (538) @ Here we have to remember to tell the |input_ln| routine not to start with a |get|. If the file is empty, it is considered to contain a single blank line. @^system dependencies@> @^empty line at end of file@> @= begin if not input_ln(cur_file,false) then do_nothing; @y @ Here we have to remember to tell |input_ln| not to do the first |get|, and we also want to skip over a file directory page. An empty file is considered to contain a single blank line. @^system dependencies@> @^empty line at end of file@> @= begin if input_ln(cur_file,false) then begin if(last-start=29)and(buffer[start]="C")and(buffer[start+8]=@'26) then begin while (cur_file^<>chr(form_feed))and(not eof(cur_file)) do begin read_ln(cur_file); read(cur_file,aux_buf:temp_ptr); end; {skip the directory} buffer[start]:=form_feed; last:=start+1; end; end; page:=1; @z @x new DVI opcodes [585-586] \yskip\noindent Commands 250--255 are undefined at the present time. @ @d set_char_0=0 {typeset character 0 and move right} @y \yskip\hang|begin_reflect| 250. Begin a (possibly recursive) reflected segment. \yskip\hang|end_reflect| 251. End a (possibly recursive) reflected segment. \yskip\noindent Commands 250--255 are undefined in normal \.{DVI} files, but 250 and 251 are permitted in the special `\.{DVI-IVD}' files produced by this variant of \TeX. @ @d begin_reflect=250 {begin a reflected segment (not normally allowed)} @d end_reflect=251 {end a reflected segment (not normally allowed)} @d set_char_0=0 {typeset character 0 and move right} @z @x The DVI output buffer: (594) @!dvi_index=0..dvi_buf_size; {an index into the output buffer} @y @!dvi_index=0..dvi_buf_size; {an index into the output buffer} @!packed_bytes=packed array[dvi_index] of eight_bits; {buffer for \.{DVI} output} @z @x @!dvi_buf:array[dvi_index] of eight_bits; {buffer for \.{DVI} output} @y @!dvi_buf:packed_bytes; {buffer for \.{DVI} output} @z @x @p procedure write_dvi(@!a,@!b:dvi_index); var k:dvi_index; begin for k:=a to b do write(dvi_file,dvi_buf[k]); end; @y @p procedure ary_out(var f:file;@!b:packed_bytes; @!o,@!c:integer); extern;@t\2@>@# procedure write_dvi(@!a,@!b:dvi_index); begin ary_out(dvi_file,dvi_buf,a div 4,(b+1-a)div 4); end; @z @x changes to ship_out [638] begin if tracing_output>0 then @y begin LR_ptr:=get_avail; info(LR_ptr):=0; {|begin_L_code| at outer level} if tracing_output>0 then @z @x (module 639) flush_node_list(p); @y flush_node_list(p); @; @z @x "r DVIdover": (642) b_close(dvi_file); @y b_close(dvi_file); if pseudo_typein=0 then begin k:=selector; selector:=new_string; pool_ptr:=str_start[str_ptr]; print("r DVIdover;"); print(output_file_name); selector:=k; if pool_ptr; hpack:=r; @z @x Page numbers on over/underfull box messages: (663) print_int(line); @y print_int(line); if page>1 then begin print(", p."); print_int(page); end; @z @x print_int(line); @y print_int(line); if page>1 then begin print(", p."); print_int(page); end; @z @x post_line_break stuff [877] begin @; @z @x (module 880) @; @y @; @; @; @; @z @x new horizontal command [1090] vmode+ex_space:@t@>@;@/ @y vmode+ex_space,vmode+LR:@t@>@;@/ @z @x math in text is L-text [module 1196] begin tail_append(new_math(math_surround,before)); @y begin tail_append(new_math(math_surround,before)); @; @z @x (module 1196, continued) tail_append(new_math(math_surround,after)); @y @; tail_append(new_math(math_surround,after)); @z @x The endgame: (1335) @= @y The new stuff at {\mc SAIL} has to do with preparing for what the user presumably wants to do next, by typing it for him/her. @= @z @x end; @y if (pseudo_typein<>0)and(interaction>batch_mode) then begin write_ln(term_out); for k:=str_start[pseudo_typein] to str_start[pseudo_typein+1]-1 do pto_chr(xchr[str_pool[k]]); end; end; @z @x whatsit processing [1341] @d special_node=3 {|subtype| in whatsits that represent \.{\\special} things} @y @d special_node=3 {|subtype| in whatsits that represent \.{\\special} things} @d LR_node=4 {|subtype| in whatsits that represent \.{\\beginL}, etc.} @d LR_type(#)==mem[#+1].int {the sub-subtype} @z @x (module 1344) @d immediate_code=4 {command modifier for \.{\\immediate}} @= @y @d immediate_code=4 {command modifier for \.{\\immediate}} @d begin_L_code=0 {command modifier for \.{\\beginL}} @d begin_R_code=1 {command modifier for \.{\\beginR}} @d end_L_code=2 {command modifier for \.{\\endL}} @d end_R_code=3 {command modifier for \.{\\endR}} @d begin_LR(#)==(LR_type(#)= primitive("beginL",LR,begin_L_code);@/ @!@:begin_L_}{\.{\\beginL} primitive@> primitive("beginR",LR,begin_R_code);@/ @!@:begin_R_}{\.{\\beginR} primitive@> primitive("endL",LR,end_L_code);@/ @!@:end_L_}{\.{\\endL} primitive@> primitive("endR",LR,end_R_code);@/ @!@:end_R_}{\.{\\endR} primitive@> @z @x (module 1346) @ @= @y @ @= LR: case chr_code of begin_L_code: print_esc("beginL"); begin_R_code: print_esc("beginR"); end_L_code: print_esc("endL"); othercases print_esc("endR") endcases; @z @x (module 1356) othercases print("whatsit?") @y LR_node: case LR_type(p) of begin_L_code: print_esc("beginL"); begin_R_code: print_esc("beginR"); end_L_code: print_esc("endL"); othercases print_esc("endR") endcases; othercases print("whatsit?") @z @x (module 1357) close_node: begin r:=get_node(small_node_size); words:=small_node_size; @y close_node,LR_node: begin r:=get_node(small_node_size); words:=small_node_size; @z @x (module 1358) close_node: free_node(p,small_node_size); @y close_node,LR_node: free_node(p,small_node_size); @z @x (module 1360) @ @=do_nothing @y @ @= if subtype(p)=LR_node then @ @z @x (module 1366) @ @= out_what(p) @y @ @= if subtype(p)<>LR_node then out_what(p) else @ @z @x Final system-dependent changes: [1376] This section should be replaced, if necessary, by changes to the program that are necessary to make \TeX\ work at a particular installation. It is usually best to design your change file so that all changes to previous sections preserve the section numbering; then everybody's version will be consistent with the published program. More extensive changes, which introduce new sections, can be inserted here; then only the index itself will get a new section number. @^system dependencies@> @y Now we do the main work required for mixed-direction texts. @= hmode+LR: begin new_whatsit(LR_node,small_node_size); LR_type(tail):=cur_chr; end; mmode+LR: report_illegal_case; @ @= @!LR_ptr,@!LR_tmp:pointer; {stack of LR codes and temp for manipulation} @ @= function new_LR(@!s:small_number): pointer; var p: pointer; {the new node} begin p:=get_node(small_node_size); type(p):=whatsit_node; subtype(p):=LR_node; LR_type(p):=s; new_LR:=p; end; @ @= function safe_info(@!p:pointer): integer; begin if p=null then safe_info:=-1@+else safe_info:=info(p); end; @ @= tail_append(new_LR(begin_L_code)) @ @= tail_append(new_LR(end_L_code)) @ A number of routines are based on a stack of one-word nodes whose |info| fields contain either |begin_L_code| or |begin_R_code|. The top of the stack is pointed to by |LR_ptr|, and an auxiliary variable |LR_tmp| is available for stack manipulation. @d push_LR(#)==begin LR_tmp:=get_avail; info(LR_tmp):=LR_type(#); link(LR_tmp):=LR_ptr; LR_ptr:=LR_tmp; end @d pop_LR==begin LR_tmp:=LR_ptr; LR_ptr:=link(LR_tmp); free_avail(LR_tmp); end @=while LR_ptr<>null do pop_LR @ @= while LR_ptr<>null do begin LR_tmp:=new_LR(info(LR_ptr)); link(LR_tmp):=link(temp_head); link(temp_head):=LR_tmp; pop_LR; end @ @= q:=link(temp_head); while q<>cur_break(cur_p) do begin if notis_char_node(q) then if type(q)=whatsit_node then if subtype(q)=LR_node then if begin_LR(q) then push_LR(q) else if LR_ptr<>null then if info(LR_ptr)=begin_LR_type(q) then pop_LR; q:=link(q); end @ We use the fact that |q| now points to the node with \.{\\rightskip} glue. @= if LR_ptr<>null then begin s:=temp_head; r:=link(s); while r<>q do begin s:=r; r:=link(s); end; r:=LR_ptr; while r<>null do begin LR_tmp:=new_LR(info(r)+end_L_code); link(s):=LR_tmp; s:=LR_tmp; r:=link(r); end; link(s):=q; end @ @= if begin_LR(p) then push_LR(p) else if safe_info(LR_ptr)=begin_LR_type(p) then pop_LR else begin incr(LR_problems); while link(q)<>p do q:=link(q); link(q):=link(p); free_node(p,small_node_size); p:=q; end @ @= if LR_ptr<>null then begin while link(q)<>null do q:=link(q); repeat link(q):=new_LR(info(LR_ptr)+end_L_code); q:=link(q); LR_problems:=LR_problems+10000; pop_LR; until LR_ptr=null; end; if LR_problems>0 then begin print_ln; print_nl("\endL or \endR problem (");@/ print_int(LR_problems div 10000); print(" missing, ");@/ print_int(LR_problems mod 10000); print(" extra");@/ LR_problems:=0; goto common_ending; end @ @= if begin_LR(p) then begin if safe_info(LR_ptr)<>LR_type(p) then begin synch_h; synch_v; dvi_out(begin_reflect); end; push_LR(p); end else if safe_info(LR_ptr)=begin_LR_type(p) then begin pop_LR; if info(LR_ptr)+end_L_code<>LR_type(p) then begin synch_h; synch_v; dvi_out(end_reflect); end; end else confusion("LR") @:this can't happen LR}{\quad LR@> @ Finally, here are the remaining things needed to make the implementation complete at {\mc SAIL}. @^system dependencies@> @ The |pseudo_typein| variable is set nonzero if the |error| routine uses the `\.E' option to exit and edit. @= @!pseudo_typein:str_number; @ @= pseudo_typein:=0; page:=0; @ The |mem| array is declared after the other global variables, so that our friendly \PASCAL\ will compile things correctly. @= @!mem : array[mem_min..mem_max] of memory_word; {the big dynamic storage area} @z