diff options
author | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
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committer | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
commit | e0c6872cf40896c7be36b11dcc744620f10adf1d (patch) | |
tree | 60335e10d2f4354b0674ec22d7b53f0f8abee672 /language/xettex/waits-xe.ch |
Initial commit
Diffstat (limited to 'language/xettex/waits-xe.ch')
-rw-r--r-- | language/xettex/waits-xe.ch | 1979 |
1 files changed, 1979 insertions, 0 deletions
diff --git a/language/xettex/waits-xe.ch b/language/xettex/waits-xe.ch new file mode 100644 index 0000000000..9cf606f28c --- /dev/null +++ b/language/xettex/waits-xe.ch @@ -0,0 +1,1979 @@ +@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@> + +@<Set init...@>= +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. + +@<Set initial values...@>= +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. + +@<Glob...@>= +@!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} + +@<Glob...@>= +@!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@> + +@<Glob...@>= +@!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} + +@<Error handling procedures@>= +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<last)and(buffer[loc]=" ") do incr(loc); + if loc<last then + begin init_terminal:=true; + return; {return unless the line was all blank} + end; + write_ln(term_out,'Please type the name of your input file.'); + end; +exit:end; +@y +@ The following program does the required initialization +and accepts interrupts and also retrieves a possible command line, using +new system routines due to David R. Fuchs. +@^Fuchs, David Raymond@> + +@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<l)and(tmp_cor_buf[loc]<>':=') do incr(loc); + incr(loc); + while loc<l do + begin if tmp_cor_buf[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<last)and(buffer[loc]=" ") do incr(loc); + if loc<last then + begin init_terminal:=true; + return; {return unless the line was all blank} + end; + if line_found then + write_ln(term_out,'Please type the name of your input file.'); + wake_up_terminal; write(term_out,'**'); update_terminal; +@.**@> + 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) +@<Character |k| cannot be printed@>= + (k<" ")or(k>"~") +@y +@<Character |k| cannot be printed@>= + (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<max_strings then + begin pseudo_typein:=str_ptr; incr(str_ptr); + str_start[str_ptr]:=pool_ptr; + end; {|make_string| not declared |forward|} + selector:=term_and_log; interaction:=scroll_mode; jump_out; + end; +@z + +@x Changes for 36-bit machines: (110) +The values defined here are recommended for most 32-bit computers. + +@d min_quarterword=0 {smallest allowable value in a |quarterword|} +@d max_quarterword=255 {largest allowable value in a |quarterword|} +@d min_halfword==0 {smallest allowable value in a |halfword|} +@d max_halfword==65535 {largest allowable value in a |halfword|} +@y +The values defined here are recommended for most 36-bit computers. + +@d min_quarterword=0 {smallest allowable value in a |quarterword|} +@d max_quarterword=511 {largest allowable value in a |quarterword|} +@d min_halfword==0 {smallest allowable value in a |halfword|} +@d max_halfword==262143 {largest allowable value in a |halfword|} +@z + +@x Eliminating addition/subtraction of zero: (112) +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|. +@^inner loop@>@^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@<Declare functions needed for special kinds of nodes@> +@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<limit then for k:=start to limit-1 do print(buffer[k]); + first:=limit; prompt_input("=>"); {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} + +@<Error handling procedures@>= +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<last)and(buffer[loc]=" ") do incr(loc); + if loc<last then + begin init_terminal:=true; + return; {return unless the line was all blank} + end; + write_ln(term_out,'Please type the name of your input file.'); + end; +exit:end; +@y +@ The following program does the required initialization +and accepts interrupts and also retrieves a possible command line, using +new system routines due to David R. Fuchs. +@^Fuchs, David Raymond@> + +@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<l)and(tmp_cor_buf[loc]<>':=') do incr(loc); + incr(loc); + while loc<l do + begin if tmp_cor_buf[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<last)and(buffer[loc]=" ") do incr(loc); + if loc<last then + begin init_terminal:=true; + return; {return unless the line was all blank} + end; + if line_found then + write_ln(term_out,'Please type the name of your input file.'); + wake_up_terminal; write(term_out,'**'); update_terminal; +@.**@> + 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) +@<Character |k| cannot be printed@>= + (k<" ")or(k>"~") +@y +@<Character |k| cannot be printed@>= + (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<max_strings then + begin pseudo_typein:=str_ptr; incr(str_ptr); + str_start[str_ptr]:=pool_ptr; + end; {|make_string| not declared |forward|} + selector:=term_and_log; interaction:=scroll_mode; jump_out; + end; +@z + +@x Changes for 36-bit machines: (110) +The values defined here are recommended for most 32-bit computers. + +@d min_quarterword=0 {smallest allowable value in a |quarterword|} +@d max_quarterword=255 {largest allowable value in a |quarterword|} +@d min_halfword==0 {smallest allowable value in a |halfword|} +@d max_halfword==65535 {largest allowable value in a |halfword|} +@y +The values defined here are recommended for most 36-bit computers. + +@d min_quarterword=0 {smallest allowable value in a |quarterword|} +@d max_quarterword=511 {largest allowable value in a |quarterword|} +@d min_halfword==0 {smallest allowable value in a |halfword|} +@d max_halfword==262143 {largest allowable value in a |halfword|} +@z + +@x Eliminating addition/subtraction of zero: (112) +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|. +@^inner loop@>@^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@<Declare functions needed for special kinds of nodes@> +@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<limit then for k:=start to limit-1 do print(buffer[k]); + first:=limit; prompt_input("=>"); {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@> + +@<Input the first line of |read_file[m]|@>= +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@> + +@<Input the first line of |read_file[m]|@>= +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. + +@<Glob...@>= +@!skip_line:integer; {skipping began here} +@y +where skipping began, for use in error messages. Also the page number. + +@<Glob...@>= +@!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: + +@<Glob...@>= +@!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: + +@<Glob...@>= +@!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(": "); @<Scan file name in the buffer@>; +@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(": "); @<Scan file name in the buffer@>; +@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@> + +@<Read the first line...@>= +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@> + +@<Read the first line...@>= +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); @<Flush the LR stack@>; +@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<pool_size then + if str_ptr<max_strings then {|overflow| can't occur} + pseudo_typein:=make_string; + end; +@z + +@x hpack changes [649] +begin r:=get_node(box_node_size); type(r):=hlist_node; +@y +@!LR_ptr,@!LR_tmp:pointer; {for LR stack maintenance} +@!LR_problems:integer; {counts missing begins and ends} +begin LR_ptr:=null; LR_problems:=0; +r:=get_node(box_node_size); type(r):=hlist_node; +@z +@x (module 649, continued) +exit: hpack:=r; +@y +exit: @<Check for LR anomalies at the end of |hpack|@>; +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 @<Reverse the links of the relevant passive nodes, setting |cur_p| to the +@y +@!LR_ptr,@!LR_tmp:pointer; {for LR stack maintenance} +begin LR_ptr:=null; + @<Reverse the links of the relevant passive nodes, setting |cur_p| to the +@z +@x (module 877, continued) +prev_graf:=best_line-1; +@y +prev_graf:=best_line-1; +@<Flush the LR stack@>; +@z +@x (module 880) +@<Modify the end of the line to reflect the nature of the break and to include + \.{\\rightskip}; also set the proper value of |disc_break|@>; +@y +@<Insert LR nodes at the beginning of the current line@>; +@<Adjust the LR stack based on LR nodes in this line@>; +@<Modify the end of the line to reflect the nature of the break and to include + \.{\\rightskip}; also set the proper value of |disc_break|@>; +@<Insert LR nodes at the end of the current line@>; +@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)); +@<Append a |begin_L| to the tail of the current list@>; +@z +@x (module 1196, continued) +tail_append(new_math(math_surround,after)); +@y +@<Append an |end_L| to the tail of the current list@>; +tail_append(new_math(math_surround,after)); +@z + +@x The endgame: (1335) +@<Last-minute...@>= +@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. + +@<Last-minute...@>= +@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}} + +@<Put each...@>= +@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(#)<end_L_code) +@d begin_LR_type(#)==(LR_type(#)-end_L_code) + +@<Put each...@>= +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) +@ @<Cases of |print_cmd_chr|...@>= +@y +@ @<Cases of |print_cmd_chr|...@>= +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) +@ @<Incorporate a whatsit node into an hbox@>=do_nothing +@y +@ @<Incorporate a whatsit node into an hbox@>= +if subtype(p)=LR_node then @<Adjust the LR stack for the |hpack| routine@> +@z +@x (module 1366) +@ @<Output the whatsit node |p| in an hlist@>= +out_what(p) +@y +@ @<Output the whatsit node |p| in an hlist@>= +if subtype(p)<>LR_node then out_what(p) +else @<Output a reflection instruction if the direction has changed@> +@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. + +@<Cases of |main_control| that build...@>= +hmode+LR: begin new_whatsit(LR_node,small_node_size); LR_type(tail):=cur_chr; + end; +mmode+LR: report_illegal_case; + +@ @<Glob...@>= +@!LR_ptr,@!LR_tmp:pointer; {stack of LR codes and temp for manipulation} + +@ @<Declare functions needed for special kinds of nodes@>= +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; + +@ @<Declare functions needed for special kinds of nodes@>= +function safe_info(@!p:pointer): integer; +begin if p=null then safe_info:=-1@+else safe_info:=info(p); +end; + +@ @<Append a |begin_L| to the tail of the current list@>= +tail_append(new_LR(begin_L_code)) + +@ @<Append an |end_L| to the tail of the current list@>= +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 + +@<Flush the LR stack@>=while LR_ptr<>null do pop_LR + +@ @<Insert LR nodes at the beginning of the current line@>= +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 + +@ @<Adjust the LR stack based on LR nodes in this line@>= +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. + +@<Insert LR nodes at the end of the current line@>= +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 + +@ @<Adjust the LR stack for the |hpack| routine@>= +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 + +@ @<Check for LR anomalies at the end of |hpack|@>= +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 + +@ @<Output a reflection instruction if the direction has changed@>= +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. + +@<Glob...@>= +@!pseudo_typein:str_number; + +@ @<Set init...@>= +pseudo_typein:=0; page:=0; + +@ The |mem| array is declared after the other global variables, so +that our friendly \PASCAL\ will compile things correctly. + +@<Glob...@>= +@!mem : array[mem_min..mem_max] of memory_word; {the big dynamic storage area} +@z |