learn-cmd-syntax.sty

   1 \usepackage{xparse}
   2 \ExplSyntaxOn
   3 % By egreg, http://tex.stackexchange.com/questions/40404/parsing-latex-to-output-number-of-arguments-for-each-command-defined
   4 %
   5 % Defining commands like this
   6 %   \newcommand{\xaa}{abc}
   7 %   \newcommand*{\xab}[1]{abc}
   8 %   \newcommand{\xac}[2][cccc]{abc}
   9 %   \renewcommand{\phi}{\varphi}
  10 %   \newenvironment{xad}{}{}
  11 %   \newenvironment{xae}[1]{}{}
  12 %   \newenvironment{xaf}[2][sss]{}{}
  13 % results in this output in myfile.cmd:
  14 %   command,\xaa ,0,0,
  15 %   command,\xab *,1,0,
  16 %   command,\xac ,1,1,cccc
  17 %   command,\phi ,0,0,
  18 %   environment,xad,0,0,
  19 %   environment,xae,1,0,
  20 %   environment,xaf,1,1,sss
  21 % The fields in the output are:
  22 %   (command|environment),name,n-required-args,n-optional-args,default
  23 % Extraneous whitespace occurs in <name> and should be filtered out.
  24 %
  25 % Define the command that will start the working; we'll redefine \newcommand
  26 % so that \newcommand{\xac}[2][cccc]{abc} will execute
  27 %
  28 %    \command_check:w { \command_check_newcommand:w }{ command } {\xab}
  29 %
  30 % #1 = \newcommand|\renewcommand|\newenvironment|\renewenvironment (in new form)
  31 % #2 = command|environment
  32 % #3 = the possible *
  33 % #4 = the argument to \newcommand
  34 % #5 = the number of arguments
  35 % #6 = the possible optional argument
  36 %
  37 % We check if the last argument is missing and take the appropriate action
  38 \NewDocumentCommand{ \command_check:w }{m m s m O{0} o}
  39   {
  40    \IfBooleanTF{#3}
  41      { \tl_gset:Nn \g_command_check_star_tl { * } \bool_gset_true:N \g_command_check_star_bool }
  42      { \tl_gset:Nn \g_command_check_star_tl { } \bool_gset_false:N \g_command_check_star_bool }
  43    \IfNoValueTF{#6}
  44      { \command_check_noopt:nnnn {#1} {#2} {#4} {#5} }
  45      { \command_check_opt:nnnnn {#1} {#2} {#4} {#5} {#6} }
  46   }
  47 % \StartSaveCommands sets up the checks, first by creating aliases for the kernel commands
  48 % and then redefining them as explained above
  49 \NewDocumentCommand{\StartSaveCommands}{}
  50   {
  51    \cs_set_eq:NN \command_check_newcommand:w \newcommand
  52    \cs_set_eq:NN \command_check_renewcommand:w \renewcommand
  53    \cs_set_eq:NN \command_check_newenvironment:w \newenvironment
  54    \cs_set_eq:NN \command_check_renewenvironment:w \renewenvironment
  55    \cs_set:Npn \newcommand { \command_check:w {\command_check_newcommand:w}{command} }
  56    \cs_set:Npn \renewcommand { \command_check:w {\command_check_renewcommand:w}{command} }
  57    \cs_set:Npn \newenvironment { \command_check:w {\command_check_newenvironment:w}{environment} }
  58    \cs_set:Npn \renewenvironment { \command_check:w {\command_check_renewenvironment:w}{environment} }
  59   }
  60 % \StopSaveCommands restores the kernel commands
  61 \NewDocumentCommand{\StopSaveCommands}{}
  62   {
  63    \cs_set_eq:NN \newcommand \command_check_newcommand:w
  64    \cs_set_eq:NN \renewcommand \command_check_renewcommand:w
  65    \cs_set_eq:NN \newenvironment \command_check_newenvironment:w
  66    \cs_set_eq:NN \renewenvironment \command_check_renewenvironment:w
  67   }
  68 % \WriteSaveCommands will take care of writing out the list of commands
  69 % with their number of arguments
  70 \NewDocumentCommand{\WriteSaveCommands}{}
  71   {
  72    \iow_open:Nn \g_command_check_write { \jobname.cmd }
  73    \seq_map_inline:Nn \g_command_check_seq {\iow_now:Nx \g_command_check_write { ##1 } }
  74   }
  75 % Allocate a write stream
  76 \iow_new:N \g_command_check_write
  77 % If there's no optional argument, say \newcommand{\xab}[1]{aaa},
  78 % we want to write out "command,\xab ,1,0", so we store that
  79 % string into an item appended to the sequence \g_command_check_seq
  80 \cs_new:Npn \command_check_noopt:nnnn #1 #2 #3 #4
  81   {
  82    \seq_gput_right:Nx \g_command_check_seq
  83      {
  84       #2 ,
  85       \tl_to_str:n{#3}\bool_if:NT\g_command_check_star_bool{*}
  86       , #4, 0,
  87      }
  88    \exp_after:wN #1 \g_command_check_star_tl {#3} [#4]
  89   }
  90 % If there's an optional argument, say \newcommand{\xac}[2][cccc]{abc},
  91 % we want to write out "command,\xac,1,1[cccc]; everything as before,
  92 % but we decrease by 1 the number of stated arguments
  93 \cs_new:Npn \command_check_opt:nnnnn #1 #2 #3 #4 #5
  94   {
  95    \seq_gput_right:Nx \g_command_check_seq
  96      {
  97       #2 \bool_if:NT \g_command_check_star_bool {*}, \tl_to_str:n {#3} ,
  98       \int_to_arabic:n {#4-1} , 1,\tl_to_str:n{#5}
  99      }
 100    \exp_after:wN #1 \g_command_check_star_tl {#3}[#4][#5]
 101   }
 102 % Allocate the sequence, the token list variable and the boolean
 103 \seq_new:N \g_command_check_seq
 104 \tl_new:N \g_command_check_star_tl
 105 \bool_new:N \g_command_check_star_bool
 106 \ExplSyntaxOff