l3doc: base form conditional \<name>:<arg spec>TF is indexed unconditionally

[muzimuzhi]

Not all conditionals have a \<name>:<arg spec>TF base form, but currently the T and F form usages are always indexed as the TF base form.

For example \file_if_exist_input:nF has no T and TF forms, but \file_if_exist_input:nTF, an undefined function is the only form listed in the "Index" chapter of interface3.pdf.

Here's a possible patch that makes \__codedoc_key_get_base:nN aware of \DoNotIndex records (stored in \l__doc_donotindex_seq since doc v3). Then one can use \DoNotIndex{\file_if_exist_input:nTF} to make \file_if_exist_input:nF indexed as itself.

diff --git a/l3kernel/l3doc.dtx b/l3kernel/l3doc.dtx
index 039ee83..39ed45d 100644
--- a/l3kernel/l3doc.dtx
+++ b/l3kernel/l3doc.dtx
@@ -1173,15 +1173,15 @@ and all files in that bundle must be distributed together.
   {
     \str_case:nnTF {#1}
       {
-        { N } { N }
-        { c } { N }
-        { n } { n }
-        { o } { n }
-        { f } { n }
-        { e } { n }
-        { x } { n }
-        { V } { n }
-        { v } { n }
+        { N } { \token_to_str:N N }
+        { c } { \token_to_str:N N }
+        { n } { \token_to_str:N n }
+        { o } { \token_to_str:N n }
+        { f } { \token_to_str:N n }
+        { e } { \token_to_str:N n }
+        { x } { \token_to_str:N n }
+        { V } { \token_to_str:N n }
+        { v } { \token_to_str:N n }
       }
       { \@@_signature_base_form_aux:n }
       { \@@_signature_base_form_aux:w #1 }
@@ -1207,7 +1207,7 @@ and all files in that bundle must be distributed together.
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}{\@@_split_function_do:nn, \@@_split_function_do:on}
+% \begin{macro}{\@@_split_function_do:nn}
 % \begin{macro}{\@@_get_function_name:n, \@@_get_function_signature:n}
 % \begin{macro}{\@@_split_function_auxi:w, \@@_split_function_auxii:w}
 %   Similar to internal functions defined in \pkg{l3basics}, but here we
@@ -1234,7 +1234,6 @@ and all files in that bundle must be distributed together.
       { ##1 {##2} }
   }
 \exp_args:No \@@_tmpa:w { \token_to_str:N : }
-\cs_generate_variant:Nn \@@_split_function_do:nn { o }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -1252,9 +1251,13 @@ and all files in that bundle must be distributed together.
   {
     \@@_if_almost_str:nTF {#1}
       {
-        \@@_key_get_base_TF:nN {#1} \l_@@_tmpa_tl
-        \__kernel_tl_set:Nx #2
-          { \@@_split_function_do:on \l_@@_tmpa_tl { \@@_base_form_aux:nnN } }
+        \__kernel_tl_set:Nx \l_@@_tmpa_tl
+          { \@@_split_function_do:nn {#1} { \@@_base_form_aux:nnN } }
+        \@@_key_get_base_TF:oN \l_@@_tmpa_tl \l_@@_tmpb_tl
+        \seq_if_in:NxTF \l__doc_donotindex_seq
+          { \exp_after:wN \use_none:n \l_@@_tmpb_tl } % or \tl_tail:N
+          { \tl_set_eq:NN #2 \l_@@_tmpa_tl }
+          { \tl_set_eq:NN #2 \l_@@_tmpb_tl }
       }
       { \tl_set:Nn #2 {#1} }
   }
@@ -1278,6 +1281,7 @@ and all files in that bundle must be distributed together.
       }
     \exp_not:N \prg_break_point:
   }
+\cs_generate_variant:Nn \@@_key_get_base_TF:nN { o }
 \cs_new:Npn \@@_base_form_aux:nnN #1#2#3
   {
     \exp_not:n {#1}

This slows down l3doc further more, since \seq_if_in:NnTF takes linear time. Storing \DoNotIndex records in a l3key module would reduce the time complexity I think.

A full example to test the patch

% !TeX TS-program = pdflatex -interaction=nonstopmode %.tex | makeindex -s gind.ist -o %.ind %.idx | pdflatex -interaction=nonstopmode %.tex | pdflatex -interaction=nonstopmode %.tex
\documentclass{l3doc}

\ExplSyntaxOn
\cs_generate_variant:Nn \__codedoc_key_get_base_TF:nN { o }

\cs_gset_protected:Npn \__codedoc_key_get_base:nN #1#2
  {
    \__codedoc_if_almost_str:nTF {#1}
      {
        \__kernel_tl_set:Nx \l__codedoc_tmpa_tl
          { \__codedoc_split_function_do:nn {#1} { \__codedoc_base_form_aux:nnN } }
        \exp_args:No
        \__codedoc_key_get_base_TF:nN \l__codedoc_tmpa_tl \l__codedoc_tmpb_tl
        \seq_if_in:NxTF \l__doc_donotindex_seq
          { \exp_after:wN \use_none:n \l__codedoc_tmpb_tl } % or \tl_tail:N
          { \tl_set_eq:NN #2 \l__codedoc_tmpa_tl }
          { \tl_set_eq:NN #2 \l__codedoc_tmpb_tl }
      }
      { \tl_set:Nn #2 {#1} }
  }

\cs_gset:Npn \__codedoc_signature_base_form_aux:n #1
  {
    \str_case:nnTF {#1}
      {
        { N } { \token_to_str:N N }
        { c } { \token_to_str:N N }
        { n } { \token_to_str:N n }
        { o } { \token_to_str:N n }
        { f } { \token_to_str:N n }
        { e } { \token_to_str:N n }
        { x } { \token_to_str:N n }
        { V } { \token_to_str:N n }
        { v } { \token_to_str:N n }
      }
      { \__codedoc_signature_base_form_aux:n }
      { \__codedoc_signature_base_form_aux:w #1 }
  }
\ExplSyntaxOff

\ExplSyntaxOn
\DoNotIndex{\file_if_exist_input:nTF, \mymod_no_TF_form:nTF}
\ExplSyntaxOff

\begin{document}
\begin{function}{\file_if_exist_input:n, \file_if_exist_input:nF}
  No \cs[no-index]{file_if_exist_input:nTF}.
\end{function}

\begin{function}[TF]{\mymod_has_TF_form:n, \mymod_has_TF_form:o}
  description
\end{function}

\begin{function}{\mymod_no_TF_form:nT, \mymod_no_TF_form:nF,
                 \mymod_no_TF_form:oT, \mymod_no_TF_form:oF}
  No \cs[no-index]{mymod_no_TF_form:oTF} nor \cs[no-index]{mymod_no_TF_form:nTF}.
\end{function}

\begin{macro}{\mymod_no_TF_form:nT, \mymod_no_TF_form:nF}
    \begin{macrocode}
\cs_new:Nn \mymod_no_TF_form:nT {}
\cs_new:Nn \mymod_no_TF_form:nF {}
%    \end{macrocode}
\end{macro}

\bigskip
Used in \cs[no-index]{cs}\Arg{csname}, base forms
\begin{itemize}
  \item \cs{file_if_exist_input:n}, \cs{file_if_exist_input:nF}
  \item \cs{mymod_has_TF_form:nT},  \cs{mymod_has_TF_form:nF}
  \item \cs{mymod_no_TF_form:nT},   \cs{mymod_no_TF_form:nF}
\end{itemize}
and variant forms
\begin{itemize}
  \item \cs{mymod_has_TF_form:oT},  \cs{mymod_has_TF_form:oF}
  \item \cs{mymod_no_TF_form:oT},   \cs{mymod_no_TF_form:oF}
\end{itemize}

\PrintIndex
\end{document}

• Without patch
  
• With patch
  

[josephwright]

Could you put your patch in as a PR?

[muzimuzhi]

Related to #892 (actually almost identical, current issue just used a more general title)

I was thinking about adding some caching for quicker resolving, but didn't have a try.