\cctab_const:Nn raises "Inconsistent local/global assignment" errors

[muzimuzhi]

\documentclass{article}

\ExplSyntaxOn
\debug_on:n { check-declarations }

\cctab_const:Nn \c_my_cctab {}
\ExplSyntaxOff

\begin{document}
\end{document}

Compiled with non-LuaLaTeX, this raises three "Inconsistent local/global assignment" errors.

• First error is raised by \cctab_new:N \c_..._cctab used by \cctab_const:Nn
• Second one is raised by \intarray_new:N \c_..._cctab used by \__cctab_new:N, which is used by \cctab_new:N
• Third one is raised by \cctab_gset:N \c_..._cctab used by \cctab_const:Nn

With LuaLaTeX, only the first and last are raised because \__cctab_new:n is based on \newcatcodetable not intarray.

! LaTeX Error: Inconsistent local/global assignment

For immediate help type H <return>.
 ...                                              
                                                  
l.6 \cctab_const:Nn \c_my_cctab {}
                                  

This is a coding error.

Global assignment to a constant variable '\c_my_cctab'.

latex3/l3kernel/l3cctab.dtx

Lines 802 to 806 in 35b15d8

	\cs_new_protected:Npn \cctab_const:Nn #1#2
	{
	\cctab_new:N #1
	\cctab_gset:Nn #1 {#2}
	}

latex3/l3kernel/l3cctab.dtx

Lines 294 to 315 in 35b15d8

	\cs_new_protected:Npn \@@_new:N #1
	{ \intarray_new:Nn #1 { 257 } }
	\cs_new_protected:Npn \@@_gstore:Nnn #1#2#3
	{ \intarray_gset:Nnn #1 { \int_eval:n { #2 + 1 } } {#3} }
	\cs_new_protected:Npn \cctab_new:N #1
	{
	\__kernel_chk_if_free_cs:N #1
	\@@_new:N #1
	\int_step_inline:nn { 256 }
	{ \__kernel_intarray_gset:Nnn #1 {##1} { 12 } }
	\__kernel_intarray_gset:Nnn #1 { 257 } { 13 }
	\@@_gstore:Nnn #1 { 0 } { 9 }
	\@@_gstore:Nnn #1 { 13 } { 5 }
	\@@_gstore:Nnn #1 { 32 } { 10 }
	\@@_gstore:Nnn #1 { 37 } { 14 }
	\int_step_inline:nnn { 65 } { 90 }
	{ \@@_gstore:Nnn #1 {##1} { 11 } }
	\@@_gstore:Nnn #1 { 92 } { 0 }
	\int_step_inline:nnn { 97 } { 122 }
	{ \@@_gstore:Nnn #1 {##1} { 11 } }
	\@@_gstore:Nnn #1 { 127 } { 15 }
	}

The first and third errors can be avoided by rewriting \cctab_const:Nn in implementations of \cctab_new:N and \cctab_gset:Nn, for example

\documentclass{article}

\ExplSyntaxOn
\cs_undefine:N \cctab_const:Nn
\cs_new_protected:Npn \cctab_const:Nn #1#2
  {
    \__kernel_chk_if_free_cs:N #1
    \__cctab_new:N #1
    \group_begin:
      \cctab_select:N \c_initex_cctab
      #2 \scan_stop:
      \__cctab_gset:n {#1}
    \group_end:
  }

\debug_on:n { check-declarations }

\cctab_const:Nn \c_my_cctab {}
\ExplSyntaxOff

\begin{document}
\end{document}

but to avoid the second error it seems \intarray_const:Nnn <intarray var> {<size>} { <position-value pairs> } is needed.

[muzimuzhi]

but to avoid the second error it seems \intarray_const:Nnn <intarray var> {<size>} { <position-value pairs> } is needed.

Or we can wrap relevant lines in between \debug_suspend: and \debug_resume:, like how \coffin_new:N does.

latex3/l3kernel/l3coffins.dtx

Lines 641 to 658 in 35b15d8

	% \begin{macro}{\coffin_new:N, \coffin_new:c}
	% Creating a new coffin means making the underlying box and adding the
	% data structures. The \cs{debug_suspend:} and \cs{debug_resume:} functions
	% prevent \cs{prop_gclear_new:c} from writing useless information to
	% the log file.
	% \begin{macrocode}
	\cs_new_protected:Npn \coffin_new:N #1
	{
	\box_new:N #1
	\debug_suspend:
	\prop_gclear_new:c { coffin ~ \@@_to_value:N #1 ~ corners }
	\prop_gclear_new:c { coffin ~ \@@_to_value:N #1 ~ poles }
	\prop_gset_eq:cN { coffin ~ \@@_to_value:N #1 ~ corners }
	\c_@@_corners_prop
	\prop_gset_eq:cN { coffin ~ \@@_to_value:N #1 ~ poles }
	\c_@@_poles_prop
	\debug_resume:
	}