latex-packages/src/utils/powerset.pysty3

62 lines
1.6 KiB
Text

__HEADER__(Iterate over powerset of clist)
\ExplSyntaxOn
%%% Iterate over powerset of claist
\clist_new:N \l_powerset_copied_clist
\seq_new:N \l_powerset_saved_seq
\cs_generate_variant:Nn \clist_remove_all:Nn { N V }
% Pseudocode of this macro
% remove left -> push on stack
% call recursive
% add left to 'extra'
% call recursive
% remove left from 'extra'
% add from stack to left
\cs_new:Npn \__powerset_clist_foreach_aux:Nn #1 #2
{
\clist_if_empty:NTF \l_powerset_copied_clist
{
#2
}
{
\clist_get:NN \l_powerset_copied_clist \l_tmpa_tl
\seq_push:NV \l_powerset_saved_seq \l_tmpa_tl
\clist_pop:NN \l_powerset_copied_clist { \l_tmpa_tl }
\__powerset_clist_foreach_aux:Nn #1 {#2}
\seq_get:NN \l_powerset_saved_seq \l_tmpa_tl
\clist_put_left:NV #1 \l_tmpa_tl
\__powerset_clist_foreach_aux:Nn #1 {#2}
\seq_get:NN \l_powerset_saved_seq \l_tmpa_tl
\clist_remove_all:NV #1 \l_tmpa_tl
\clist_push:NV \l_powerset_copied_clist \l_tmpa_tl
\seq_pop:NN \l_powerset_saved_seq \l_tmpa_tl
}
}
% Usage:
% \clist_use_powerset:Nn {clist variable name}{code for each subset}
% This will execute #2 for each subset of the listname given as #1
% In #2, the name given as #1 can be used for the current subset
% After execution, the value of #1 is restored
\cs_new:Npn \powerset_clist_foreach:Nn #1 #2
{
\clist_set_eq:NN \l_powerset_copied_clist #1
\clist_clear:N #1
\clist_remove_duplicates:N \l_powerset_copied_clist
\__powerset_clist_foreach_aux:Nn #1 {#2}
\clist_set_eq:NN #1 \l_powerset_copied_clist
}