[latex3-commits] [git/LaTeX3-latex3-latex3] l3bitset-2: rewrite bitset_item to take a name (77a51571f)

[Ulrike Fischer]

Repository : https://github.com/latex3/latex3
On branch  : l3bitset-2
Link       : https://github.com/latex3/latex3/commit/77a51571f6f40238e7b42683e4ef7ec1c628538e

>---------------------------------------------------------------

commit 77a51571f6f40238e7b42683e4ef7ec1c628538e
Author: Ulrike Fischer <fischer at troubleshooting-tex.de>
Date:   Tue Dec 29 16:06:09 2020 +0100

    rewrite bitset_item to take a name


>---------------------------------------------------------------

77a51571f6f40238e7b42683e4ef7ec1c628538e
 l3experimental/l3bitset/l3bitset.dtx | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/l3experimental/l3bitset/l3bitset.dtx b/l3experimental/l3bitset/l3bitset.dtx
index c04f3dc05..fb24ef4b2 100644
--- a/l3experimental/l3bitset/l3bitset.dtx
+++ b/l3experimental/l3bitset/l3bitset.dtx
@@ -150,7 +150,7 @@
 %
 % \section{Setting and unsetting bits}
 %
-% \begin{function}[added = 2020-12-13]
+% \begin{function}[added = 2020-12-13, updated=2020-12-29]
 %   { \bitset_set_true:Nn, \bitset_set_true:cn, \bitset_gset_true:Nn, \bitset_gset_true:cn  }
 %   \begin{syntax}
 %     \cs{bitset_set_true:Nn}   \meta{bitset var}  \Arg{position}\\
@@ -164,7 +164,7 @@
 % If needed the length of the bit vector is enlarged.
 % \end{function}
 %
-% \begin{function}[added = 2020-12-13]
+% \begin{function}[added = 2020-12-13,updated=2020-12-29]
 %   { \bitset_set_false:Nn, \bitset_set_false:cn, \bitset_gset_false:Nn, \bitset_set_false:cn }
 %   \begin{syntax}
 %     \cs{bitset_set_false:Nn}   \meta{bitset var}  \Arg{position}\\
@@ -193,13 +193,14 @@
 %
 % \section{Using bitsets}
 %
-% \begin{function}[EXP,added = 2020-12-14]
+% \begin{function}[EXP,added = 2020-12-14, updated=2020-12-29]
 %   { \bitset_item:Nn, \bitset_item:cn }
 %   \begin{syntax}
-%     \cs{bitset_item:Nn}   \meta{bitset var}  \Arg{integer expression}
+%     \cs{bitset_item:Nn}   \meta{bitset var}  \Arg{position}
 %   \end{syntax}
-% Evaluates the \meta{integer expression} and output \texttt{1} if the bit with
-% this index number is set and \texttt{0} otherwise.
+% \cs{bitset_item:Nn} outputs \texttt{1} if the bit with
+% the index number represented by \Arg{position} is set and \texttt{0} otherwise.
+%  \Arg{position} is a declared name or a positiv, unsigned explicit number.
 % \end{function}
 %
 % \begin{function}[EXP,added = 2020-12-13]
@@ -667,16 +668,23 @@
 %   {
 %     \bitset_item:Nn, \bitset_item:cn
 %   }
+% All bits that have been set at anytime have an entry in the prop,
+% so we can take everything else as 0.
 %    \begin{macrocode}
 \cs_new:Npn \bitset_item:Nn #1 #2
   {
-    \int_compare:nNnTF { #2 } > { 0 }
-      {
-        \int_eval:n { \str_item:Nn #1 { 0 - (#2)} + 0 }
-      }
+    \prop_if_in:cnTF { g_@@_\cs_to_str:N #1 _key_prop } {#2}
       {
-        0
-      }
+        \int_eval:n
+          {
+            \str_item:Nn #1
+              { 0 - ( \prop_item:cn { g_@@_\cs_to_str:N #1 _key_prop }{#2} ) }
+            +0
+          }
+     }
+     {
+       0
+     }
   }
 \cs_generate_variant:Nn \bitset_item:Nn {cn}
 %    \end{macrocode}