[latex3-commits] [git/LaTeX3-latex3-latex3] scan-quark: Avoid using \tl_if_empty:nTF in l3quark since it is not available yet (44c1f68ac)

[Bruno Le Floch]

Repository : https://github.com/latex3/latex3
On branch  : scan-quark
Link       : https://github.com/latex3/latex3/commit/44c1f68ac9874df8313c55e71dbbfa1be2bf4f5e

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

commit 44c1f68ac9874df8313c55e71dbbfa1be2bf4f5e
Author: Bruno Le Floch <bruno at le-floch.fr>
Date:   Wed May 6 23:40:08 2020 +0200

    Avoid using \tl_if_empty:nTF in l3quark since it is not available yet


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

44c1f68ac9874df8313c55e71dbbfa1be2bf4f5e
 l3kernel/l3quark.dtx | 46 +++++++++++++++++++++++++++++-----------------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/l3kernel/l3quark.dtx b/l3kernel/l3quark.dtx
index 4cc9442c7..35d88c7d8 100644
--- a/l3kernel/l3quark.dtx
+++ b/l3kernel/l3quark.dtx
@@ -627,6 +627,10 @@
 %     \item[N] gives an analogue of \cs[no-index]{quark_if_nil:N(TF)}
 %   \end{description}
 %   Any other signature causes an error, as does a function without signature.
+%   We use low-level emptiness tests as \pkg{l3tl} is not available yet when these
+%   functions are used; thankfully we only care about whether strings
+%   are empty so a simple \cs{if_meaning:w} \cs{q_nil} \meta{string}
+%   \cs{q_nil} suffices.
 %
 % \begin{macro}{\@@_new_test:NNNn, \@@_new_test:Nccn,
 %   \@@_new_test_aux:nnNNnnnn, \@@_new_test_choose:nNnnnn}
@@ -635,12 +639,12 @@
   { \@@_new_test_aux:Nx #1 { \@@_module_name:N #1 } }
 \cs_new_protected:Npn \@@_new_test_aux:Nn #1 #2
   {
-    \tl_if_empty:nTF {#2}
-      { \__kernel_msg_expandable_error:nn { kernel } { invalid-quark-function } }
-      {
-        \@@_new_test:Nccn #1
-          { q__#2_recursion_tail } { q__#2_recursion_stop } { __#2 }
-      }
+    \if_meaning:w \q_nil #2 \q_nil
+      \__kernel_msg_expandable_error:nn { kernel } { invalid-quark-function }
+    \else:
+      \@@_new_test:Nccn #1
+        { q__#2_recursion_tail } { q__#2_recursion_stop } { __#2 }
+    \fi:
   }
 \cs_generate_variant:Nn \@@_new_test_aux:Nn { Nx }
 \cs_new_protected:Npn \@@_new_test:NNNn #1
@@ -658,14 +662,18 @@
   }
 \cs_new_protected:Npn \@@_new_conditional:Nnnn #1#2#3#4
   {
-    \tl_if_empty:nTF {#3} { \use_i:nn } { \tl_if_empty:nTF {#2} }
-      { \__kernel_msg_error:nn { kernel } { invalid-quark-function } }
-      {
+    \if_meaning:w \q_nil #2 \q_nil
+      \__kernel_msg_error:nn { kernel } { invalid-quark-function }
+    \else:
+      \if_meaning:w \q_nil #3 \q_nil
+        \__kernel_msg_error:nn { kernel } { invalid-quark-function }
+      \else:
         \exp_last_unbraced:Nf \@@_new_test_aux:nnNNnnnn
           { \cs_split_function:N #1 }
           #1 { conditional }
           {#2} {#3} {#4}
-      }
+      \fi:
+    \fi:
   }
 \cs_generate_variant:Nn \@@_new_conditional:Nnnn { Nxx }
 \cs_new_protected:Npn \@@_new_test_aux:nnNNnnnn #1 #2 #3 #4
@@ -875,7 +883,9 @@
 %   found the result is an empty string.  The approach is to first cut
 %   off everything after the (first) |:| if any is present, then
 %   repeatedly grab |_|-delimited words until finding one of length at
-%   least~$2$.  If no \meta{module} is found (such as in \cs{::n}) we
+%   least~$2$ (we use low-level tests as \pkg{l3tl} is not fully
+%   available when \cs{__kernel_quark_new_test:N} is first used.
+%   If no \meta{module} is found (such as in \cs{::n}) we
 %   get the trailing marker \cs{use_none:n} |{}|, which expands to
 %   nothing.
 %    \begin{macrocode}
@@ -890,13 +900,15 @@
       { \@@_module_name_loop:w ##1 #2 \use_none:n { } #2 \s_@@ }
     \cs_new:Npn \@@_module_name_loop:w ##1 #2
       {
-        \tl_if_empty:nTF {##1} { \@@_module_name_loop:w }
-          {
-            \tl_if_single:nTF {##1} { \@@_module_name_loop:w }
-              { ##1 \@@_module_name_end:w }
-          }
+        \use_i_ii:nnn \if_meaning:w \prg_do_nothing:
+            ##1 \prg_do_nothing: \prg_do_nothing:
+          \exp_after:wN \@@_module_name_loop:w
+        \else:
+          \@@_module_name_end:w ##1
+        \fi:
       }
-    \cs_new:Npn \@@_module_name_end:w ##1 \s_@@ { }
+    \cs_new:Npn \@@_module_name_end:w
+      ##1 \fi: ##2 \s_@@ { \fi: ##1 }
   }
 \exp_after:wN \@@_tmp:w \tl_to_str:n { : _ }
 %    \end{macrocode}