1 files changed, 21 insertions, 10 deletions
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx
index 3237dc3aaa4..10eea3278f4 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx
@@ -547,13 +547,24 @@
 \cs_new:Npn \seq_format:Nn #1#2
   {
     \tl_to_str:f
-      { \@@_seq:of {#1} { \@@_parse:n {#2} } }
+      {
+        \@@_seq:ff { \exp_after:wN \@@_seq_extract:w #1 }
+          { \@@_parse:n {#2} }
+      }
   }
 \cs_generate_variant:Nn \seq_format:Nn { c }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_seq:nn, \@@_seq:of}
+% \begin{macro}[aux, rEXP]{\@@_seq_extract:w}
+%   Extract the contents of a sequence as items of the form
+%   |\__seq_item:n| \Arg{item}.
+%    \begin{macrocode}
+\cs_new:Npn \@@_seq_extract:w \s__seq #1 \s_obj_end { \exp_stop_f: #1 }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[aux, EXP]{\@@_seq:nn, \@@_seq:ff}
 %   The first argument is the contents of a \texttt{seq} variable.  The
 %   second is a parsed \meta{format specification}.  Set up the loop.
 %    \begin{macrocode}
@@ -563,7 +574,7 @@
       #1
       { ? \@@_seq_end:w } { }
   }
-\cs_generate_variant:Nn \@@_seq:nn { of }
+\cs_generate_variant:Nn \@@_seq:nn { ff }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -644,7 +655,7 @@
     \int_compare:nNnTF {#7} < \c_zero
       { \@@_put:nw { - } }
       {
-        \str_case:nnn {#3}
+        \str_case:nnF {#3}
           {
             { ~ } { \@@_put:ow { \c_catcode_other_space_tl } }
             { + } { \@@_put:nw { + } }
@@ -657,7 +668,7 @@
         \__msg_kernel_expandable_error:nnnn
           { str } { invalid-precision-format } {#5} {int}
       }
-    \str_case:nnn {#6}
+    \str_case:nnF {#6}
       {
         { ? } { \@@_int:NwnnNNn \use:n }
         { d } { \@@_int:NwnnNNn \use:n }
@@ -757,7 +768,7 @@
     \token_if_eq_meaning:NNTF 2 #8
       { \@@_put:nw { - } }
       {
-        \str_case:nnn {#3}
+        \str_case:nnF {#3}
           {
             { ~ } { \@@_put:ow { \c_catcode_other_space_tl } }
             { + } { \@@_put:nw { + } }
@@ -768,7 +779,7 @@
     \tl_if_empty:nTF {#5}
       { \@@_put:nw { { 6} } }
       { \@@_put:nw { {#5} } }
-    \str_case:nnn {#6}
+    \str_case:nnF {#6}
       {
         { e } { \@@_fp:wnnnNNw \@@_fp_e:wn }
         { f } { \@@_fp:wnnnNNw \@@_fp_f:wn }
@@ -828,7 +839,7 @@
     \group_end:
     \cs_new:Npn \@@_fp_e:wn \s__fp \__fp_chk:w #1#2#3 ; #4
       {
-        \int_case:nnn {#1}
+        \int_case:nnF {#1}
           {
             {0} { \use:nf { 0 . } { \prg_replicate:nn {#4} { 0 } } e 0 }
             {2} { inf }
@@ -869,7 +880,7 @@
 %    \begin{macrocode}
 \cs_new:Npn \@@_fp_f:wn \s__fp \__fp_chk:w #1#2#3 ; #4
   {
-    \int_case:nnn {#1}
+    \int_case:nnF {#1}
       {
         {0} { \use:nf { 0 . } { \prg_replicate:nn {#4} { 0 } } }
         {2} { inf }
@@ -907,7 +918,7 @@
 %    \begin{macrocode}
 \cs_new:Npn \@@_fp_g:wn \s__fp \__fp_chk:w #1#2 ; #3
   {
-    \int_case:nnn {#1}
+    \int_case:nnF {#1}
       {
         {0} { 0 }
         {2} { inf }