mh/xfrac 0.3 (2feb10)

git-svn-id: svn://tug.org/texlive/trunk@16903 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 350 insertions, 192 deletions

diff --git a/Master/texmf-dist/tex/latex/mh/xfrac.sty b/Master/texmf-dist/tex/latex/mh/xfrac.sty
index f5d92e5b979..1a6d0ff7d60 100644
--- a/Master/texmf-dist/tex/latex/mh/xfrac.sty
+++ b/Master/texmf-dist/tex/latex/mh/xfrac.sty
@@ -8,15 +8,13 @@
 %% 
 %% This is a generated file.
 %% 
-%% Copyright (C) 2004, 2008, 2009 by Morten Hoegholm <mh.ctan@gmail.com>
+%% Copyright (C) 2004, 2008-2010 by Morten Hoegholm <mh.ctan@gmail.com>
 %% 
 %% This work may be distributed and/or modified under the
 %% conditions of the LaTeX Project Public License, either
-%% version 1.3 of this license or (at your option) any later
+%% version 1.3c of this license or (at your option) any later
 %% version. The latest version of this license is in
 %%    http://www.latex-project.org/lppl.txt
-%% and version 1.3 or later is part of all distributions of
-%% LaTeX version 2005/12/01 or later.
 %% 
 %% This work has the LPPL maintenance status "maintained".
 %% 
@@ -27,214 +25,374 @@
 %%    xfrac.sty, xfrac.pdf, xfrac.ins, xfrac.drv.
 %% 
 \RequirePackage{expl3}[2009/08/05]
-\ProvidesExplPackage{xfrac}{2009/08/10}{0.2a}{Text fractions}
-\RequirePackage{textcomp,graphicx,amstext}
-\RequirePackage{template}[2008/08/03]
-\RequirePackage{xparse}[2008/08/03]
-\bool_new:N \g_cm_recommended_bool
-\DeclareOption{cm-recommended}
-              { \bool_gset_true:N \g_cm_recommended_bool }
-\DeclareOption{cm-standard}
-              { \bool_gset_false:N \g_cm_recommended_bool }
-\ExecuteOptions{cm-recommended}
-\ProcessOptions\relax
-\box_new:N \l_xfrac_temp_box
+\ProvidesExplPackage{xfrac}{2010/02/02}{0.3}{Text fractions}
+\RequirePackage { amstext , graphicx , l3keys2e , textcomp , xtemplate }
+\keys_define:nn { xfrac } {
+  cm-recommended .choice:,
+  cm-recommended /
+    false        .code:n     =
+      { \bool_set_true:N \l_xfrac_cm_std_bool },
+  cm-recommended /
+    true         .code:n     =
+      { \bool_set_false:N \l_xfrac_cm_std_bool },
+  cm-recommended .default:n  = { true },
+  cm-standard    .bool_set:N = \l_xfrac_cm_std_bool
+}
+\ProcessKeysOptions { xfrac }
 \box_new:N \l_xfrac_slash_box
-\DeclareTemplateType{xfrac}{3}
-\DeclareTemplate{xfrac}{text}{3}{
-  numerator-font      = n  [\f@family]  \xfrac_numeratorfont:,
-  numerator-format    = f1 [#1]         \xfrac_numeratorformat:n,
-  slash-symbol        = n  [\textfractionsolidus]
-                                        \xfrac_slashsymbol:,
-  slash-symbol-font   = n  [\f@family]  \xfrac_slashsymbolfont:,
-  slash-symbol-format = f1 [#1]         \xfrac_slashsymbolformat:n,
-  denominator-font    = n  [\f@family]  \xfrac_denominatorfont:,
-  denominator-format  = f1 [#1]         \xfrac_denominatorformat:n,
-  h-scale             = n  [1]          \xfrac_hscale:,
-  v-scale             = n  [1]          \xfrac_vscale:,
-  scale-factor        = n  [.83333]     \xfrac_scalefactor:,
-  scale-relative      = s  [true]
-    { \cs_set:Npn \xfrac_relscale: {\box_ht:N\l_xfrac_slash_box}}
-    { \cs_set:Npn \xfrac_relscale: {
-      \dim_eval:n { \box_ht:N\l_xfrac_temp_box + \box_dp:N\l_xfrac_temp_box }} },
-  scaling             = s  [true]
-    {\cs_set:Npn\xfrac_fontscale: {
-       \fontsize{\xfrac_scalefactor: \xfrac_relscale:}{\c_zero_dim}\selectfont}}
-    { \cs_set_eq:NN \xfrac_fontscale: \prg_do_nothing: },
-  numerator-top-sep   = L  [\c_max_dim]  \l_xfrac_numeratortopsep_fdim,
-  numerator-bot-sep   = L  [\c_max_dim]  \l_xfrac_numeratorbotsep_fdim,
-  denominator-bot-sep = L  [\c_max_dim]  \l_xfrac_denominatorbotsep_fdim,
-  slash-right-kern    = L  [0pt]        \l_xfrac_slashrightsep_fdim,
-  slash-left-kern     = L  [0pt]        \l_xfrac_slashleftsep_fdim,
-  slash-right-mkern   = n  [-2mu]       \l_xfrac_slashrightmsep_fmu,
-  slash-left-mkern    = n  [-1mu]       \l_xfrac_slashleftmsep_fmu,
-  math-mode           = s  [false] { \cs_set_eq:NN \xfrac_math: \ensuremath }
-                                   { \cs_set_eq:NN \xfrac_math: \use:n },
-  phantom             = n  [8]          \xfrac_phantom:,
-}{
-  \DoParameterAssignments
-  \mode_if_math:TF{
-    \cs_set_eq:NN \xfrac_textormath: \text
-    \cs_set:Npx \xfrac_slashfontchange: {\tex_fam:D \xfrac_slashsymbolfont: }
-    \cs_set:Npx \xfrac_numeratorfontchange: {\tex_fam:D \xfrac_numeratorfont: }
-    \cs_set:Npx \xfrac_denominatorfontchange: {\tex_fam:D \xfrac_denominatorfont: }
-  }{
-    \cs_set_eq:NN \xfrac_textormath: \mbox
-    \cs_set:Npn\xfrac_slashfontchange: {
-      \fontfamily{\xfrac_slashsymbolfont: }\selectfont}
-    \cs_set:Npn\xfrac_numeratorfontchange: {
-      \fontfamily{\xfrac_numeratorfont: }\selectfont}
-    \cs_set:Npn\xfrac_denominatorfontchange: {
-      \fontfamily{\xfrac_denominatorfont: }\selectfont}
+\box_new:N \l_xfrac_tmp_box
+\cs_new:Npn \xfrac_tmp:w { }
+\dim_new:N \l_xfrac_denominator_bot_sep_dim
+\dim_new:N \l_xfrac_numerator_bot_sep_dim
+\dim_new:N \l_xfrac_numerator_top_sep_dim
+\dim_new:N \l_xfrac_slash_left_sep_dim
+\dim_new:N \l_xfrac_slash_right_sep_dim
+\tl_new:N \l_xfrac_denominator_font_tl
+\tl_new:N \l_xfrac_hscale_tl
+\tl_new:N \l_xfrac_numerator_font_tl
+\tl_new:N \l_xfrac_phantom_tl
+\tl_new:N \l_xfrac_scale_factor_tl
+\tl_new:N \l_xfrac_slash_left_msep_tl
+\tl_new:N \l_xfrac_slash_right_msep_tl
+\tl_new:N \l_xfrac_slash_symbol_tl
+\tl_new:N \l_xfrac_slash_symbol_font_tl
+\tl_new:N \l_xfrac_vscale_tl
+\cs_new_nopar:Npn \xfrac_fontscale:
+\cs_new:Npn \xfrac_math:n #1 { }
+\cs_new_nopar:Npn \xfrac_denominator_font_change: { }
+\cs_new:Npn \xfrac_denominator_format:n #1 { }
+\cs_new_nopar:Npn \xfrac_numerator_font_change: { }
+\cs_new:Npn \xfrac_numerator_format:n #1 { }
+\cs_new_nopar:Npn \xfrac_relscale: { }
+\cs_new_nopar:Npn \xfrac_slash_symbol_font_change: { }
+\cs_new:Npn \xfrac_slash_symbol_format:n #1 { }
+\cs_new:Npn \xfrac_text_or_math:n #1 { }
+\DeclareObjectType { xfrac } { 3 }
+\DeclareTemplateInterface { xfrac } { text } { 3 } {
+  denominator-bot-sep : length     = \c_max_dim           ,
+  denominator-font    : tokenlist  = \f@family            ,
+  denominator-format  : function 1 = #1                   ,
+  h-scale             : tokenlist  = 1                    ,
+  math-mode           : choice { false , true }
+                                   = false                ,
+  numerator-font      : tokenlist  = \f@family            ,
+  numerator-format    : function 1 = #1                   ,
+  numerator-bot-sep   : length     = \c_max_dim           ,
+  numerator-top-sep   : length     = \c_max_dim           ,
+  phantom             : tokenlist  = 8                    ,
+  scale-factor        : tokenlist  = 0.83333              ,
+  scale-relative      : choice { false , true }
+                                   = true                 ,
+  scaling             : choice { false , true }
+                                   = true                 ,
+  slash-left-kern     : length     = 0 pt                 ,
+  slash-left-mkern    : tokenlist  = -2 mu                ,
+  slash-right-kern    : length     = 0 pt                 ,
+  slash-right-mkern   : tokenlist  = -1 mu                ,
+  slash-symbol        : tokenlist  = \textfractionsolidus ,
+  slash-symbol-font   : tokenlist  = \f@family            ,
+  slash-symbol-format : function 1 = #1                   ,
+  v-scale             : tokenlist  = 1                    ,
+}
+\DeclareTemplateCode { xfrac } { text } { 3 }
+  {
+    denominator-bot-sep = \l_xfrac_denominator_bot_sep_dim ,
+    denominator-font    = \l_xfrac_denominator_font_tl     ,
+    denominator-format  = \xfrac_denominator_format:n      ,
+    h-scale             = \l_xfrac_hscale_tl               ,
+    math-mode           =
+      {
+        false = \cs_set_eq:NN \xfrac_math:n \use:n,
+        true  = \cs_set_eq:NN \xfrac_math:n \ensuremath
+      },
+    numerator-font      = \l_xfrac_numerator_font_tl       ,
+    numerator-format    = \xfrac_numerator_format:n        ,
+    numerator-bot-sep   = \l_xfrac_numerator_bot_sep_dim   ,
+    numerator-top-sep   = \l_xfrac_numerator_top_sep_dim   ,
+    phantom             = \l_xfrac_phantom_tl              ,
+    scale-factor        = \l_xfrac_scale_factor_tl         ,
+    scale-relative      =
+      {
+        false =
+          \cs_set_nopar:Npn \xfrac_relscale:
+            {
+              \dim_eval:n
+                {
+                    \box_ht:N \l_xfrac_tmp_box
+                  + \box_dp:N \l_xfrac_tmp_box
+                }
+            },
+        true  =
+          \cs_set_nopar:Npn \xfrac_relscale:
+            { \box_ht:N \l_xfrac_slash_box }
+      },
+    scaling             =
+      {
+        false = \cs_set_eq:NN \xfrac_fontscale: \prg_do_nothing:,
+        true  =
+          \cs_set_nopar:Npn \xfrac_fontscale:
+            {
+              \fontsize { \l_xfrac_scale_factor_tl \xfrac_relscale: }
+                { \c_zero_dim }
+              \selectfont
+            }
+      },
+    slash-left-kern     = \l_xfrac_slash_left_sep_dim      ,
+    slash-left-mkern    = \l_xfrac_slash_left_msep_tl      ,
+    slash-right-kern    = \l_xfrac_slash_right_sep_dim     ,
+    slash-right-mkern   = \l_xfrac_slash_right_msep_tl     ,
+    slash-symbol        = \l_xfrac_slash_symbol_tl         ,
+    slash-symbol-font   = \l_xfrac_slash_symbol_font_tl    ,
+    slash-symbol-format = \xfrac_slash_symbol_format:n     ,
+    v-scale             = \l_xfrac_vscale_tl
   }
-  \xfrac_textormath: {
-    \m@th
-    \sbox\l_xfrac_temp_box {\xfrac_math: {\vphantom{(}}}
-    \sbox\l_xfrac_slash_box {
-      \xfrac_math: {
-        \xfrac_slashsymbolformat:n {
-          \xfrac_math: {
-            \xfrac_slashfontchange:
-              \IfValueTF{#2}{#2}{\xfrac_slashsymbol: }
-          }
-        }
-      }
-    }
-    \dim_compare:nNnTF \l_xfrac_numeratortopsep_fdim = \c_max_dim
-    {
-      \dim_compare:nNnTF \l_xfrac_numeratorbotsep_fdim = \c_max_dim
+  {
+    \AssignTemplateKeys
+    \mode_if_math:TF
       {
-        \cs_set:Npn\xfrac_next: {\raisebox{\box_ht:N\l_xfrac_slash_box
-                                  -\box_dp:N\l_xfrac_slash_box-\height}}
-      }{
-        \cs_set:Npn\xfrac_next: {\raisebox{\l_xfrac_numeratorbotsep_fdim }}
+        \cs_set_eq:NN \xfrac_text_or_math:n \text
+        \cs_set_nopar:Npx \xfrac_denominator_font_change:
+          { \tex_fam:D \l_xfrac_denominator_font_tl }
+        \cs_set_nopar:Npx \xfrac_numerator_font_change:
+          { \tex_fam:D \l_xfrac_numerator_font_tl }
+        \cs_set_nopar:Npx \xfrac_slash_symbol_font_change:
+          { \tex_fam:D \l_xfrac_slash_symbol_font_tl }
       }
-    }
-    {
-      \dim_compare:nNnTF \l_xfrac_numeratorbotsep_fdim = \c_max_dim
       {
-        \cs_set:Npn\xfrac_next: {
-          \raisebox{
-            \box_ht:N\l_xfrac_slash_box - \l_xfrac_numeratortopsep_fdim
-            - \height
+        \cs_set_eq:NN \xfrac_text_or_math:n \mbox
+        \cs_set_nopar:Npn \xfrac_denominator_font_change:
+          {
+            \fontfamily { \l_xfrac_denominator_font_tl }
+            \selectfont
+          }
+        \cs_set_nopar:Npn \xfrac_numerator_font_change:
+          {
+            \fontfamily { \l_xfrac_numerator_font_tl }
+            \selectfont
+          }
+        \cs_set_nopar:Npn \xfrac_slash_symbol_font_change:
+          {
+            \fontfamily { \l_xfrac_slash_symbol_font_tl }
+            \selectfont
           }
-        }
       }
+    \xfrac_text_or_math:n
       {
-        \PackageError{xfrac}
-          {You~ have~ specified~ both~ numerator-top-sep~ and~
-          numerator-bot-sep}
-          {I~ will~ pretend~ you~ didn't~ specify~ any~ of ~them}
-        \cs_set:Npn\xfrac_next: {\raisebox{\box_ht:N\l_xfrac_slash_box
-                                  -\box_dp:N\l_xfrac_slash_box-\height}}
-      }
-    }
-    \xfrac_next: {
-      \xfrac_fontscale:
-      \xfrac_numeratorformat:n {
-        \scalebox{\xfrac_hscale: }[\xfrac_vscale: ]
-          { \xfrac_math:{ \xfrac_numeratorfontchange:
-                          {\vphantom{\xfrac_phantom: }#1} } }
-      }
-    }
-    \xfrac_math: { % THIS IS JUST WRONG!
-      \mode_if_math:TF {  \mskip \l_xfrac_slashrightmsep_fmu }
-                       {\hskip \l_xfrac_slashrightsep_fdim}
-      }
-    \usebox\l_xfrac_slash_box
-    \xfrac_math: {
-      \mode_if_math:TF {
-        \mskip \l_xfrac_slashleftmsep_fmu
-      }{
-        \hskip \l_xfrac_slashleftsep_fdim
-      } }
-    \dim_compare:nNnTF \l_xfrac_denominatorbotsep_fdim=\c_max_dim
-    {  \raisebox{-\box_dp:N \l_xfrac_slash_box} }
-    {
-     \raisebox{\l_xfrac_denominatorbotsep_fdim}
-    }
-    {
-      \xfrac_fontscale:
-      \xfrac_denominatorformat:n {
-        \scalebox{\xfrac_hscale:}[\xfrac_vscale:]
-          { \xfrac_math: { \xfrac_denominatorfontchange:
-                          {\vphantom{\xfrac_phantom: }#3} } }
+        \m@th
+        \hbox_set:Nn \l_xfrac_tmp_box
+          { \xfrac_math:n { \vphantom { ( ) } } }
+        \hbox_set:Nn \l_xfrac_slash_box
+          {
+            \xfrac_math:n
+              {
+                \xfrac_slash_symbol_format:n
+                  {
+                    \xfrac_math:n
+                      {
+                        \xfrac_slash_symbol_font_change:
+                        \IfNoValueTF {#2}
+                          { \l_xfrac_slash_symbol_tl } {#2}
+                      }
+                  }
+              }
+          }
+        \cs_set_nopar:Npn \xfrac_tmp:w
+          {
+            \raisebox
+              {
+                  \box_ht:N \l_xfrac_slash_box
+                - \box_dp:N \l_xfrac_slash_box
+                - \height
+              }
+          }
+        \dim_compare:nNnTF
+          { \l_xfrac_numerator_top_sep_dim } = { \c_max_dim }
+          {
+            \dim_compare:nNnF
+              { \l_xfrac_numerator_bot_sep_dim } = { \c_max_dim }
+              {
+                \cs_set_nopar:Npn \xfrac_tmp:w
+                  {
+                    \raisebox
+                      { \dim_use:N \l_xfrac_numerator_bot_sep_dim }
+                  }
+              }
+          }
+          {
+            \dim_compare:nNnTF
+              { \l_xfrac_numerator_bot_sep_dim } = { \c_max_dim }
+                {
+                  \cs_set_nopar:Npn \xfrac_tmp:w
+                    {
+                      \raisebox
+                        {
+                            \box_ht:N \l_xfrac_slash_box
+                          - \dim_use:N \l_xfrac_numerator_top_sep_dim
+                          - \height
+                        }
+                    }
+                }
+                {
+                  \msg_error:nn { xfrac }
+                    { over-specified-numerator-sep }
+                }
+          }
+        \xfrac_tmp:w
+          {
+            \xfrac_fontscale:
+            \xfrac_numerator_format:n
+              {
+                \scalebox { \l_xfrac_hscale_tl } [ \l_xfrac_vscale_tl ]
+                  {
+                    \xfrac_math:n
+                      {
+                        \xfrac_numerator_font_change:
+                        {
+                          \vphantom { \l_xfrac_phantom_tl }
+                          #1
+                        }
+                      }
+                  }
+              }
+          }
+        \xfrac_math:n
+          { % THIS IS JUST WRONG!
+            \mode_if_math:TF
+              { \tex_mskip:D \l_xfrac_slash_right_msep_tl }
+              { \tex_hskip:D \l_xfrac_slash_right_sep_dim }
+          }
+        \box_use:N \l_xfrac_slash_box
+        \xfrac_math:n
+          {
+            \mode_if_math:TF
+              { \tex_mskip:D \l_xfrac_slash_left_msep_tl }
+              { \tex_hskip:D \l_xfrac_slash_left_sep_dim }
+          }
+        \dim_compare:nNnTF
+          { \l_xfrac_denominator_bot_sep_dim } = { \c_max_dim }
+          {
+            \cs_set_nopar:Npn \xfrac_tmp:w
+              { \raisebox { - \box_dp:N \l_xfrac_slash_box } }
+          }
+          {
+            \cs_set_nopar:Npn \xfrac_tmp:w
+              {
+                \raisebox
+                  { \dim_use:N \l_xfrac_denominator_bot_sep_dim }
+              }
+          }
+        \xfrac_tmp:w
+          {
+            \xfrac_fontscale:
+            \xfrac_denominator_format:n
+              {
+                \scalebox { \l_xfrac_hscale_tl } [ \l_xfrac_vscale_tl ]
+                  {
+                    \xfrac_math:n
+                      {
+                        \xfrac_denominator_font_change:
+                        {
+                          \vphantom { \l_xfrac_phantom_tl }
+                          #3
+                        }
+                      }
+                  }
+              }
+          }
       }
-    }
   }
+\DeclareRestrictedTemplate { xfrac } { text } { math } {
+  numerator-font      = \number \fam ,
+  slash-symbol        = /            ,
+  slash-symbol-font   = \number \fam ,
+  denominator-font    = \number \fam ,
+  scale-factor        = 0.7          ,
+  scale-relative      = false        ,
+  scaling             = true         ,
+  numerator-top-sep   = 0 pt         ,
+  denominator-bot-sep = 0 pt         ,
+  math-mode           = true         ,
+  phantom             = (
 }
-\DeclareRestrictedTemplate{xfrac}{math}{text}{
-  numerator-font      = \number\fam,
-  slash-symbol        = /,
-  slash-symbol-font   = \number\fam,
-  denominator-font    = \number\fam,
-  scale-factor        = 0.7,
-  scale-relative      = false,
-  scaling             = true,
-  numerator-top-sep   = 0pt,
-  denominator-bot-sep = 0pt,
-  math-mode           = true,
-  phantom             = (,
-}
-\DeclareInstance{xfrac}{default}{text}{ }
-\DeclareInstance{xfrac}{mathdefault}{math}{ }
-\DeclareCollectionInstance{plainmath}{xfrac}{mathdefault}{math}{
-  denominator-bot-sep=0pt,
-  numerator-bot-sep=0pt,
-  numerator-top-sep=\c_max_dim,
-  scale-factor = 1,
-  scale-relative = false,
-  scaling = true,
-  slash-right-mkern=0mu,
-  slash-left-mkern=0mu,
+\DeclareInstance { xfrac } { default } { text } { }
+\DeclareInstance { xfrac } { mathdefault } { math } { }
+\DeclareCollectionInstance { plainmath } { xfrac } { mathdefault }
+  { math }{
+  denominator-bot-sep = 0 pt       ,
+  numerator-bot-sep   = 0 pt       ,
+  numerator-top-sep   = \c_max_dim ,
+  scale-factor        = 1          ,
+  scale-relative      = false      ,
+  scaling             = true       ,
+  slash-right-mkern   = 0mu        ,
+  slash-left-mkern    = 0mu
 }
-\DeclareInstance{xfrac}{cmr}{text}{
-  denominator-bot-sep=0pt,
-  numerator-top-sep=\DelayEvaluation{.2ex},
-  slash-left-kern=\DelayEvaluation{-.1em},
-  slash-right-kern=\DelayEvaluation{-.1em},
+\DeclareInstance { xfrac } { cmr } { text } {
+  denominator-bot-sep = 0 pt    ,
+  numerator-top-sep   = 0.2 ex  ,
+  slash-left-kern     = -0.1 em ,
+  slash-right-kern    = -0.1 em
 }
-\DeclareInstance{xfrac}{cmss}{text}{
-  denominator-bot-sep=0pt,
-  numerator-top-sep=\DelayEvaluation{.2ex},
-  slash-left-kern=\DelayEvaluation{-.1em},
-  slash-right-kern=\DelayEvaluation{-.1em},
+\DeclareInstance { xfrac } { cmss } { text } {
+  denominator-bot-sep = 0 pt    ,
+  numerator-top-sep   = 0.2 ex  ,
+  slash-left-kern     = -0.1 em ,
+  slash-right-kern    = -0.1 em
 }
-\DeclareInstance{xfrac}{cmtt}{text}{
-  denominator-bot-sep=0pt,
-  numerator-top-sep=\DelayEvaluation{.2ex},
-  slash-left-kern=\DelayEvaluation{-.1em},
-  slash-right-kern=\DelayEvaluation{-.1em},
+\DeclareInstance { xfrac } { cmtt } { text } {
+  denominator-bot-sep = 0 pt    ,
+  numerator-top-sep   = 0.2 ex  ,
+  slash-left-kern     = -0.1 em ,
+  slash-right-kern    = -0.1 em
 }
-\DeclareCollectionInstance{cm-recommended}{xfrac}{cmr}{text}{
-  slash-symbol-font   = ptm,
+\bool_if:NF \l_xfrac_cm_std_bool
+  {
+    \DeclareInstance { xfrac } { cmr } { text }
+      { slash-symbol-font = ptm }
+    \DeclareInstance { xfrac } { cmss } { text }
+      { slash-symbol-font = ptm }
+    \DeclareInstance { xfrac } { cmtt } { text }
+      { slash-symbol-font = ppl }
+  }
+\DeclareInstance { xfrac } { lmr } { text } {
+  denominator-bot-sep = 0 pt     ,
+  numerator-top-sep   = 0.1 ex   ,
+  slash-left-kern     = -0.15 em ,
+  slash-right-kern    = -0.15 em
 }
-\DeclareCollectionInstance{cm-recommended}{xfrac}{cmss}{text}{
-  slash-symbol-font   = ptm,
+\DeclareInstance { xfrac } { lmss } { text } {
+  denominator-bot-sep = 0 pt     ,
+  numerator-top-sep   = 0 pt     ,
+  slash-left-kern     = -0.15 em ,
+  slash-right-kern    = -0.15 em
 }
-\DeclareCollectionInstance{cm-recommended}{xfrac}{cmtt}{text}{
-  slash-symbol-font   = ppl,
+\DeclareInstance { xfrac } { lmtt } { text } {
+  denominator-bot-sep = 0 pt     ,
+  numerator-top-sep   = 0 pt     ,
+  slash-left-kern     = -0.15 em ,
+  slash-right-kern    = -0.15 em
 }
-\bool_if:NT \g_cm_recommended_bool
-               {\UseCollection{xfrac}{cm-recommended}}
-\DeclareDocumentCommand \sfrac {o mom}{
+\msg_new:nnnn { xfrac } { over-specified-numerator-sep }
+  {You have specified both numerator-top-sep and numerator-bot-sep}
+  {I will pretend that you didn't specify either of them}
+\NewDocumentCommand \sfrac { o m o m } {
   \mode_if_math:TF
-{
-    \cs_set:Npx \xfrac_next: {mathfam\number\fam}
-    \IfExistsInstanceTF{xfrac}{\xfrac_next: }
-    {\UseInstance{xfrac}{\xfrac_next: }}
-    {\UseInstance{xfrac}{mathdefault}}
-    {#2}{#3}{#4}
-}
-{
-    \IfExistsInstanceTF{xfrac}{#1}
-    {\UseInstance{xfrac}{#1}{#2}{#3}{#4}}
-    {\IfExistsInstanceTF{xfrac}{\f@family}
-      {\UseInstance{xfrac}{\f@family}}
-      {\UseInstance{xfrac}{default}}
-        {#2}{#3}{#4}
+    {
+      \IfInstanceExistTF { xfrac } { mathfam \number \fam }
+        { \UseInstance { xfrac } { mathfam \number \fam } }
+        { \UseInstance { xfrac } { mathdefault } }
+      {#2} {#3} {#4}
+    }
+    {
+      \IfInstanceExistTF { xfrac } {#1}
+        { \UseInstance { xfrac } {#1} }
+        {
+          \IfInstanceExistTF { xfrac } { \f@family }
+            { \UseInstance { xfrac } { \f@family } }
+            { \UseInstance { xfrac } { default } }
+        }
+      {#2} {#3} {#4}
     }
-  }
 }
 \endinput
 %%