expl3 1407 (9jun09)

git-svn-id: svn://tug.org/texlive/trunk@13686 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 354 insertions, 355 deletions

diff --git a/Master/texmf-dist/tex/latex/expl3/l3token.sty b/Master/texmf-dist/tex/latex/expl3/l3token.sty
index b9f43418038..034312a4707 100644
--- a/Master/texmf-dist/tex/latex/expl3/l3token.sty
+++ b/Master/texmf-dist/tex/latex/expl3/l3token.sty
@@ -15,7 +15,7 @@
 %% Do not distribute a modified version of this file.
 %% 
 %% 
-%% File: l3token.dtx Copyright (C) 2005-2006 LaTeX3 project
+%% File: l3token.dtx Copyright (C) 2005-2009 LaTeX3 project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -33,7 +33,7 @@
 %%
 %% The development version of the bundle can be found at
 %%
-%%    http://www.latex-project.org/cgi-bin/cvsweb.cgi/
+%%    http://www.latex-project.org/svnroot/experimental/trunk/
 %%
 %% for those people who are interested.
 %%
@@ -48,64 +48,108 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3token.dtx 701 2007-11-27 14:21:05Z morten $
+\GetIdInfo$Id: l3token.dtx 1365 2009-05-31 17:26:17Z mittelba $
        {L3 Experimental token investigation and manipulation}
 \ProvidesExplPackage
   {\filename}{\filedate}{\fileversion}{\filedescription}
-\RequirePackage{l3prg}
-\RequirePackage{l3int}
-\let_new:NN \char_set_catcode:w \tex_catcode:D
-\def_new:Npn \char_set_catcode:nn #1#2{
-  \char_set_catcode:w #1 = \int_eval:n{#2}
-}
-\def_new:Npn \char_value_catcode:w {\int_use:N\tex_catcode:D}
-\def_new:Npn \char_value_catcode:n #1{\char_value_catcode:w \int_eval:n{#1}}
-\def_new:Npn \char_show_value_catcode:w {\tex_showthe:D\tex_catcode:D}
-\def_new:Npn \char_show_value_catcode:n #1{
-  \char_show_value_catcode:w \int_eval:n{#1}}
-\let_new:NN \char_set_mathcode:w \tex_mathcode:D
-\def_new:Npn \char_set_mathcode:nn #1#2{
-  \char_set_mathcode:w #1 = \int_eval:n{#2}
-}
-\def_protected_new:Npn \char_gset_mathcode:w {\pref_global:D\tex_mathcode:D}
-\def_new:Npn \char_gset_mathcode:nn #1#2{
-  \char_gset_mathcode:w #1 = \int_eval:n{#2}
-}
-\def_new:Npn \char_value_mathcode:w {\int_use:N\tex_mathcode:D}
-\def_new:Npn \char_value_mathcode:n #1{\char_value_mathcode:w \int_eval:n{#1}}
-\def_new:Npn \char_show_value_mathcode:w {\tex_showthe:D\tex_mathcode:D}
-\def_new:Npn \char_show_value_mathcode:n #1{
-  \char_show_value_mathcode:w \int_eval:n{#1}}
-\let_new:NN \char_set_lccode:w \tex_lccode:D
-\def_new:Npn \char_set_lccode:nn #1#2{
-  \char_set_lccode:w #1 = \int_eval:n{#2}
-}
-\def_new:Npn \char_value_lccode:w {\int_use:N\tex_lccode:D}
-\def_new:Npn \char_value_lccode:n #1{\char_value_lccode:w \int_eval:n{#1}}
-\def_new:Npn \char_show_value_lccode:w {\tex_showthe:D\tex_lccode:D}
-\def_new:Npn \char_show_value_lccode:n #1{
-  \char_show_value_lccode:w \int_eval:n{#1}}
-\let_new:NN \char_set_uccode:w \tex_uccode:D
-\def_new:Npn \char_set_uccode:nn #1#2{
-  \char_set_uccode:w #1 = \int_eval:n{#2}
-}
-\def_new:Npn \char_value_uccode:w {\int_use:N\tex_uccode:D}
-\def_new:Npn \char_value_uccode:n #1{\char_value_uccode:w \int_eval:n{#1}}
-\def_new:Npn \char_show_value_uccode:w {\tex_showthe:D\tex_uccode:D}
-\def_new:Npn \char_show_value_uccode:n #1{
-  \char_show_value_uccode:w \int_eval:n{#1}}
-\let_new:NN \char_set_sfcode:w \tex_sfcode:D
-\def_new:Npn \char_set_sfcode:nn #1#2{
-  \char_set_sfcode:w #1 = \int_eval:n{#2}
-}
-\def_new:Npn \char_value_sfcode:w {\int_use:N\tex_uccode:D}
-\def_new:Npn \char_value_sfcode:n #1{\char_value_sfcode:w \int_eval:n{#1}}
-\def_new:Npn \char_show_value_sfcode:w {\tex_showthe:D\tex_sfcode:D}
-\def_new:Npn \char_show_value_sfcode:n #1{
-  \char_show_value_sfcode:w \int_eval:n{#1}}
-\def_new:Npn \token_new:Nn #1#2{\glet_new:NN #1#2}
-\let_new:NN \c_group_begin_token {
-\let_new:NN \c_group_end_token }
+\package_check_loaded_expl:
+\cs_new_eq:NN \char_set_catcode:w \tex_catcode:D
+\cs_new_nopar:Npn \char_set_catcode:nn #1#2 {
+  \char_set_catcode:w #1 = \intexpr_eval:w #2\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_value_catcode:w { \int_use:N \tex_catcode:D }
+\cs_new_nopar:Npn \char_value_catcode:n #1 {
+  \char_value_catcode:w \intexpr_eval:w #1\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_show_value_catcode:w {
+  \tex_showthe:D \tex_catcode:D
+}
+\cs_new_nopar:Npn \char_show_value_catcode:n #1 {
+  \char_show_value_catcode:w \intexpr_eval:w #1\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_make_escape:N           #1 { \char_set_catcode:nn {`#1} {\c_zero}   }
+\cs_new_nopar:Npn \char_make_begin_group:N      #1 { \char_set_catcode:nn {`#1} {\c_one}    }
+\cs_new_nopar:Npn \char_make_end_group:N        #1 { \char_set_catcode:nn {`#1} {\c_two}    }
+\cs_new_nopar:Npn \char_make_math_shift:N       #1 { \char_set_catcode:nn {`#1} {\c_three}  }
+\cs_new_nopar:Npn \char_make_alignment:N        #1 { \char_set_catcode:nn {`#1} {\c_four}   }
+\cs_new_nopar:Npn \char_make_end_line:N         #1 { \char_set_catcode:nn {`#1} {\c_five}   }
+\cs_new_nopar:Npn \char_make_parameter:N        #1 { \char_set_catcode:nn {`#1} {\c_six}    }
+\cs_new_nopar:Npn \char_make_math_superscript:N #1 { \char_set_catcode:nn {`#1} {\c_seven}  }
+\cs_new_nopar:Npn \char_make_math_subscript:N   #1 { \char_set_catcode:nn {`#1} {\c_eight}  }
+\cs_new_nopar:Npn \char_make_ignore:N           #1 { \char_set_catcode:nn {`#1} {\c_nine}   }
+\cs_new_nopar:Npn \char_make_space:N            #1 { \char_set_catcode:nn {`#1} {\c_ten}    }
+\cs_new_nopar:Npn \char_make_letter:N           #1 { \char_set_catcode:nn {`#1} {\c_eleven}   }
+\cs_new_nopar:Npn \char_make_other:N            #1 { \char_set_catcode:nn {`#1} {\c_twelve}   }
+\cs_new_nopar:Npn \char_make_active:N           #1 { \char_set_catcode:nn {`#1} {\c_thirteen} }
+\cs_new_nopar:Npn \char_make_comment:N          #1 { \char_set_catcode:nn {`#1} {\c_fourteen} }
+\cs_new_nopar:Npn \char_make_invalid:N          #1 { \char_set_catcode:nn {`#1} {\c_fifteen}  }
+\cs_new_nopar:Npn \char_make_escape:n           #1 { \char_set_catcode:nn {#1} {\c_zero}   }
+\cs_new_nopar:Npn \char_make_begin_group:n      #1 { \char_set_catcode:nn {#1} {\c_one}    }
+\cs_new_nopar:Npn \char_make_end_group:n        #1 { \char_set_catcode:nn {#1} {\c_two}    }
+\cs_new_nopar:Npn \char_make_math_shift:n       #1 { \char_set_catcode:nn {#1} {\c_three}  }
+\cs_new_nopar:Npn \char_make_alignment:n        #1 { \char_set_catcode:nn {#1} {\c_four}   }
+\cs_new_nopar:Npn \char_make_end_line:n         #1 { \char_set_catcode:nn {#1} {\c_five}   }
+\cs_new_nopar:Npn \char_make_parameter:n        #1 { \char_set_catcode:nn {#1} {\c_six}    }
+\cs_new_nopar:Npn \char_make_math_superscript:n #1 { \char_set_catcode:nn {#1} {\c_seven}  }
+\cs_new_nopar:Npn \char_make_math_subscript:n   #1 { \char_set_catcode:nn {#1} {\c_eight}  }
+\cs_new_nopar:Npn \char_make_ignore:n           #1 { \char_set_catcode:nn {#1} {\c_nine}   }
+\cs_new_nopar:Npn \char_make_space:n            #1 { \char_set_catcode:nn {#1} {\c_ten}    }
+\cs_new_nopar:Npn \char_make_letter:n           #1 { \char_set_catcode:nn {#1} {\c_eleven}   }
+\cs_new_nopar:Npn \char_make_other:n            #1 { \char_set_catcode:nn {#1} {\c_twelve}   }
+\cs_new_nopar:Npn \char_make_active:n           #1 { \char_set_catcode:nn {#1} {\c_thirteen} }
+\cs_new_nopar:Npn \char_make_comment:n          #1 { \char_set_catcode:nn {#1} {\c_fourteen} }
+\cs_new_nopar:Npn \char_make_invalid:n          #1 { \char_set_catcode:nn {#1} {\c_fifteen}  }
+\cs_new_eq:NN \char_set_mathcode:w \tex_mathcode:D
+\cs_new_nopar:Npn \char_set_mathcode:nn #1#2 {
+  \char_set_mathcode:w #1 = \intexpr_eval:w #2\intexpr_eval_end:
+}
+\cs_new_protected_nopar:Npn \char_gset_mathcode:w { \pref_global:D \tex_mathcode:D }
+\cs_new_nopar:Npn \char_gset_mathcode:nn #1#2 {
+  \char_gset_mathcode:w #1 = \intexpr_eval:w #2\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_value_mathcode:w { \int_use:N \tex_mathcode:D }
+\cs_new_nopar:Npn \char_value_mathcode:n #1 {
+  \char_value_mathcode:w \intexpr_eval:w #1\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_show_value_mathcode:w { \tex_showthe:D \tex_mathcode:D }
+\cs_new_nopar:Npn \char_show_value_mathcode:n #1 {
+  \char_show_value_mathcode:w \intexpr_eval:w #1\intexpr_eval_end:
+}
+\cs_new_eq:NN \char_set_lccode:w \tex_lccode:D
+\cs_new_nopar:Npn \char_set_lccode:nn #1#2{
+  \char_set_lccode:w #1 = \intexpr_eval:w #2\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_value_lccode:w {\int_use:N\tex_lccode:D}
+\cs_new_nopar:Npn \char_value_lccode:n #1{\char_value_lccode:w
+  \intexpr_eval:w #1\intexpr_eval_end:}
+\cs_new_nopar:Npn \char_show_value_lccode:w {\tex_showthe:D\tex_lccode:D}
+\cs_new_nopar:Npn \char_show_value_lccode:n #1{
+  \char_show_value_lccode:w \intexpr_eval:w #1\intexpr_eval_end:}
+\cs_new_eq:NN \char_set_uccode:w \tex_uccode:D
+\cs_new_nopar:Npn \char_set_uccode:nn #1#2{
+  \char_set_uccode:w #1 = \intexpr_eval:w #2\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_value_uccode:w {\int_use:N\tex_uccode:D}
+\cs_new_nopar:Npn \char_value_uccode:n #1{\char_value_uccode:w
+  \intexpr_eval:w #1\intexpr_eval_end:}
+\cs_new_nopar:Npn \char_show_value_uccode:w {\tex_showthe:D\tex_uccode:D}
+\cs_new_nopar:Npn \char_show_value_uccode:n #1{
+  \char_show_value_uccode:w \intexpr_eval:w #1\intexpr_eval_end:}
+\cs_new_eq:NN \char_set_sfcode:w \tex_sfcode:D
+\cs_new_nopar:Npn \char_set_sfcode:nn #1#2 {
+  \char_set_sfcode:w #1 = \intexpr_eval:w #2\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_value_sfcode:w { \int_use:N \tex_sfcode:D }
+\cs_new_nopar:Npn \char_value_sfcode:n #1 {
+  \char_value_sfcode:w \intexpr_eval:w #1\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \char_show_value_sfcode:w { \tex_showthe:D \tex_sfcode:D }
+\cs_new_nopar:Npn \char_show_value_sfcode:n #1 {
+  \char_show_value_sfcode:w \intexpr_eval:w #1\intexpr_eval_end:
+}
+\cs_new_nopar:Npn \token_new:Nn #1#2 {\cs_gnew_eq:NN #1#2}
+\cs_new_eq:NN \c_group_begin_token {
+\cs_new_eq:NN \c_group_end_token }
 \group_begin:
 \char_set_catcode:nn{`\*}{3}
 \token_new:Nn \c_math_shift_token {*}
@@ -119,260 +163,174 @@
 \token_new:Nn \c_letter_token {a}
 \token_new:Nn \c_other_char_token {1}
 \char_set_catcode:nn{`\*}{13}
-\token_new:Nn \c_active_char_token {*}
+\cs_gset_nopar:Npn \c_active_char_token {\exp_not:N*}
 \group_end:
-\def_new:Npn \token_if_group_begin_p:N #1{
+\prg_new_conditional:Nnn \token_if_group_begin:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_group_begin_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_group_begin:N} #1{
-  \if:w\token_if_group_begin_p:N #1}
-\def_new:Npn \token_if_group_end_p:N #1{
+\prg_new_conditional:Nnn \token_if_group_end:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_group_end_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_group_end:N} #1{
-  \if:w\token_if_group_end_p:N #1}
-\def_new:Npn \token_if_math_shift_p:N #1{
+\prg_new_conditional:Nnn \token_if_math_shift:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_math_shift_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_math_shift:N} #1{
-  \if:w\token_if_math_shift_p:N#1}
-\def_new:Npn \token_if_alignment_tab_p:N #1{
+\prg_new_conditional:Nnn \token_if_alignment_tab:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_alignment_tab_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_alignment_tab:N} #1{
-  \if:w\token_if_alignment_tab_p:N#1}
-\def_new:Npn \token_if_parameter_p:N #1{
-  \exp_after:NN\if_catcode:w \cs:w c_parameter_token\cs_end:\exp_not:N #1
-    \c_true
-  \else:
-    \c_false
-  \fi:
+\prg_new_conditional:Nnn \token_if_parameter:N {p,TF,T,F} {
+  \exp_after:wN\if_catcode:w \cs:w c_parameter_token\cs_end:\exp_not:N #1
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_parameter:N} #1{
-  \if:w\token_if_parameter_p:N#1}
-\def_new:Npn \token_if_math_superscript_p:N #1{
+\prg_new_conditional:Nnn \token_if_math_superscript:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_math_superscript_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_math_superscript:N} #1{
-  \if:w\token_if_math_superscript_p:N #1}
-\def_new:Npn \token_if_math_subscript_p:N #1{
+\prg_new_conditional:Nnn \token_if_math_subscript:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_math_subscript_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_math_subscript:N} #1{
-  \if:w\token_if_math_subscript_p:N #1}
-\def_new:Npn \token_if_space_p:N #1{
+\prg_new_conditional:Nnn \token_if_space:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_space_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_space:N} #1{
-  \if:w\token_if_space_p:N #1}
-\def_new:Npn \token_if_letter_p:N #1{
+\prg_new_conditional:Nnn \token_if_letter:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_letter_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_letter:N} #1{
-  \if:w\token_if_letter_p:N #1}
-\def_new:Npn \token_if_other_char_p:N #1{
+\prg_new_conditional:Nnn \token_if_other_char:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_other_char_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_other_char:N} #1{
-  \if:w\token_if_other_char_p:N #1}
-\def_new:Npn \token_if_active_char_p:N #1{
+\prg_new_conditional:Nnn \token_if_active_char:N {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1\c_active_char_token
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_active_char:N} #1{
-  \if:w\token_if_active_char_p:N #1}
-\def_new:Npn \token_if_eq_meaning_p:NN #1#2 {
-  \if_meaning:NN  #1  #2
-    \c_true
-  \else:
-    \c_false
-  \fi:
+\prg_new_conditional:Nnn \token_if_eq_meaning:NN {p,TF,T,F} {
+  \if_meaning:w  #1  #2
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_eq_meaning:NN}#1#2{
-  \if_meaning:NN  #1  #2}
-\def_new:Npn \token_if_eq_catcode_p:NN #1#2 {
+\prg_new_conditional:Nnn \token_if_eq_catcode:NN {p,TF,T,F} {
   \if_catcode:w \exp_not:N #1 \exp_not:N #2
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
 }
-\def_test_function_new:npn {token_if_eq_catcode:NN}#1#2{
-  \if:w\token_if_eq_catcode_p:NN#1#2}
-\def_new:Npn \token_if_charcode_eq_p:NN #1#2 {
+\prg_new_conditional:Nnn \token_if_eq_charcode:NN {p,TF,T,F} {
   \if_charcode:w \exp_not:N #1 \exp_not:N #2
-    \c_true
-  \else:
-    \c_false
-  \fi:
-}
-\def_test_function_new:npn {token_if_eq_charcode:NN}#1#2{
-  \if:w\token_if_eq_charcode_p:NN#1#2}
-\def_new:Npn \token_if_macro_p:N #1 {
-  \exp_after:NN \token_if_macro_p_aux:w \token_to_meaning:N #1 -> \q_nil
-}
-\def_new:Npn \token_if_macro_p_aux:w #1 -> #2 \q_nil{
-  \if:w \tlist_if_empty_p:n{#2} \c_false \else: \c_true \fi:
-}
-\def_test_function_new:npn {token_if_macro:N} #1{\if:w\token_if_macro_p:N#1}
-\def_new:Npn \token_if_cs_p:N {\token_if_eq_catcode_p:NN \scan_stop:}
-\def_test_function_new:npn {token_if_cs:N} #1{
-  \if:w \token_if_eq_catcode_p:NN \scan_stop: #1}
-\def_new:Npn \token_if_expandable_p:N #1{
-  \exp_after:NN \if_token_eq:NN \exp_not:N #1 \scan_stop:
-    \c_true
-  \else:
-    \c_false
-  \fi:
+    \prg_return_true: \else: \prg_return_false: \fi:
+}
+\prg_new_conditional:Nnn \token_if_macro:N {p,TF,T,F} {
+  \exp_after:wN \token_if_macro_p_aux:w \token_to_meaning:N #1 -> \q_nil
+}
+\cs_new_nopar:Npn \token_if_macro_p_aux:w #1 -> #2 \q_nil{
+  \if_predicate:w \tl_if_empty_p:n{#2}
+    \prg_return_false: \else: \prg_return_true: \fi:
+}
+\prg_new_conditional:Nnn \token_if_cs:N {p,TF,T,F} {
+  \if_predicate:w \token_if_eq_catcode_p:NN \scan_stop: #1
+    \prg_return_true: \else: \prg_return_false: \fi:}
+\prg_new_conditional:Nnn \token_if_expandable:N {p,TF,T,F} {
+  \cs_if_exist:NTF #1 {
+    \exp_after:wN \if_meaning:w \exp_not:N #1 #1
+      \prg_return_false: \else: \prg_return_true: \fi:
+  } {
+    \prg_return_false:
+  }
 }
-\def_test_function_new:npn {token_if_expandable:N} #1{
-  \if:w\token_if_expandable_p:N#1}
 \group_begin:
+  \char_set_lccode:nn {`\T}{`\T}
+  \char_set_lccode:nn {`\F}{`\F}
   \char_set_lccode:nn {`\X}{`\n}
   \char_set_lccode:nn {`\Y}{`\t}
   \char_set_lccode:nn {`\Z}{`\d}
   \char_set_lccode:nn {`\?}{`\\}
-  \tlist_map_inline:nn{\X\Y\Z\M\T\C\H\A\R\O\U\S\K\I\P\L\G\P\E}
+  \tl_map_inline:nn{\X\Y\Z\M\C\H\A\R\O\U\S\K\I\P\L\G\P\E}
     {\char_set_catcode:nn {`#1}{12}}
-\tlist_to_lowercase:n{
+\tl_to_lowercase:n{
   \group_end:
-\def_new:Npn \token_if_chardef_p:N #1 {
-  \exp_after:NN \token_if_chardef_p_aux:w
+\prg_new_conditional:Nnn \token_if_chardef:N {p,TF,T,F} {
+  \exp_after:wN \token_if_chardef_aux:w
   \token_to_meaning:N #1?CHAR"\q_nil
 }
-\def_new:Npn \token_if_chardef_p_aux:w #1?CHAR"#2\q_nil{
-  \tlist_if_empty_p:n{#1}
+\cs_new_nopar:Npn \token_if_chardef_aux:w #1?CHAR"#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
 }
-\def_new:Npn \token_if_mathchardef_p:N #1 {
-  \exp_after:NN \token_if_mathchardef_p_aux:w
+\prg_new_conditional:Nnn \token_if_mathchardef:N {p,TF,T,F} {
+  \exp_after:wN \token_if_mathchardef_aux:w
   \token_to_meaning:N #1?MAYHCHAR"\q_nil
 }
-\def_new:Npn \token_if_mathchardef_p_aux:w #1?MAYHCHAR"#2\q_nil{
-  \tlist_if_empty_p:n{#1}
+\cs_new_nopar:Npn \token_if_mathchardef_aux:w #1?MAYHCHAR"#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
 }
-\def:Npn \token_if_int_register_p:N #1{
-  \if_meaning:NN \tex_countdef:D #1
-    \c_false
+\prg_new_conditional:Nnn \token_if_int_register:N {p,TF,T,F} {
+  \if_meaning:w \tex_countdef:D #1
+    \prg_return_false:
   \else:
-    \exp_after:NN \token_if_int_register_p_aux:w
+    \exp_after:wN \token_if_int_register_aux:w
       \token_to_meaning:N #1?COUXY\q_nil
   \fi:
 }
-\def_new:Npn \token_if_int_register_p_aux:w #1?COUXY#2\q_nil{
-  \tlist_if_empty_p:n{#1}
+\cs_new_nopar:Npn \token_if_int_register_aux:w #1?COUXY#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
 }
-\def:Npn \token_if_skip_register_p:N #1{
-  \if_meaning:NN \tex_skipdef:D #1
-  \c_false
+\prg_new_conditional:Nnn \token_if_skip_register:N {p,TF,T,F} {
+  \if_meaning:w \tex_skipdef:D #1
+    \prg_return_false:
   \else:
-  \exp_after:NN \token_if_skip_register_p_aux:w
-  \token_to_meaning:N #1?SKIP\q_nil
+    \exp_after:wN \token_if_skip_register_aux:w
+    \token_to_meaning:N #1?SKIP\q_nil
   \fi:
 }
-\def_new:Npn \token_if_skip_register_p_aux:w #1?SKIP#2\q_nil{
-  \tlist_if_empty_p:n{#1}
+\cs_new_nopar:Npn \token_if_skip_register_aux:w #1?SKIP#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
 }
-\def:Npn \token_if_dim_register_p:N #1{
-  \if_meaning:NN \tex_dimendef:D #1
-    \c_false
+\prg_new_conditional:Nnn \token_if_dim_register:N {p,TF,T,F} {
+  \if_meaning:w \tex_dimendef:D #1
+    \c_false_bool
   \else:
-    \exp_after:NN \token_if_dim_register_p_aux:w
+    \exp_after:wN \token_if_dim_register_aux:w
     \token_to_meaning:N #1?ZIMEX\q_nil
   \fi:
 }
-\def_new:Npn \token_if_dim_register_p_aux:w #1?ZIMEX#2\q_nil{
-  \tlist_if_empty_p:n{#1}
+\cs_new_nopar:Npn \token_if_dim_register_aux:w #1?ZIMEX#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
 }
-\def:Npn \token_if_toks_register_p:N #1{
-  \if_meaning:NN \tex_toksdef:D #1
-    \c_false
+\prg_new_conditional:Nnn \token_if_toks_register:N {p,TF,T,F} {
+  \if_meaning:w \tex_toksdef:D #1
+    \prg_return_false:
   \else:
-    \exp_after:NN \token_if_toks_register_p_aux:w
+    \exp_after:wN \token_if_toks_register_aux:w
     \token_to_meaning:N #1?YOKS\q_nil
   \fi:
 }
-\def_new:Npn \token_if_toks_register_p_aux:w #1?YOKS#2\q_nil{
-  \tlist_if_empty_p:n{#1}
+\cs_new_nopar:Npn \token_if_toks_register_aux:w #1?YOKS#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
 }
-\def_new:Npn \token_if_protected_macro_p:N #1 {
-  \exp_after:NN \token_if_protected_macro_p_aux:w
+\prg_new_conditional:Nnn \token_if_protected_macro:N {p,TF,T,F} {
+  \exp_after:wN \token_if_protected_macro_aux:w
   \token_to_meaning:N #1?PROYECYEZ~MACRO\q_nil
 }
-\def_new:Npn \token_if_protected_macro_p_aux:w #1?PROYECYEZ~MACRO#2\q_nil{
-  \tlist_if_empty_p:n{#1}
+\cs_new_nopar:Npn \token_if_protected_macro_aux:w #1?PROYECYEZ~MACRO#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
 }
-\def_new:Npn \token_if_long_macro_p:N #1 {
-  \exp_after:NN \token_if_long_macro_p_aux:w
+\prg_new_conditional:Nnn \token_if_long_macro:N {p,TF,T,F} {
+  \exp_after:wN \token_if_long_macro_aux:w
   \token_to_meaning:N #1?LOXG~MACRO\q_nil
 }
-\def_new:Npn \token_if_long_macro_p_aux:w #1?LOXG~MACRO#2\q_nil{
-  \tlist_if_empty_p:n{#1}
-}
-\def_new:Npn \token_if_protected_long_macro_p:N #1 {
-  \exp_after:NN \token_if_protected_long_macro_p_aux:w
-  \token_to_meaning:N #1?PROYECYEZ~?LOXG~MACRO\q_nil
-}
-\def_new:Npn \token_if_protected_long_macro_p_aux:w #1
-  ?PROYECYEZ~?LOXG~MACRO#2\q_nil{
-  \tlist_if_empty_p:n{#1}
-}
-}
-\def_test_function_new:npn {token_if_chardef:N} {\if:w \token_if_chardef_p:N}
-\def_test_function_new:npn {token_if_mathchardef:N} {
-  \if:w \token_if_mathchardef_p:N}
-\def_test_function_new:npn {token_if_long_macro:N} {
-  \if:w \token_if_long_macro_p:N}
-\def_test_function_new:npn {token_if_protected_macro:N} {
-  \if:w \token_if_protected_macro_p:N}
-\def_test_function_new:npn {token_if_protected_long_macro:N} {
-  \if:w \token_if_protected_long_macro_p:N}
-\def_test_function_new:npn {token_if_dim_register:N} {
-  \if:w \token_if_dim_register_p:N}
-\def_test_function_new:npn {token_if_skip_register:N} {
-  \if:w \token_if_skip_register_p:N}
-\def_test_function_new:npn {token_if_int_register:N} {
-  \if:w \token_if_int_register_p:N}
-\def_test_function_new:npn {token_if_toks_register:N} {
-  \if:w \token_if_toks_register_p:N}
+\cs_new_nopar:Npn \token_if_long_macro_aux:w #1?LOXG~MACRO#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
+}
+\prg_new_conditional:Nnn \token_if_protected_long_macro:N {p,TF,T,F} {
+  \exp_after:wN \token_if_protected_long_macro_aux:w
+  \token_to_meaning:N #1?PROYECYEZ?LOXG~MACRO\q_nil
+}
+\cs_new_nopar:Npn \token_if_protected_long_macro_aux:w #1
+  ?PROYECYEZ?LOXG~MACRO#2\q_nil{
+  \tl_if_empty:nTF {#1} {\prg_return_true:} {\prg_return_false:}
+}
+}
 \group_begin:
 \char_set_lccode:nn {`\?}{`\:}
 \char_set_catcode:nn{`\M}{12}
@@ -380,63 +338,63 @@
 \char_set_catcode:nn{`\C}{12}
 \char_set_catcode:nn{`\R}{12}
 \char_set_catcode:nn{`\O}{12}
-\tlist_to_lowercase:n{
+\tl_to_lowercase:n{
   \group_end:
-  \def_new:Npn \token_get_prefix_arg_replacement_aux:w #1MACRO?#2->#3\q_nil#4{
+  \cs_new_nopar:Npn \token_get_prefix_arg_replacement_aux:w #1MACRO?#2->#3\q_nil#4{
     #4{#1}{#2}{#3}
   }
-  \def_new:Npn\token_get_prefix_spec:N #1{
+  \cs_new_nopar:Npn\token_get_prefix_spec:N #1{
     \token_if_macro:NTF #1{
-      \exp_after:NN \token_get_prefix_arg_replacement_aux:w
-      \token_to_meaning:N #1\q_nil\use_arg_i:nnn
+      \exp_after:wN \token_get_prefix_arg_replacement_aux:w
+      \token_to_meaning:N #1\q_nil\use_i:nnn
     }{\scan_stop:}
   }
-  \def_new:Npn\token_get_arg_spec:N #1{
+  \cs_new_nopar:Npn\token_get_arg_spec:N #1{
     \token_if_macro:NTF #1{
-      \exp_after:NN \token_get_prefix_arg_replacement_aux:w
-      \token_to_meaning:N #1\q_nil\use_arg_ii:nnn
+      \exp_after:wN \token_get_prefix_arg_replacement_aux:w
+      \token_to_meaning:N #1\q_nil\use_ii:nnn
     }{\scan_stop:}
   }
-  \def_new:Npn\token_get_replacement_spec:N #1{
+  \cs_new_nopar:Npn\token_get_replacement_spec:N #1{
     \token_if_macro:NTF #1{
-      \exp_after:NN \token_get_prefix_arg_replacement_aux:w
-      \token_to_meaning:N #1\q_nil\use_arg_iii:nnn
+      \exp_after:wN \token_get_prefix_arg_replacement_aux:w
+      \token_to_meaning:N #1\q_nil\use_iii:nnn
     }{\scan_stop:}
   }
 }
-\def_new:Npn \token_if_primitive_p:N #1{
-  \if:w \token_if_cs_p:N #1\scan_stop:
-    \if:w \token_if_macro_p:N #1
-      \c_false
+\prg_new_conditional:Nnn \token_if_primitive:N {p,TF,T,F} {
+  \if_predicate:w \token_if_cs_p:N #1
+    \if_predicate:w \token_if_macro_p:N #1
+      \prg_return_false:
     \else:
       \token_if_primitive_p_aux:N #1
     \fi:
   \else:
-    \if:w \token_if_active_p:N #1
-      \if:w \token_if_macro_p:N #1
-        \c_false
+    \if_predicate:w \token_if_active_char_p:N #1
+      \if_predicate:w \token_if_macro_p:N #1
+        \prg_return_false:
       \else:
         \token_if_primitive_p_aux:N #1
       \fi:
     \else:
-      \c_false
+      \prg_return_false:
     \fi:
   \fi:
 }
-\def_new:Npn \token_if_primitive_p_aux:N #1{
-  \if:w \token_if_chardef_p:N #1 \c_false
+\cs_new_nopar:Npn \token_if_primitive_p_aux:N #1{
+  \if_predicate:w \token_if_chardef_p:N #1 \c_false_bool
   \else:
-    \if:w \token_if_mathchardef_p:N #1 \c_false
+    \if_predicate:w \token_if_mathchardef_p:N #1 \prg_return_false:
     \else:
-      \if:w \token_if_int_register_p:N #1 \c_false
+      \if_predicate:w \token_if_int_register_p:N #1 \prg_return_false:
       \else:
-        \if:w \token_if_skip_register_p:N #1 \c_false
+        \if_predicate:w \token_if_skip_register_p:N #1 \prg_return_false:
         \else:
-          \if:w \token_if_dim_register_p:N #1 \c_false
+          \if_predicate:w \token_if_dim_register_p:N #1 \prg_return_false:
           \else:
-            \if:w   \token_if_toks_register_p:N #1 \c_false
+            \if_predicate:w   \token_if_toks_register_p:N #1 \prg_return_false:
             \else:
-              \c_true
+              \prg_return_true:
             \fi:
           \fi:
         \fi:
@@ -444,120 +402,161 @@
     \fi:
   \fi:
 }
-\def_test_function_new:npn {token_if_primitive:N} #1{
-  \if:w\token_if_primitive_p:N#1}
 \token_new:Nn \l_peek_token {?}
 \token_new:Nn \g_peek_token {?}
 \token_new:Nn \l_peek_search_token {?}
-\def_new:Npn \peek_after:NN {\tex_futurelet:D \l_peek_token }
-\def_new:Npn \peek_gafter:NN {
+\cs_new_nopar:Npn \peek_after:NN {\tex_futurelet:D \l_peek_token }
+\cs_new_nopar:Npn \peek_gafter:NN {
   \pref_global:D \tex_futurelet:D \g_peek_token
 }
-\tlp_new:Nn \l_peek_true_tlp {}
-\tlp_new:Nn \l_peek_false_tlp {}
-\def_new:Npn \peek_tmp:w{}
-\tlp_new:Nn \l_peek_search_tlp{}
-\def_long_new:Npn \peek_token_generic:NNTF #1#2#3#4{
-  \let:NN \l_peek_search_token #2
-  \tlp_set:Nn \l_peek_search_tlp {#2}
-  \tlp_set:Nx \l_peek_true_tlp {\exp_not:n{\group_align_safe_end: #3}}
-  \tlp_set:Nx \l_peek_false_tlp {\exp_not:n{\group_align_safe_end: #4}}
+\tl_new:Nn \l_peek_true_tl {}
+\tl_new:Nn \l_peek_false_tl {}
+\cs_new_nopar:Npn \peek_tmp:w {}
+\tl_new:Nn \l_peek_search_tl {}
+\cs_new:Npn \peek_token_generic:NNTF #1#2#3#4 {
+  \cs_set_eq:NN \l_peek_search_token #2
+  \tl_set:Nn \l_peek_search_tl {#2}
+  \tl_set:Nx \l_peek_true_tl  {\exp_not:n{\group_align_safe_end: #3}}
+  \tl_set:Nx \l_peek_false_tl {\exp_not:n{\group_align_safe_end: #4}}
   \group_align_safe_begin:
     \peek_after:NN #1
 }
-\def_long_new:Npn \peek_token_remove_generic:NNTF #1#2#3#4{
-  \let:NN \l_peek_search_token #2
-  \tlp_set:Nn \l_peek_search_tlp {#2}
-  \tlp_set:Nx \l_peek_true_aux_tlp { \exp_not:n{ #3 } }
-  \tlp_set_eq:NN \l_peek_true_tlp \c_peek_true_remove_next_tlp
-  \tlp_set:Nx \l_peek_false_tlp {\exp_not:n{\group_align_safe_end: #4}}
+\cs_new:Npn \peek_token_generic:NNT #1#2#3 {
+  \peek_token_generic:NNTF #1#2 {#3} {}
+}
+\cs_new:Npn \peek_token_generic:NNF #1#2#3 {
+  \peek_token_generic:NNTF #1#2 {} {#3}
+}
+\cs_new:Npn \peek_token_remove_generic:NNTF #1#2#3#4 {
+  \cs_set_eq:NN \l_peek_search_token #2
+  \tl_set:Nn \l_peek_search_tl {#2}
+  \tl_set:Nx \l_peek_true_aux_tl { \exp_not:n{ #3 } }
+  \tl_set_eq:NN \l_peek_true_tl \c_peek_true_remove_next_tl
+  \tl_set:Nx \l_peek_false_tl {\exp_not:n{\group_align_safe_end: #4}}
   \group_align_safe_begin:
     \peek_after:NN #1
 }
-\tlp_new:Nn \l_peek_true_aux_tlp {}
-\tlp_new:Nn \c_peek_true_remove_next_tlp {\group_align_safe_end:
-  \tex_afterassignment:D \l_peek_true_aux_tlp \let:NN \peek_tmp:w
+\cs_new:Npn \peek_token_remove_generic:NNT #1#2#3 {
+  \peek_token_remove_generic:NNTF #1#2 {#3} {}
+}
+\cs_new:Npn \peek_token_remove_generic:NNF #1#2#3 {
+  \peek_token_remove_generic:NNTF #1#2 {} {#3}
 }
-\def_new:Npn \peek_execute_branches_meaning: {
-  \if_meaning:NN \l_peek_token \l_peek_search_token
-    \exp_after:NN \l_peek_true_tlp
+\tl_new:Nn \l_peek_true_aux_tl {}
+\tl_new:Nn \c_peek_true_remove_next_tl {\group_align_safe_end:
+  \tex_afterassignment:D \l_peek_true_aux_tl \cs_set_eq:NN \peek_tmp:w
+}
+\cs_new_nopar:Npn \peek_execute_branches_meaning: {
+  \if_meaning:w \l_peek_token \l_peek_search_token
+    \exp_after:wN \l_peek_true_tl
   \else:
-    \exp_after:NN \l_peek_false_tlp
+    \exp_after:wN \l_peek_false_tl
   \fi:
 }
-\def_new:Npn \peek_execute_branches_catcode: {
+\cs_new_nopar:Npn \peek_execute_branches_catcode: {
   \if_catcode:w \exp_not:N\l_peek_token \exp_not:N\l_peek_search_token
-    \exp_after:NN \l_peek_true_tlp
+    \exp_after:wN \l_peek_true_tl
   \else:
-    \exp_after:NN \l_peek_false_tlp
+    \exp_after:wN \l_peek_false_tl
   \fi:
 }
-\def_new:Npn \peek_execute_branches_charcode: {
-  \predicate:nTF {
+\cs_new_nopar:Npn \peek_execute_branches_charcode: {
+  \bool_if:nTF {
     \token_if_eq_catcode_p:NN \l_peek_token \c_group_begin_token ||
     \token_if_eq_meaning_p:NN \l_peek_token \c_space_token
   }
-  { \l_peek_false_tlp  }
-  { \exp_after:NN \peek_execute_branches_charcode_aux:NN \l_peek_search_tlp }
+  { \l_peek_false_tl  }
+  { \exp_after:wN \peek_execute_branches_charcode_aux:NN \l_peek_search_tl }
 }
-\def_long_new:Npn \peek_execute_branches_charcode_aux:NN #1#2{
+\cs_new:Npn \peek_execute_branches_charcode_aux:NN #1#2{
   \if_charcode:w \exp_not:N #1\exp_not:N#2
-    \exp_after:NN \l_peek_true_tlp
+    \exp_after:wN \l_peek_true_tl
   \else:
-    \exp_after:NN \l_peek_false_tlp
+    \exp_after:wN \l_peek_false_tl
   \fi:
   #2
 }
-\def_new:Npn \peek_meaning:NTF {
-  \peek_token_generic:NNTF \peek_execute_branches_meaning:
-}
-\def_new:Npn \peek_meaning_ignore_spaces:NTF {
-  \let:NN \peek_execute_branches: \peek_execute_branches_meaning:
-  \peek_token_generic:NNTF \peek_ignore_spaces_execute_branches:
-}
-\def_new:Npn \peek_meaning_remove:NTF {
-  \peek_token_remove_generic:NNTF \peek_execute_branches_meaning:
-}
-\def_new:Npn \peek_meaning_remove_ignore_spaces:NTF {
-  \let:NN \peek_execute_branches: \peek_execute_branches_meaning:
-  \peek_token_remove_generic:NNTF \peek_ignore_spaces_execute_branches:
-}
-\def_new:Npn \peek_catcode:NTF {
-  \peek_token_generic:NNTF \peek_execute_branches_catcode:
-}
-\def_new:Npn \peek_catcode_ignore_spaces:NTF {
-  \let:NN \peek_execute_branches: \peek_execute_branches_catcode:
-  \peek_token_generic:NNTF \peek_ignore_spaces_execute_branches:
-}
-\def_new:Npn \peek_catcode_remove:NTF {
-  \peek_token_remove_generic:NNTF \peek_execute_branches_catcode:
-}
-\def_new:Npn \peek_catcode_remove_ignore_spaces:NTF {
-  \let:NN \peek_execute_branches: \peek_execute_branches_catcode:
-  \peek_token_remove_generic:NNTF \peek_ignore_spaces_execute_branches:
-}
-\def_new:Npn \peek_charcode:NTF {
-  \peek_token_generic:NNTF \peek_execute_branches_charcode:
-}
-\def_new:Npn \peek_charcode_ignore_spaces:NTF {
-  \let:NN \peek_execute_branches: \peek_execute_branches_charcode:
-  \peek_token_generic:NNTF \peek_ignore_spaces_execute_branches:
-}
-\def_new:Npn \peek_charcode_remove:NTF {
-  \peek_token_remove_generic:NNTF \peek_execute_branches_charcode:
-}
-
-\def_new:Npn \peek_charcode_remove_ignore_spaces:NTF {
-  \let:NN \peek_execute_branches: \peek_execute_branches_charcode:
-  \peek_token_remove_generic:NNTF \peek_ignore_spaces_execute_branches:
+\cs_new_nopar:Npn \peek_def_aux:nnnn #1#2#3#4 {
+  \peek_def_aux_ii:nnnnn {#1} {#2} {#3} {#4} { TF }
+  \peek_def_aux_ii:nnnnn {#1} {#2} {#3} {#4} { T  }
+  \peek_def_aux_ii:nnnnn {#1} {#2} {#3} {#4} { F  }
+}
+\cs_new_nopar:Npn \peek_def_aux_ii:nnnnn #1#2#3#4#5 {
+  \cs_new_nopar:cpx { #1 #5 } {
+    \tl_if_empty:nF {#2} {
+      \exp_not:n { \cs_set_eq:NN \peek_execute_branches: #2 }
+    }
+    \exp_not:c { #3 #5 }
+    \exp_not:n { #4 }
+  }
 }
-\def_new:Npn \peek_ignore_spaces_aux: {
+\peek_def_aux:nnnn
+  { peek_meaning:N }
+  {}
+  { peek_token_generic:NN }
+  { \peek_execute_branches_meaning: }
+\peek_def_aux:nnnn
+  { peek_meaning_ignore_spaces:N }
+  { \peek_execute_branches_meaning: }
+  { peek_token_generic:NN }
+  { \peek_ignore_spaces_execute_branches: }
+\peek_def_aux:nnnn
+  { peek_meaning_remove:N }
+  {}
+  { peek_token_remove_generic:NN }
+  { \peek_execute_branches_meaning: }
+\peek_def_aux:nnnn
+  { peek_meaning_remove_ignore_spaces:N }
+  { \peek_execute_branches_meaning: }
+  { peek_token_remove_generic:NN }
+  { \peek_ignore_spaces_execute_branches: }
+\peek_def_aux:nnnn
+  { peek_catcode:N }
+  {}
+  { peek_token_generic:NN }
+  { \peek_execute_branches_catcode: }
+\peek_def_aux:nnnn
+  { peek_catcode_ignore_spaces:N }
+  { \peek_execute_branches_catcode: }
+  { peek_token_generic:NN }
+  { \peek_ignore_spaces_execute_branches: }
+\peek_def_aux:nnnn
+  { peek_catcode_remove:N }
+  {}
+  { peek_token_remove_generic:NN }
+  { \peek_execute_branches_catcode: }
+\peek_def_aux:nnnn
+  { peek_catcode_remove_ignore_spaces:N }
+  { \peek_execute_branches_catcode: }
+  { peek_token_remove_generic:NN }
+  { \peek_ignore_spaces_execute_branches: }
+\peek_def_aux:nnnn
+  { peek_charcode:N }
+  {}
+  { peek_token_generic:NN }
+  { \peek_execute_branches_charcode: }
+\peek_def_aux:nnnn
+  { peek_charcode_ignore_spaces:N }
+  { \peek_execute_branches_charcode: }
+  { peek_token_generic:NN }
+  { \peek_ignore_spaces_execute_branches: }
+\peek_def_aux:nnnn
+  { peek_charcode_remove:N }
+  {}
+  { peek_token_remove_generic:NN }
+  { \peek_execute_branches_charcode: }
+\peek_def_aux:nnnn
+  { peek_charcode_remove_ignore_spaces:N }
+  { \peek_execute_branches_charcode: }
+  { peek_token_remove_generic:NN }
+  { \peek_ignore_spaces_execute_branches:}
+\cs_new_nopar:Npn \peek_ignore_spaces_aux: {
   \peek_after:NN \peek_ignore_spaces_execute_branches:
 }
-\def_new:Npn \peek_ignore_spaces_execute_branches: {
+\cs_new_nopar:Npn \peek_ignore_spaces_execute_branches: {
   \token_if_eq_meaning:NNTF \l_peek_token \c_space_token
   {  \tex_afterassignment:D \peek_ignore_spaces_aux:
-     \let:NN \peek_tmp:w
+     \cs_set_eq:NN \peek_tmp:w
   }
   \peek_execute_branches:
 }