%%
%% This is file `l3keys.sty',
%% generated with the docstrip utility.
%%
%% The original source files were:
%%
%% l3keys.dtx  (with options: `package')
%% 
%% EXPERIMENTAL CODE
%% 
%% Do not distribute this file without also distributing the
%% source files specified above.
%% 
%% Do not distribute a modified version of this file.
%% 
%% File: l3keys.dtx Copyright (C) 2006-2011 The 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
%% license or (at your option) any later version.  The latest version
%% of this license is in the file
%%
%%    http://www.latex-project.org/lppl.txt
%%
%% This file is part of the "l3kernel bundle" (The Work in LPPL)
%% and all files in that bundle must be distributed together.
%%
%% The released version of this bundle is available from CTAN.
%%
%% -----------------------------------------------------------------------
%%
%% The development version of the bundle can be found at
%%
%%    http://www.latex-project.org/svnroot/experimental/trunk/
%%
%% for those people who are interested.
%%
%%%%%%%%%%%
%% NOTE: %%
%%%%%%%%%%%
%%
%%   Snapshots taken from the repository represent work in progress and may
%%   not work or may contain conflicting material!  We therefore ask
%%   people _not_ to put them into distributions, archives, etc. without
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%% -----------------------------------------------------------------------
\RequirePackage{l3names}
\GetIdInfo$Id: l3keys.dtx 3086 2011-12-22 17:55:46Z bruno $
  {L3 Experimental key-value interfaces}
\ProvidesExplPackage
  {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
\package_check_loaded_expl:
\int_new:N \g_keyval_level_int
\tl_new:N \l_keyval_key_tl
\tl_new:N \l_keyval_value_tl
\tl_new:N \l_keyval_sanitise_tl
\tl_new:N \l_keyval_parse_tl
\group_begin:
  \char_set_catcode_active:n { `\= }
  \char_set_catcode_active:n { `\, }
  \char_set_lccode:nn { `\8 } { `\= }
  \char_set_lccode:nn { `\9 } { `\, }
\tl_to_lowercase:n
  {
    \group_end:
    \cs_new_protected:Npn \keyval_parse:n #1
      {
        \group_begin:
          \tl_clear:N \l_keyval_sanitise_tl
          \tl_set:Nn \l_keyval_sanitise_tl {#1}
          \tl_replace_all:Nnn \l_keyval_sanitise_tl { = } { 8 }
          \tl_replace_all:Nnn \l_keyval_sanitise_tl { , } { 9 }
          \tl_clear:N \l_keyval_parse_tl
          \exp_after:wN \keyval_parse_elt:w \exp_after:wN
            \q_no_value \l_keyval_sanitise_tl 9 \q_nil 9
        \exp_after:wN \group_end:
        \l_keyval_parse_tl
      }
  }
\cs_new_protected:Npn \keyval_parse_elt:w #1 ,
  {
    \tl_if_blank:oTF { \use_none:n #1 }
      { \keyval_parse_elt:w \q_no_value }
      {
        \quark_if_nil:oF { \use_ii:nn #1 }
          {
            \keyval_split_key_value:w #1 = = \q_stop
            \keyval_parse_elt:w \q_no_value
          }
      }
  }
\cs_new_protected:Npn \keyval_split_key_value:w #1 = #2 \q_stop
  {
    \keyval_split_key:w #1 \q_stop
    \str_if_eq:nnTF {#2} { = }
      {
        \tl_put_right:Nx \l_keyval_parse_tl
          {
            \exp_not:c
              { keyval_key_no_value_elt_ \int_use:N \g_keyval_level_int :n }
              { \exp_not:o \l_keyval_key_tl }
          }
      }
      {
        \keyval_split_key_value_aux:wTF #2 \q_no_value \q_stop
          { \keyval_split_value:w \q_nil #2 }
          { \msg_kernel_error:nn { keyval } { misplaced-equals-sign } }
      }
  }
\cs_new:Npn \keyval_split_key_value_aux:wTF #1 = #2#3 \q_stop
  { \tl_if_head_eq_meaning:nNTF {#3} \q_no_value }
\cs_new_protected:Npn \keyval_split_key:w #1 \q_stop
  {
    \tl_set:Nx \l_keyval_key_tl
      { \exp_after:wN \tl_trim_spaces:n \exp_after:wN { \use_none:n #1 } }
  }
\cs_new_protected:Npn \keyval_split_value:w #1 = =
  {
    \tl_put_right:Nx \l_keyval_parse_tl
      {
        \exp_not:c
          { keyval_key_value_elt_ \int_use:N \g_keyval_level_int :nn }
          { \exp_not:o \l_keyval_key_tl }
      }
    \tl_set:Nx \l_keyval_value_tl
      { \exp_not:o { \use_none:nnn #1 \q_nil \q_nil } }
    \tl_if_empty:NTF \l_keyval_value_tl
      { \tl_put_right:Nn \l_keyval_parse_tl { { } } }
      {
        \quark_if_nil:NTF \l_keyval_value_tl
          {
            \tl_put_right:Nx \l_keyval_parse_tl
              { { \exp_not:o { \use_ii:nnn #1 \q_nil } } }
          }
          { \keyval_split_value_aux:w #1 \q_stop }
      }
  }
\cs_new_protected:Npn \keyval_split_value_aux:w \q_nil #1 \q_stop
  {
    \tl_set:Nx \l_keyval_value_tl { \tl_trim_spaces:n {#1} }
    \tl_put_right:Nx \l_keyval_parse_tl
      { { \exp_not:o \l_keyval_value_tl } }
  }
\cs_new_protected:Npn \keyval_parse:NNn #1#2#3
  {
    \int_gincr:N \g_keyval_level_int
    \cs_gset_eq:cN
      { keyval_key_no_value_elt_ \int_use:N \g_keyval_level_int :n } #1
    \cs_gset_eq:cN
      { keyval_key_value_elt_ \int_use:N \g_keyval_level_int :nn }   #2
    \keyval_parse:n {#3}
    \int_gdecr:N \g_keyval_level_int
  }
\msg_kernel_new:nnnn { keyval } { misplaced-equals-sign }
  { Misplaced~equals~sign~in~key-value~input~\msg_line_number: }
  {
    LaTeX~is~attempting~to~parse~some~key-value~input~but~found~
    two~equals~signs~not~separated~by~a~comma.
  }
\tl_const:Nn \c_keys_code_root_tl { key~code~>~ }
\tl_const:Nn \c_keys_vars_root_tl { key~var~>~ }
\tl_const:Nn \c_keys_props_root_tl { key~prop~>~ }
\tl_const:Nn \c_keys_value_forbidden_tl { forbidden }
\tl_const:Nn \c_keys_value_required_tl  { required }
\int_new:N \l_keys_choice_int
\tl_new:N \l_keys_choices_tl
\tl_new:N \l_keys_key_tl
\tl_new:N \l_keys_module_tl
\bool_new:N \l_keys_no_value_bool
\tl_new:N \l_keys_path_tl
\tl_new:N \l_keys_property_tl
\tl_new:N \l_keys_unknown_clist
\tl_new:N \l_keys_value_tl
\cs_new_protected:Npn \keys_define:nn
  { \keys_define_aux:onn \l_keys_module_tl }
\cs_new_protected:Npn \keys_define_aux:nnn #1#2#3
  {
    \tl_set:Nx \l_keys_module_tl { \tl_to_str:n {#2} }
    \keyval_parse:NNn \keys_define_elt:n \keys_define_elt:nn {#3}
    \tl_set:Nn \l_keys_module_tl {#1}
  }
\cs_generate_variant:Nn \keys_define_aux:nnn { o }
\cs_new_protected:Npn \keys_define_elt:n #1
  {
    \bool_set_true:N \l_keys_no_value_bool
    \keys_define_elt_aux:nn {#1} { }
  }
\cs_new_protected:Npn \keys_define_elt:nn #1#2
  {
    \bool_set_false:N \l_keys_no_value_bool
    \keys_define_elt_aux:nn {#1} {#2}
  }
\cs_new_protected:Npn \keys_define_elt_aux:nn #1#2 {
  \keys_property_find:n {#1}
  \cs_if_exist:cTF { \c_keys_props_root_tl \l_keys_property_tl }
    { \keys_define_key:n {#2} }
    {
      \msg_kernel_error:nnxx { keys } { property-unknown }
        { \l_keys_property_tl } { \l_keys_path_tl }
    }
}
\cs_new_protected:Npn \keys_property_find:n #1
  {
    \tl_set:Nx \l_keys_path_tl { \l_keys_module_tl / }
    \tl_if_in:nnTF {#1} { . }
      { \keys_property_find_aux:w #1 \q_stop }
      { \msg_kernel_error:nnx { keys } { key-no-property } {#1} }
  }
\cs_new_protected:Npn \keys_property_find_aux:w #1 . #2 \q_stop
  {
    \tl_set:Nx \l_keys_path_tl { \l_keys_path_tl \tl_to_str:n {#1} }
    \tl_if_in:nnTF {#2} { . }
      {
        \tl_set:Nx \l_keys_path_tl { \l_keys_path_tl . }
        \keys_property_find_aux:w #2 \q_stop
      }
      { \tl_set:Nn \l_keys_property_tl { . #2 } }
  }
\cs_new_protected:Npn \keys_define_key:n #1
  {
    \bool_if:NTF \l_keys_no_value_bool
      {
        \exp_after:wN \keys_define_key_aux:w
          \l_keys_property_tl \q_stop
          { \use:c { \c_keys_props_root_tl \l_keys_property_tl } }
          {
            \msg_kernel_error:nnxx { keys }
              { property-requires-value } { \l_keys_property_tl }
              { \l_keys_path_tl }
            }
      }
      { \use:c { \c_keys_props_root_tl \l_keys_property_tl } {#1} }
  }
\cs_new_protected:Npn \keys_define_key_aux:w #1 : #2 \q_stop
  { \tl_if_empty:nTF {#2} }
\cs_new:Npn \keys_bool_set:NN #1#2
  {
    \cs_if_exist:NF #1 { \bool_new:N #1 }
    \keys_choice_make:
    \keys_cmd_set:nx { \l_keys_path_tl / true }
      { \exp_not:c { bool_ #2 set_true:N } \exp_not:N #1 }
    \keys_cmd_set:nx { \l_keys_path_tl / false }
      { \exp_not:c { bool_ #2 set_false:N } \exp_not:N #1 }
    \keys_cmd_set:nn { \l_keys_path_tl / unknown }
      {
        \msg_kernel_error:nnx { keys } { boolean-values-only }
          { \l_keys_key_tl }
      }
    \keys_default_set:n { true }
  }
\cs_new:Npn \keys_bool_set_inverse:NN #1#2
  {
    \cs_if_exist:NF #1 { \bool_new:N #1 }
    \keys_choice_make:
    \keys_cmd_set:nx { \l_keys_path_tl / true }
      { \exp_not:c { bool_ #2 set_false:N } \exp_not:N #1 }
    \keys_cmd_set:nx { \l_keys_path_tl / false }
      { \exp_not:c { bool_ #2 set_true:N } \exp_not:N #1 }
    \keys_cmd_set:nn { \l_keys_path_tl / unknown }
      {
        \msg_kernel_error:nnx { keys } { boolean-values-only }
          { \l_keys_key_tl }
      }
    \keys_default_set:n { true }
  }
\cs_new_protected_nopar:Npn \keys_choice_make:
  {
    \keys_cmd_set:nn { \l_keys_path_tl }
      { \keys_choice_find:n {##1} }
    \keys_cmd_set:nn { \l_keys_path_tl / unknown }
      {
        \msg_kernel_error:nnxx { keys } { choice-unknown }
          { \l_keys_path_tl } {##1}
      }
  }
\cs_new_protected:Npn \keys_choices_make:nn #1#2
  {
    \keys_choice_make:
    \int_zero:N \l_keys_choice_int
    \clist_map_inline:nn {#1}
      {
        \keys_cmd_set:nx { \l_keys_path_tl / ##1 }
          {
            \tl_set:Nn \exp_not:N \l_keys_choice_tl {##1}
            \int_set:Nn \exp_not:N \l_keys_choice_int
              { \int_use:N \l_keys_choice_int }
            \exp_not:n {#2}
          }
        \int_incr:N \l_keys_choice_int
      }
  }
\cs_new_protected:Npn \keys_choices_generate:n #1
  {
    \cs_if_exist:cTF
      { \c_keys_vars_root_tl \l_keys_path_tl .choice~code }
      {
        \keys_choice_make:
        \int_zero:N \l_keys_choice_int
        \clist_map_function:nN {#1} \keys_choices_generate_aux:n
      }
      {
        \msg_kernel_error:nnx { keys }
          { generate-choices-before-code } { \l_keys_path_tl }
      }
  }
\cs_new_protected:Npn \keys_choices_generate_aux:n #1
  {
    \keys_cmd_set:nx { \l_keys_path_tl / #1 }
      {
        \tl_set:Nn \exp_not:N \l_keys_choice_tl {#1}
        \int_set:Nn \exp_not:N \l_keys_choice_int
          { \int_use:N \l_keys_choice_int }
        \exp_not:v
          { \c_keys_vars_root_tl \l_keys_path_tl .choice~code }
      }
    \int_incr:N \l_keys_choice_int
  }
\cs_new_protected:Npn \keys_choice_code_store:x #1
  {
    \cs_if_exist:cF
      { \c_keys_vars_root_tl \l_keys_path_tl .choice~code }
      {
        \tl_new:c
          { \c_keys_vars_root_tl \l_keys_path_tl .choice~code }
      }
    \tl_set:cx { \c_keys_vars_root_tl \l_keys_path_tl .choice~code }
      {#1}
  }
\cs_new_protected:Npn \keys_cmd_set:nn #1#2
  {
    \keys_cmd_set_aux:n {#1}
    \cs_set:cpn { \c_keys_code_root_tl #1 } ##1 {#2}
  }
\cs_new_protected:Npn \keys_cmd_set:nx #1#2
  {
    \keys_cmd_set_aux:n {#1}
    \cs_set:cpx { \c_keys_code_root_tl #1 } ##1 {#2}
  }
\cs_new_protected:Npn \keys_cmd_set_aux:n #1
  {
    \tl_clear_new:c { \c_keys_vars_root_tl #1 .default }
    \tl_set:cn { \c_keys_vars_root_tl #1 .default } { \q_no_value }
    \tl_clear_new:c { \c_keys_vars_root_tl #1 .req }
  }
\cs_new_protected:Npn \keys_default_set:n #1
  { \tl_set:cn { \c_keys_vars_root_tl \l_keys_path_tl .default } {#1} }
\cs_generate_variant:Nn \keys_default_set:n { V }
\cs_new_protected:Npn \keys_meta_make:n #1
  {
    \exp_args:NNo \keys_cmd_set:nn \l_keys_path_tl
      { \exp_after:wN \keys_set:nn \exp_after:wN { \l_keys_module_tl } {#1} }
  }
\cs_new_protected:Npn \keys_meta_make:x #1
  {
    \keys_cmd_set:nx { \l_keys_path_tl }
      { \exp_not:N \keys_set:nn { \l_keys_module_tl } {#1} }
  }
\cs_new:Npn \keys_multichoice_find:n #1
  { \clist_map_function:nN {#1} \keys_choice_find:n }
\cs_new_protected_nopar:Npn \keys_multichoice_make:
  {
    \keys_cmd_set:nn { \l_keys_path_tl }
      { \keys_multichoice_find:n {##1} }
    \keys_cmd_set:nn { \l_keys_path_tl / unknown }
      {
        \msg_kernel_error:nnxx { keys } { choice-unknown }
          { \l_keys_path_tl } {##1}
      }
  }
\cs_new_protected:Npn \keys_multichoices_make:nn #1#2
  {
    \keys_multichoice_make:
    \int_zero:N \l_keys_choice_int
    \clist_map_inline:nn {#1}
      {
        \keys_cmd_set:nx { \l_keys_path_tl / ##1 }
          {
            \tl_set:Nn \exp_not:N \l_keys_choice_tl {##1}
            \int_set:Nn \exp_not:N \l_keys_choice_int
              { \int_use:N \l_keys_choice_int }
            \exp_not:n {#2}
          }
        \int_incr:N \l_keys_choice_int
      }
  }
\cs_new_protected:Npn \keys_value_requirement:n #1
  {
    \tl_set_eq:cc
      { \c_keys_vars_root_tl \l_keys_path_tl .req }
      { c_keys_value_ #1 _tl }
  }
\cs_new_protected:Npn \keys_variable_set:NnNN #1#2#3#4
  {
    \cs_if_exist:NF #1 { \use:c { #2 _new:N } #1 }
    \keys_cmd_set:nx { \l_keys_path_tl }
      { \exp_not:c { #2 _ #3 set:N #4 } \exp_not:N #1 {##1} }
  }
\cs_new_protected:Npn \keys_variable_set:NnN #1#2#3
  { \keys_variable_set:NnNN #1 {#2} { } #3 }
\cs_generate_variant:Nn \keys_variable_set:NnNN { c }
\cs_generate_variant:Nn \keys_variable_set:NnN  { c }
\cs_new_protected:cpn { \c_keys_props_root_tl .bool_set:N } #1
  { \keys_bool_set:NN #1 { } }
\cs_new_protected:cpn { \c_keys_props_root_tl .bool_gset:N } #1
  { \keys_bool_set:NN #1 g }
\cs_new_protected:cpn { \c_keys_props_root_tl .bool_set_inverse:N } #1
  { \keys_bool_set_inverse:NN #1 { } }
\cs_new_protected:cpn { \c_keys_props_root_tl .bool_gset_inverse:N } #1
  { \keys_bool_set_inverse:NN #1 g }
\cs_new_protected_nopar:cpn { \c_keys_props_root_tl .choice: }
  { \keys_choice_make: }
\cs_new_protected:cpn { \c_keys_props_root_tl .choices:nn } #1
  { \keys_choices_make:nn #1 }
\cs_new_protected:cpn { \c_keys_props_root_tl .code:n } #1
  { \keys_cmd_set:nn { \l_keys_path_tl } {#1} }
\cs_new_protected:cpn { \c_keys_props_root_tl .code:x } #1
  { \keys_cmd_set:nx { \l_keys_path_tl } {#1} }
\cs_new_protected:cpn { \c_keys_props_root_tl .choice_code:n } #1
  { \keys_choice_code_store:x { \exp_not:n {#1} } }
\cs_new_protected:cpn { \c_keys_props_root_tl .choice_code:x } #1
  { \keys_choice_code_store:x {#1} }
\cs_new_protected:cpn { \c_keys_props_root_tl .clist_set:N } #1
  { \keys_variable_set:NnN #1 { clist } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .clist_set:c } #1
  { \keys_variable_set:cnN {#1} { clist } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .clist_gset:N } #1
  { \keys_variable_set:NnNN #1 { clist } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .clist_gset:c } #1
  { \keys_variable_set:cnNN {#1} { clist } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .default:n } #1
  { \keys_default_set:n {#1} }
\cs_new_protected:cpn { \c_keys_props_root_tl .default:V } #1
  { \keys_default_set:V #1 }
\cs_new_protected:cpn { \c_keys_props_root_tl .dim_set:N } #1
  { \keys_variable_set:NnN #1 { dim } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .dim_set:c } #1
  { \keys_variable_set:cnN {#1} { dim } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .dim_gset:N } #1
  { \keys_variable_set:NnNN #1 { dim } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .dim_gset:c } #1
  { \keys_variable_set:cnNN {#1} { dim } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .fp_set:N } #1
  { \keys_variable_set:NnN #1 { fp } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .fp_set:c } #1
  { \keys_variable_set:cnN {#1} { fp } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .fp_gset:N } #1
  { \keys_variable_set:NnNN #1 { fp } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .fp_gset:c } #1
  { \keys_variable_set:cnNN {#1} { fp } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .generate_choices:n } #1
  { \keys_choices_generate:n {#1} }
\cs_new_protected:cpn { \c_keys_props_root_tl .int_set:N } #1
  { \keys_variable_set:NnN #1 { int } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .int_set:c } #1
  { \keys_variable_set:cnN {#1} { int } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .int_gset:N } #1
  { \keys_variable_set:NnNN #1 { int } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .int_gset:c } #1
  { \keys_variable_set:cnNN {#1} { int } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .meta:n } #1
  { \keys_meta_make:n {#1} }
\cs_new_protected:cpn { \c_keys_props_root_tl .meta:x } #1
  { \keys_meta_make:x {#1} }
\cs_new_protected_nopar:cpn { \c_keys_props_root_tl .multichoice: }
  { \keys_multichoice_make: }
\cs_new_protected:cpn { \c_keys_props_root_tl .multichoices:nn } #1
  { \keys_multichoices_make:nn #1 }
\cs_new_protected:cpn { \c_keys_props_root_tl .skip_set:N } #1
  { \keys_variable_set:NnN #1 { skip } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .skip_set:c } #1
  { \keys_variable_set:cnN {#1} { skip } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .skip_gset:N } #1
  { \keys_variable_set:NnNN #1 { skip } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .skip_gset:c } #1
  { \keys_variable_set:cnNN {#1} { skip } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_set:N } #1
   { \keys_variable_set:NnN #1 { tl } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_set:c } #1
  { \keys_variable_set:cnN {#1} { tl } n }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_set_x:N } #1
  { \keys_variable_set:NnN #1 { tl } x }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_set_x:c } #1
  { \keys_variable_set:cnN {#1} { tl } x }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_gset:N } #1
  { \keys_variable_set:NnNN #1 { tl } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_gset:c } #1
  { \keys_variable_set:cnNN {#1} { tl } g n }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_gset_x:N } #1
  { \keys_variable_set:NnNN #1 { tl } g x }
\cs_new_protected:cpn { \c_keys_props_root_tl .tl_gset_x:c } #1
  { \keys_variable_set:cnNN {#1} { tl } g x }
\cs_new_protected_nopar:cpn { \c_keys_props_root_tl .value_forbidden: }
  { \keys_value_requirement:n { forbidden } }
\cs_new_protected_nopar:cpn { \c_keys_props_root_tl .value_required: }
  { \keys_value_requirement:n { required } }
\cs_new_protected:Npn \keys_set:nn
  { \keys_set_aux:onn { \l_keys_module_tl } }
\cs_new_protected:Npn \keys_set_aux:nnn #1#2#3
  {
    \tl_set:Nx \l_keys_module_tl { \tl_to_str:n {#2} }
    \keyval_parse:NNn \keys_set_elt:n \keys_set_elt:nn {#3}
    \tl_set:Nn \l_keys_module_tl {#1}
  }
\cs_generate_variant:Nn \keys_set:nn { nV , nv , no }
\cs_generate_variant:Nn \keys_set_aux:nnn { o }
\cs_new_protected:Npn \keys_set_known:nnN
  { \keys_set_known_aux:onnN { \l_keys_module_tl } }
\cs_new_protected:Npn \keys_set_known_aux:nnnN #1#2#3#4
  {
    \tl_set:Nx \l_keys_module_tl { \tl_to_str:n {#2} }
    \clist_clear:N \l_keys_unknown_clist
    \cs_set_eq:NN \keys_execute_unknown: \keys_execute_unknown_alt:
    \keyval_parse:NNn \keys_set_elt:n \keys_set_elt:nn {#3}
    \cs_set_eq:NN \keys_execute_unknown: \keys_execute_unknown_std:
    \tl_set:Nn \l_keys_module_tl {#1}
    \clist_set_eq:NN #4 \l_keys_unknown_clist
  }
\cs_generate_variant:Nn \keys_set_known:nnN { nV , nv , no }
\cs_generate_variant:Nn \keys_set_known_aux:nnnN { o }
\cs_new_protected:Npn \keys_set_elt:n #1
  {
    \bool_set_true:N \l_keys_no_value_bool
    \keys_set_elt_aux:nn {#1} { }
  }
\cs_new_protected:Npn \keys_set_elt:nn #1#2
  {
    \bool_set_false:N \l_keys_no_value_bool
    \keys_set_elt_aux:nn {#1} {#2}
  }
\cs_new_protected:Npn \keys_set_elt_aux:nn #1#2
  {
    \tl_set:Nx \l_keys_key_tl { \tl_to_str:n {#1} }
    \tl_set:Nx \l_keys_path_tl { \l_keys_module_tl / \l_keys_key_tl }
    \keys_value_or_default:n {#2}
    \bool_if:nTF
      {
        \keys_if_value_p:n { required } &&
        \l_keys_no_value_bool
      }
      {
        \msg_kernel_error:nnx { keys } { value-required }
          { \l_keys_path_tl }
      }
      {
        \bool_if:nTF
          {
              \keys_if_value_p:n { forbidden } &&
            ! \l_keys_no_value_bool
          }
          {
            \msg_kernel_error:nnxx { keys } { value-forbidden }
              { \l_keys_path_tl } { \l_keys_value_tl }
          }
          { \keys_execute: }
      }
  }
\cs_new_protected:Npn \keys_value_or_default:n #1
  {
    \tl_set:Nn \l_keys_value_tl {#1}
    \bool_if:NT \l_keys_no_value_bool
      {
        \quark_if_no_value:cF { \c_keys_vars_root_tl \l_keys_path_tl .default }
          {
            \cs_if_exist:cT { \c_keys_vars_root_tl \l_keys_path_tl .default }
              {
                \tl_set_eq:Nc \l_keys_value_tl
                  { \c_keys_vars_root_tl \l_keys_path_tl .default }
              }
          }
      }
  }
\prg_new_conditional:Npnn \keys_if_value:n #1 { p }
  {
    \tl_if_eq:ccTF { c_keys_value_ #1 _tl }
      { \c_keys_vars_root_tl \l_keys_path_tl .req }
      { \prg_return_true: }
      { \prg_return_false: }
  }
\cs_new_nopar:Npn \keys_execute:
  { \keys_execute:nn { \l_keys_path_tl } { \keys_execute_unknown: } }
\cs_new_nopar:Npn \keys_execute_unknown:
  {
    \keys_execute:nn { \l_keys_module_tl / unknown }
      {
        \msg_kernel_error:nnxx { keys } { key-unknown }
          { \l_keys_path_tl } { \l_keys_module_tl }
      }
  }
\cs_new_eq:NN \keys_execute_unknown_std: \keys_execute_unknown:
\cs_new_nopar:Npn \keys_execute_unknown_alt:
  {
    \clist_put_right:Nx \l_keys_unknown_clist
      {
        \exp_not:o \l_keys_key_tl
        \bool_if:NF \l_keys_no_value_bool
          { = { \exp_not:o \l_keys_value_tl } }
      }
  }
\cs_new:Npn \keys_execute:nn #1#2
  {
    \cs_if_exist:cTF { \c_keys_code_root_tl #1 }
      {
        \exp_args:Nno \use:c { \c_keys_code_root_tl #1 }
          \l_keys_value_tl
      }
      {#2}
  }
\cs_new:Npn \keys_choice_find:n #1
  {
    \keys_execute:nn { \l_keys_path_tl / \tl_to_str:n {#1} }
      { \keys_execute:nn { \l_keys_path_tl / unknown } { } }
  }
\prg_new_conditional:Npnn \keys_if_exist:nn #1#2 { p , T , F , TF }
  {
    \cs_if_exist:cTF { \c_keys_code_root_tl #1 / #2 }
      { \prg_return_true: }
      { \prg_return_false: }
  }
\prg_new_conditional:Npnn \keys_if_choice_exist:nnn #1#2#3 { p , T , F , TF }
  {
    \cs_if_exist:cTF { \c_keys_code_root_tl #1 / #2 / #3 }
      { \prg_return_true: }
      { \prg_return_false: }
  }
\cs_new:Npn \keys_show:nn #1#2
  { \cs_show:c { \c_keys_code_root_tl #1 / \tl_to_str:n {#2} } }
\msg_kernel_new:nnnn { keys } { boolean-values-only }
  { Key~'#1'~accepts~boolean~values~only. }
  { The~key~'#1'~only~accepts~the~values~'true'~and~'false'. }
\msg_kernel_new:nnnn { keys } { choice-unknown }
  { Choice~'#2'~unknown~for~key~'#1'. }
  {
    The~key~'#1'~takes~a~limited~number~of~values.\\
    The~input~given,~'#2',~is~not~on~the~list~accepted.
  }
\msg_kernel_new:nnnn { keys } { generate-choices-before-code }
  { No~code~available~to~generate~choices~for~key~'#1'. }
  {
    \c_msg_coding_error_text_tl
    Before~using~.generate_choices:n~the~code~should~be~defined~
    with~'.choice_code:n'~or~'.choice_code:x'.
  }
\msg_kernel_new:nnnn { keys } { key-no-property }
  { No~property~given~in~definition~of~key~'#1'. }
  {
    \c_msg_coding_error_text_tl
    Inside~\keys_define:nn each~key~name
    needs~a~property:  \\
    ~ ~ #1 .<property> \\
    LaTeX~did~not~find~a~'.'~to~indicate~the~start~of~a~property.
  }
\msg_kernel_new:nnnn { keys } { key-unknown }
  { The~key~'#1'~is~unknown~and~is~being~ignored. }
  {
    The~module~'#2'~does~not~have~a~key~called~#1'.\\
    Check~that~you~have~spelled~the~key~name~correctly.
  }
\msg_kernel_new:nnnn { keys } { option-unknown }
  { Unknown~option~'#1'~for~package~#2. }
  {
    LaTeX~has~been~asked~to~set~an~option~called~'#1'~
    but~the~#2~package~has~not~created~an~option~with~this~name.
  }
\msg_kernel_new:nnnn { keys } { property-requires-value }
  { The~property~'#1'~requires~a~value. }
  {
    \c_msg_coding_error_text_tl
    LaTeX~was~asked~to~set~property~'#2'~for~key~'#1'.\\
    No~value~was~given~for~the~property,~and~one~is~required.
  }
\msg_kernel_new:nnnn { keys } { property-unknown }
  { The~key~property~'#1'~is~unknown. }
  {
    \c_msg_coding_error_text_tl
    LaTeX~has~been~asked~to~set~the~property~'#1'~for~key~'#2':~
    this~property~is~not~defined.
  }
\msg_kernel_new:nnnn { keys } { value-forbidden }
  { The~key~'#1'~does~not~taken~a~value. }
  {
    The~key~'#1'~should~be~given~without~a~value.\\
    LaTeX~will~ignore~the~given~value~'#2'.
  }
\msg_kernel_new:nnnn { keys } { value-required }
  { The~key~'#1'~requires~a~value. }
  {
    The~key~'#1'~must~have~a~value.\\
    No~value~was~present:~the~key~will~be~ignored.
  }
%% 
%%
%% End of file `l3keys.sty'.