tasks (20jul14)

git-svn-id: svn://tug.org/texlive/trunk@34674 c570f23f-e606-0410-a88d-b1316a301751

2 files changed, 805 insertions, 0 deletions

diff --git a/Master/texmf-dist/tex/latex/tasks/tasks.cfg b/Master/texmf-dist/tex/latex/tasks/tasks.cfg
new file mode 100644
index 00000000000..12b3c50517c
--- /dev/null
+++ b/Master/texmf-dist/tex/latex/tasks/tasks.cfg
@@ -0,0 +1,52 @@
+% --------------------------------------------------------------------------
+% the TASKS package
+% 
+%   Horizontal columned lists.
+% 
+% --------------------------------------------------------------------------
+% Clemens Niederberger
+% Web:    https://github.com/cgnieder/tasks/
+% E-Mail: contact@mychemistry.eu
+% --------------------------------------------------------------------------
+% Copyright 2013-2014 Clemens Niederberger
+% 
+% 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.
+% 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'.
+% 
+% The Current Maintainer of this work is Clemens Niederberger.
+% --------------------------------------------------------------------------
+% If you have any ideas, questions, suggestions or bugs to report, please
+% feel free to contact me.
+% --------------------------------------------------------------------------
+% further instances for the `tasks' environment
+\ProvidesFile{tasks.cfg}
+  [\@tasks@date\space v\@tasks@version\space tasks instances]
+
+\cs_new:Npn \tasks_config_file_loaded: {}
+
+% ITEMIZE:
+\DeclareInstance {tasks} {itemize} {default}
+  {
+    enumerate    = false ,
+    label-width  = 1.125em
+  }
+
+% ENUMERATE:
+\DeclareInstance {tasks} {enumerate} {default}
+  { counter-format = tsk. }
+
+% MULTIPLECHOICE
+\DeclareInstance {tasks} {multiplechoice} {default}
+  {
+    enumerate    = false ,
+    label        = \choicebox
+  }
+
+\tex_endinput:D
diff --git a/Master/texmf-dist/tex/latex/tasks/tasks.sty b/Master/texmf-dist/tex/latex/tasks/tasks.sty
new file mode 100644
index 00000000000..7de903b8e35
--- /dev/null
+++ b/Master/texmf-dist/tex/latex/tasks/tasks.sty
@@ -0,0 +1,753 @@
+% --------------------------------------------------------------------------
+% the TASKS package
+% 
+%   Horizontal columned lists.
+% 
+% --------------------------------------------------------------------------
+% Clemens Niederberger
+% Web:    https://github.com/cgnieder/tasks/
+% E-Mail: contact@mychemistry.eu
+% --------------------------------------------------------------------------
+% Copyright 2013-2014 Clemens Niederberger
+% 
+% 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.
+% 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'.
+% 
+% The Current Maintainer of this work is Clemens Niederberger.
+% --------------------------------------------------------------------------
+% If you have any ideas, questions, suggestions or bugs to report, please
+% feel free to contact me.
+% --------------------------------------------------------------------------
+\def\@tasks@date{2014/07/20}
+\def\@tasks@version{0.10}
+
+\RequirePackage { expl3 , xparse , l3keys2e }
+\ProvidesExplPackage
+  {tasks}
+  {\@tasks@date}
+  {\@tasks@version}
+  {Horizontal columned lists.}
+
+% --------------------------------------------------------------------------
+% check expl3 version:
+\@ifpackagelater { expl3 } { 2014/01/01 }
+  { }
+  {
+    \PackageError { tasks } { Support~package~expl3~too~old }
+      {
+        You~need~to~update~your~installation~of~the~bundles~'l3kernel'~and~
+        'l3packages'.\MessageBreak
+        Loading~tasks~will~abort!
+      }
+    \tex_endinput:D
+  }
+
+% --------------------------------------------------------------------------
+% requirements:
+\RequirePackage { epic , cntformats , xtemplate , environ }
+
+\msg_new:nnn {tasks} {deprecated-option}
+  {
+    The~ option~ `#1'~ has~ been~ removed~ from~ the~ `tasks'~ package.~
+    Please~ see~ the~ documentation~ for~details.
+  }
+
+
+% --------------------------------------------------------------------------
+% variants of kernel functions:
+\cs_generate_variant:Nn \tl_if_eq:nnTF { V }
+\cs_generate_variant:Nn \tl_if_eq:nnT  { V }
+
+% --------------------------------------------------------------------------
+% variables:
+\seq_new:N    \l__tasks_seq
+
+\int_new:N    \l__tasks_depth_int
+\int_new:N    \g__tasks_int
+\int_new:N    \g__tasks_total_items_int
+\int_new:N    \l__tasks_columns_int
+\int_new:N    \l__tasks_rows_int
+\int_new:N    \g__tasks_current_col_num_int
+\int_new:N    \g__tasks_current_row_num_int
+\int_new:N    \l__tasks_item_columns_int
+
+\bool_new:N   \l__tasks_enumerate_bool
+\bool_new:N   \l__tasks_resume_bool
+\bool_new:N   \l__tasks_load_tasks_bool
+\bool_new:N   \l__tasks_label_width_bool
+\bool_new:N   \l__tasks_item_indent_bool
+\bool_new:N   \l__tasks_label_offset_bool
+\bool_new:N   \l__tasks_custom_label_bool
+\bool_new:N   \l__tasks_custom_after_item_skip_bool
+\bool_new:N   \l__tasks_debug_bool
+\bool_new:N   \l__tasks_item_full_line_bool
+\bool_new:N   \l__tasks_item_rest_of_line_bool
+
+\tl_new:N     \l__tasks_instance_tl
+\tl_new:N     \l__tasks_label_tl
+\tl_new:N     \l__tasks_custom_label_tl
+\tl_new:N     \l__tasks_label_pattern_tl
+\tl_new:N     \l__tasks_custom_label_pattern_tl
+\tl_new:N     \l__tasks_label_format_tl
+\tl_new:N     \l__tasks_custom_label_format_tl
+\tl_new:N     \l__tasks_item_fill_left_tl
+\tl_new:N     \l__tasks_item_fill_right_tl
+\tl_new:N     \l__tasks_label_align_tl
+% \tl_new:N     \task
+\tl_new:N     \l__tasks_item_tl
+\tl_new:N     \l__tasks_tmp_label_tl
+
+\dim_new:N    \l__tasks_item_indent_dim
+\dim_new:N    \l__tasks_item_default_indent_dim
+\dim_new:N    \l__tasks_item_width_dim
+\dim_new:N    \l__tasks_label_width_dim
+\dim_new:N    \l__tasks_label_default_width_dim
+\dim_new:N    \l__tasks_label_offset_dim
+\dim_new:N    \l__tasks_label_default_offset_dim
+\dim_new:N    \l__tasks_column_sep_dim
+
+\skip_new:N   \l__tasks_after_item_skip
+\skip_new:N   \l__tasks_custom_after_item_skip
+\skip_new:N   \l__tasks_before_list_skip
+\skip_new:N   \l__tasks_after_list_skip
+
+\coffin_new:N \l__tasks_item_coffin
+\coffin_new:N \l__tasks_label_coffin
+
+\NewCounterPattern* [ tasks ] { task } { tsk }
+\ReadCounterFrom [ tasks ] { task } \g__tasks_int
+
+% temporary variables:
+\int_new:N    \l__tasks_tmpa_int
+\int_new:N    \l__tasks_tmpb_int
+\tl_new:N     \l__tasks_tmpa_tl
+\coffin_new:N \l__tasks_tmpa_coffin
+
+\cs_new:Npn \__tasks_debug:n #1
+  {
+    \bool_if:NTF \l__tasks_debug_bool
+      { \fbox {#1} }
+      { \use:n {#1} }
+  }
+
+% --------------------------------------------------------------------------
+% collect the tasks:
+\cs_new_protected:Npn \__tasks_collect_tasks:nww #1#2 \end #3
+  {
+    \tl_put_right:Nn \l__tasks_body_tl { #1 }
+    \end { #3 }
+    \tl_if_eq:nnF { #1 } { #3 }
+      { \__tasks_collect_tasks:nww { #1 } }
+  }
+
+%  #1: instance
+%  #2: number of columns
+%  #3: item separator
+%  #4: environment body
+\cs_new_protected:Npn \__tasks:nnnn #1#2#3#4
+  {
+    \bool_if:NT \l__tasks_debug_bool { \dim_set:Nn \fboxsep {0pt} }
+    \seq_set_split:Nnn \l__tasks_seq { #3 } { #4 }
+    % remove the first (empty) item:
+    \seq_pop_left:NN \l__tasks_seq \l__tasks_tmpa_tl
+    \tl_if_blank:VF \l__tasks_tmpa_tl { \@noitemerr }
+    \int_gset:Nn \g__tasks_total_items_int
+      { \seq_count:N \l__tasks_seq }
+    \UseInstance { tasks } { #1 }
+      { \g__tasks_total_items_int }
+      { #2 }
+      { \l__tasks_custom_label_pattern_tl }
+    % just to be sure:
+    \seq_clear:N \l__tasks_seq
+  }
+\cs_generate_variant:Nn \__tasks:nnnn { VnnV }
+
+\cs_new_protected:Npn \__tasks_task:nnwwwwww #1#2[#3,#4][#5,#6](#7,#8)
+  {
+    % start a new item line if \l__tasks_item_full_line_bool
+    \bool_if:NT \l__tasks_item_full_line_bool
+      {
+        % add skip if we were in the middle of a line, i.e., in horizontal
+        % mode:
+        \mode_if_horizontal:T
+          { \skip_vertical:N \l__tasks_after_item_skip }
+        \tasks_new_row:
+      }
+    \int_gincr:N \g__tasks_current_col_num_int
+    \dim_set:Nn \l__tasks_item_width_dim
+      {
+        \bool_if:NTF \l__tasks_item_full_line_bool
+          { \linewidth }
+          {
+            (
+              \linewidth
+              - \l__tasks_columns_int \l__tasks_column_sep_dim
+              + \l__tasks_column_sep_dim
+            ) / \l__tasks_columns_int
+          }
+        - \l__tasks_depth_int \l__tasks_item_indent_dim
+        \bool_if:NT \l__tasks_debug_bool { -2\fboxrule }
+      }
+    \__tasks_gset_rows_num:NN
+      \g__tasks_total_items_int
+      \l__tasks_columns_int
+    % set \g__tasks_current_col_num_int to 1 if at the start of a row,
+    % the also step \g__tasks_current_row_num_int :
+    \int_compare:nNnT { \g__tasks_current_col_num_int } > { \l__tasks_columns_int }
+      {
+        \int_gset:Nn \g__tasks_current_col_num_int { 1 }
+        \int_incr:N \g__tasks_current_row_num_int
+      }
+    \bool_if:NT \l__tasks_item_rest_of_line_bool
+      {
+        \int_compare:nNnTF { \l__tasks_item_columns_int } = { 0 }
+          {
+            \int_set:Nn \l__tasks_tmpa_int
+              { \l__tasks_columns_int - \g__tasks_current_col_num_int + 1 }
+            \int_set:Nn \l__tasks_tmpb_int { \l__tasks_tmpa_int -1 }
+          }
+          {
+            \int_set:Nn \l__tasks_tmpa_int
+              { \l__tasks_columns_int - \g__tasks_current_col_num_int + 1 }
+            \int_compare:nNnTF
+              { \l__tasks_tmpa_int } > { \l__tasks_item_columns_int }
+              { \int_set_eq:NN \l__tasks_tmpa_int \l__tasks_item_columns_int }
+              { \int_zero:N \l__tasks_item_columns_int }
+            \bool_if:nT
+              {
+                \l__tasks_item_rest_of_line_bool &&
+                !\int_compare_p:nNn { \l__tasks_item_columns_int} = { 0 }
+              }
+              {
+                \int_gadd:Nn \g__tasks_current_col_num_int
+                  { \l__tasks_item_columns_int -1 }
+                \int_gadd:Nn \g__tasks_total_items_int
+                  { \l__tasks_item_columns_int -1 }
+              }
+            \int_set:Nn \l__tasks_tmpb_int { \l__tasks_tmpa_int -1 }
+          }
+        \dim_set:Nn \l__tasks_item_width_dim
+          {
+            \l__tasks_tmpa_int \l__tasks_item_width_dim
+            + \l__tasks_tmpb_int \l__tasks_column_sep_dim
+            + \l__tasks_tmpb_int \l__tasks_item_indent_dim
+            \bool_if:NT \l__tasks_debug_bool
+              { + \int_eval:n { \l__tasks_tmpb_int * 2 } \fboxrule }
+          }
+      }
+    % set the item box:
+    \hcoffin_set:Nn \l__tasks_item_coffin
+      {
+        \vcoffin_set:Nnn \l__tasks_tmpa_coffin
+          { \l__tasks_item_width_dim }
+          { \__tasks_setup: #2 }
+        \__tasks_debug:n
+          {
+            \coffin_typeset:Nnnnn \l__tasks_tmpa_coffin
+              { l } { T } { 0pt } { 0pt }
+          }
+      }
+    % set the label box:
+    \hcoffin_set:Nn \l__tasks_label_coffin
+      {
+        \vcoffin_set:Nnn \l__tasks_tmpa_coffin
+          {
+            \l__tasks_label_width_dim
+            \bool_if:NT \l__tasks_debug_bool {-2\fboxrule }
+          }
+          {
+            \noindent
+            \tl_use:N \l__tasks_item_fill_left_tl
+            \strut #1
+            \tl_use:N \l__tasks_item_fill_right_tl
+          }
+        \__tasks_debug:n
+          {
+            \coffin_typeset:Nnnnn \l__tasks_tmpa_coffin
+              { l } { T } { 0pt } { 0pt }
+          }
+      }
+    % attach the label box at the left of the item box, shifted by
+    % \l__tasks_label_offset_dim :
+    \coffin_attach:NnnNnnnn
+      \l__tasks_item_coffin { l } { T }
+      \l__tasks_label_coffin { r } { T }
+      { - \l__tasks_label_offset_dim
+        % - \l__tasks_label_width_dim - \l__tasks_label_offset_dim
+      } { 0pt }
+    % when a new row starts enter vertical mode:
+    \int_compare:nNnT { \g__tasks_current_col_num_int } = { 1 }
+      { \skip_vertical:N \c_zero_skip }
+    % skip horizontally by \l__tasks_item_indent_dim
+    \noindent
+    \skip_horizontal:N \l__tasks_item_indent_dim
+    % typeset the item (with the attached label protruding to the left):
+    \coffin_typeset:Nnnnn \l__tasks_item_coffin
+      { l } { T } { 0pt } { 0pt }
+    \bool_if:nT
+      {
+        \l__tasks_item_full_line_bool ||
+        (
+          \l__tasks_item_rest_of_line_bool &&
+          \int_compare_p:nNn { \l__tasks_item_columns_int } = { 0 }
+        )
+      }
+      { \tasks_new_row: }
+    % are we between items in a row? The skip by \l__tasks_column_sep_dim :
+    \int_compare:nNnT
+      { \g__tasks_current_col_num_int } < { \l__tasks_columns_int }
+      { \skip_horizontal:N \l__tasks_column_sep_dim }
+    % if we ended a row and a new row is still to come skip vertically by
+    % \l__tasks_after_item_skip :
+    \bool_if:nT
+      {
+        ( \int_compare_p:nNn { \g__tasks_current_col_num_int } = { \l__tasks_columns_int } )
+        &&
+        ( \int_compare_p:n { \g__tasks_current_row_num_int != \l__tasks_rows_int } )
+      }
+      { \skip_vertical:N \l__tasks_after_item_skip }
+    % clean up:
+    \coffin_clear:N \l__tasks_item_coffin
+    \coffin_clear:N \l__tasks_label_coffin
+    \coffin_clear:N \l__tasks_tmpa_coffin
+    \bool_set_false:N \l__tasks_item_full_line_bool
+    \bool_set_false:N \l__tasks_item_rest_of_line_bool
+  }
+\cs_generate_variant:Nn \__tasks_task:nnwwwwww { VV }
+
+\cs_new_protected:Npn \__tasks_setup:
+  {
+    \dim_set:Nn \parskip { 0pt }
+    \skip_set:Nn \parfillskip { 0pt plus 1fil }
+    \dim_set_eq:NN \parskip \parsep
+    \dim_set_eq:NN \parindent \listparindent
+    \noindent
+    \strut
+  }
+
+\cs_new_protected:Npn \__tasks_gset_rows_num:NN #1#2
+  {
+    \int_gset:Nn \l__tasks_rows_int { \int_div_truncate:nn { #1 } { #2 } }
+    \int_compare:nNnT { \int_mod:nn { #1 } { #2 } } > { 0 }
+      { \int_gincr:N \l__tasks_rows_int }
+  }
+
+\cs_new_protected:Npn \__tasks_label_align:n #1
+  {
+    \clist_if_in:nnTF { left , center , right } { #1 }
+      {
+        \tl_if_eq:nnT { #1 } { left }
+          {
+            \tl_clear:N   \l__tasks_item_fill_left_tl
+            \tl_set_eq:NN \l__tasks_item_fill_right_tl \hfill
+          }
+        \tl_if_eq:nnT { #1 } { right }
+          {
+            \tl_set_eq:NN \l__tasks_item_fill_left_tl \hfill
+            \tl_clear:N   \l__tasks_item_fill_right_tl
+          }
+        \tl_if_eq:nnT { #1 } { center }
+          {
+            \tl_set_eq:NN \l__tasks_item_fill_left_tl  \hfill
+            \tl_set_eq:NN \l__tasks_item_fill_right_tl \hfill
+          }
+      }
+      {
+        \tl_clear:N   \l__tasks_item_fill_left_tl
+        \tl_set_eq:NN \l__tasks_item_fill_right_tl \hfill
+      }
+  }
+\cs_generate_variant:Nn \__tasks_label_align:n { V }
+\__tasks_label_align:n { left }
+
+% --------------------------------------------------------------------------
+% the `tasks' object:
+%   #1: number of items
+%   #2: number of columns
+%   #3: label-format
+\DeclareObjectType { tasks } { 3 }
+% the `default' template interface:
+\DeclareTemplateInterface { tasks } { default } { 3 }
+  {
+    enumerate       : boolean   = true    ,
+    label           : tokenlist           ,
+    indent          : length    = 2.5em   ,
+    counter-format  : tokenlist = tsk[a]) ,
+    label-format    : tokenlist ,
+    label-width     : length    = 1em     ,
+    label-offset    : length    = .3333em ,
+    after-item-skip : skip      = 1ex plus 1ex minus 1ex
+  }
+
+% in the next three commands we want a really unlikely to occur marker; for
+% this we use $ with unusual catcode in ``$tasks$default$label$'':
+\cs_set:Nx \__tasks_restore_dollar:
+  { \char_set_catcode:nn {36} { \char_value_catcode:n {36} } }
+\char_set_catcode_alignment:N \$
+
+% the `default' template code:
+\DeclareTemplateCode { tasks } { default } { 3 }
+  {
+    enumerate       = \l__tasks_enumerate_bool           ,
+    label           = \l__tasks_label_tl                 ,
+    indent          = \l__tasks_item_default_indent_dim  ,
+    counter-format  = \l__tasks_label_pattern_tl         ,
+    label-format    = \l__tasks_label_format_tl          ,
+    label-width     = \l__tasks_label_default_width_dim  ,
+    label-offset    = \l__tasks_label_default_offset_dim ,
+    after-item-skip = \l__tasks_after_item_skip
+  }
+  {
+    \AssignTemplateKeys
+    \bool_if:NF \l__tasks_label_width_bool
+      {
+        \dim_set_eq:NN
+          \l__tasks_label_width_dim
+          \l__tasks_label_default_width_dim
+      }
+    \bool_if:NF \l__tasks_item_indent_bool
+      {
+        \dim_set_eq:NN
+          \l__tasks_item_indent_dim
+          \l__tasks_item_default_indent_dim
+      }
+    \bool_if:NF \l__tasks_label_offset_bool
+      {
+        \dim_set_eq:NN
+          \l__tasks_label_offset_dim
+          \l__tasks_label_default_offset_dim
+      }
+    \dim_compare:nNnT
+      { \l__tasks_item_indent_dim }
+       <
+      { \l__tasks_label_offset_dim + \l__tasks_label_width_dim }
+      {
+        \dim_set:Nn \l__tasks_item_indent_dim
+          { \l__tasks_label_offset_dim + \l__tasks_label_width_dim }
+      }
+    \bool_if:NT \l__tasks_custom_after_item_skip_bool
+      {
+        \skip_set_eq:NN
+          \l__tasks_after_item_skip
+          \l__tasks_custom_after_item_skip
+      }
+    \bool_if:NT \l__tasks_custom_label_bool
+      {
+        \tl_set_eq:NN
+          \l__tasks_label_tl
+          \l__tasks_custom_label_tl
+        \bool_set_false:N \l__tasks_enumerate_bool
+      }
+    \__tasks_label_align:V \l__tasks_label_align_tl
+    % need this for enumerate list:
+    \bool_if:nT { !\l__tasks_resume_bool && \l__tasks_enumerate_bool }
+      { \int_gzero:N \g__tasks_int }
+    \int_set:Nn \l__tasks_columns_int { #2 }
+    % set all the items in their own coffins and join with the ground:
+    \int_gzero:N \g__tasks_current_col_num_int
+    \int_set:Nn \g__tasks_current_row_num_int { 1 }
+    \tl_if_blank:VF \l__tasks_custom_label_pattern_tl
+      {
+        \tl_set_eq:NN
+          \l__tasks_label_pattern_tl
+          \l__tasks_custom_label_pattern_tl
+      }
+    \tl_if_blank:VF \l__tasks_custom_label_format_tl
+      {
+        \tl_set_eq:NN
+          \l__tasks_label_format_tl
+          \l__tasks_custom_label_format_tl
+      }
+    \seq_map_inline:Nn \l__tasks_seq
+      {
+        \__tasks_read_item:www ##1 \q_stop
+        \bool_if:NTF \l__tasks_enumerate_bool
+          {
+            \tl_if_eq:VnT \l__tasks_tmp_label_tl { $tasks$default$label$ }
+              {
+                \int_gincr:N \g__tasks_int
+                \SaveCounterPatternFrom [ tasks ]
+                  \l__tasks_tmpa_tl
+                  \l__tasks_label_tl
+                  \l__tasks_label_pattern_tl
+                \cs_gset:Npx \@currentlabel { \l__tasks_label_tl }
+              }
+          }
+          {
+            \tl_if_blank:VT \l__tasks_label_tl
+              { \tl_set_eq:NN \l__tasks_label_tl \labelitemi }
+          }
+        \tl_put_left:NV \l__tasks_label_tl \l__tasks_label_format_tl
+        \tl_if_eq:VnTF \l__tasks_tmp_label_tl { $tasks$default$label$ }
+          {
+            \__tasks_task:VVwwwwww
+              \l__tasks_label_tl
+              \l__tasks_item_tl
+              [ l , b ] [ l , t ] ( 0pt , 0pt )
+          }
+          {
+            \__tasks_task:VVwwwwww
+              \l__tasks_tmp_label_tl
+              \l__tasks_item_tl
+              [ l , b ] [ l , t ] ( 0pt , 0pt )
+            \tl_clear:N \l__tasks_tmp_label_tl
+          }
+      }
+  }
+
+\cs_new_protected:Npn \__tasks_read_item:www
+  {
+    \peek_meaning_remove:NTF !
+      {
+        \bool_set_true:N \l__tasks_item_full_line_bool
+        \__tasks_read_item_aux:ww
+      }
+      {
+        \peek_meaning_remove:NTF *
+          {
+            \bool_set_true:N \l__tasks_item_rest_of_line_bool
+            \__tasks_read_item_rest_of_line:ww
+          }
+          { \__tasks_read_item_aux:ww }
+      }
+  }
+
+\cs_new_protected:Npn \__tasks_read_item_rest_of_line:ww
+  {
+    \peek_meaning:NTF ( % )
+      { \__tasks_read_item_rest_of_line_aux:ww }
+      { \__tasks_read_item_rest_of_line_aux:ww (0) }
+  }
+
+\cs_new_protected:Npn \__tasks_read_item_rest_of_line_aux:ww (#1)
+  {
+    \int_set:Nn \l__tasks_item_columns_int {#1}
+    \__tasks_read_item_aux:ww
+  }
+
+\cs_new_protected:Npn \__tasks_read_item_aux:ww
+  {
+    \peek_meaning:NTF [ % ]
+      { \__tasks_read_item_aux_ii:ww }
+      { \__tasks_read_item_aux_ii:ww [$tasks$default$label$] }
+  }
+
+\cs_new_protected:Npn \__tasks_read_item_aux_ii:ww [#1]#2 \q_stop
+  {
+    \tl_set:Nn \l__tasks_tmp_label_tl { #1 }
+    \tl_if_eq:nnF { #1 } { $tasks$default$label$ }
+      { \tl_put_left:NV \l__tasks_tmp_label_tl \l__tasks_label_format_tl }
+    \tl_set:Nn \l__tasks_item_tl { \ignorespaces #2 }
+  }
+
+\__tasks_restore_dollar:
+
+% --------------------------------------------------------------------------
+% choice box:
+\bool_new:N \l__tasks_choice_checked_bool
+\dim_new:N  \l__tasks_choice_width_dim
+\dim_set:Nn \l__tasks_choice_width_dim { 1.25ex }
+\dim_new:N  \l__tasks_choice_linewidth_dim
+\dim_set:Nn \l__tasks_choice_linewidth_dim { .3pt }
+\dim_new:N  \l__tasks_choice_checkwidth_dim
+\dim_set:Nn \l__tasks_choice_checkwidth_dim { .5pt }
+\dim_new:N  \l__tasks_choice_raise_dim
+\dim_set:Nn \l__tasks_choice_raise_dim { .1ex }
+
+\cs_new_protected:Npn \tasks_choice:
+  {
+    \leavevmode
+    \group_begin:
+      \bool_set_false:N \l__tasks_choice_checked_bool
+      \box_move_up:nn
+        { \l__tasks_choice_raise_dim }
+        { \hbox:n { \__tasks_choice: } }
+    \group_end:
+  }
+
+\cs_new_protected:Npn \tasks_choice_checked:
+  {
+    \leavevmode
+    \group_begin:
+      \bool_set_true:N \l__tasks_choice_checked_bool
+      \box_move_up:nn
+        { \l__tasks_choice_raise_dim }
+        { \hbox:n { \__tasks_choice: } }
+    \group_end:
+  }
+
+\cs_new_protected:Npn \__tasks_choice:
+  {%
+    \dim_set:Nn \unitlength { .1\l__tasks_choice_width_dim }
+    \begin{picture}(10,0)
+      \linethickness \l__tasks_choice_linewidth_dim
+      \drawline(0,0)(0,10)(10,10)(10,0)(0,0)
+      \linethickness \l__tasks_choice_checkwidth_dim
+      \bool_if:NT \l__tasks_choice_checked_bool
+        {
+          \drawline(2,2)(8,8)
+          \drawline(2,8)(8,2)
+        }
+    \end{picture}%
+  }
+
+\providecommand* \choicebox { \tasks_choice: }
+\providecommand* \checkedchoicebox { \tasks_choice_checked: }
+
+% --------------------------------------------------------------------------
+% base instance:
+% ALPHABETIZE: a) b) c)
+\DeclareInstance { tasks } { alphabetize } { default } { }
+
+\keys_define:nn { tasks / list }
+  {
+    debug           .bool_set:N = \l__tasks_debug_bool ,
+    style           .tl_set:N   = \l__tasks_instance_tl ,
+    counter-format  .tl_set:N   = \l__tasks_custom_label_pattern_tl ,
+    label           .code:n     =
+      \bool_set_true:N \l__tasks_custom_label_bool
+      \tl_set:Nn \l__tasks_custom_label_tl { #1 } ,
+    label-format    .tl_set:N   = \l__tasks_custom_label_format_tl ,
+    label-width     .code:n     =
+      \dim_set:Nn \l__tasks_label_width_dim { #1 }
+      \bool_set_true:N \l__tasks_label_width_bool ,
+    label-offset    .code:n     =
+      \dim_set:Nn \l__tasks_label_offset_dim { #1 }
+      \bool_set_true:N \l__tasks_label_offset_bool ,
+    label-align     .tl_set:N   = \l__tasks_label_align_tl ,
+    item-indent     .code:n     =
+      \dim_set:Nn \l__tasks_item_indent_dim { #1 }
+      \bool_set_true:N \l__tasks_item_indent_bool ,
+    columns-sep     .dim_set:N  = \l__tasks_column_sep_dim ,
+    before-skip     .skip_set:N = \l__tasks_before_list_skip ,
+    after-skip      .skip_set:N = \l__tasks_after_list_skip ,
+    after-item-skip .code:n     =
+      \bool_set_true:N \l__tasks_custom_after_item_skip_bool
+      \skip_set:Nn \l__tasks_custom_after_item_skip { #1 } ,
+    resume          .bool_set:N = \l__tasks_resume_bool
+  }
+
+% --------------------------------------------------------------------------
+% the generic environment:
+\NewEnviron { __tasks_env: } [ 3 ]
+  {
+    \keys_set:nn { tasks / list } { #2 }
+    \tl_if_blank:VT \l__tasks_instance_tl
+      { \keys_set:nn { tasks / list } { style = alphabetize } }
+    \skip_vertical:N \l__tasks_before_list_skip
+    \skip_vertical:N \c_zero_skip
+    \list {}
+      {
+        \dim_set:Nn \leftmargin { 0pt }
+        \dim_set:Nn \rightmargin { 0pt }
+      }
+    \item \scan_stop:
+    \int_incr:N \l__tasks_depth_int
+    \__tasks:VnnV \l__tasks_instance_tl { #3 } { #1 } \BODY
+    \endlist
+    \skip_vertical:N \l__tasks_after_list_skip
+  }
+
+% --------------------------------------------------------------------------
+% command to start a new row:
+\cs_new_protected:Npn \tasks_new_row:
+  {
+    \int_gset:Nn \g__tasks_total_items_int
+      { \g__tasks_total_items_int + \l__tasks_columns_int - \g__tasks_current_col_num_int }
+    \__tasks_gset_rows_num:NN
+      \g__tasks_total_items_int
+      \l__tasks_columns_int
+    \int_gset_eq:NN \g__tasks_current_col_num_int \l__tasks_columns_int
+  }
+
+\NewDocumentCommand \startnewitemline {}
+  { \tasks_new_row: }
+
+% --------------------------------------------------------------------------
+% the user environment:
+\NewDocumentCommand \NewTasks { O{}mO{\task}D(){1} }
+  {
+    \NewDocumentEnvironment { #2 } { O{}D(){#4} }
+      { \__tasks_env: { #3 } { #1,##1 } { ##2 } }
+      { \end__tasks_env: }
+  }
+
+\NewDocumentCommand \RenewTasks { O{}mO{\task}D(){1} }
+  {
+    \RenewDocumentEnvironment { #2 } { O{}D(){#4} }
+      { \__tasks_env: { #3 } { #1,##1 } { ##2 } }
+      { \end__tasks_env: }
+  }
+
+% --------------------------------------------------------------------------
+% default list:
+\NewTasks { tasks }
+
+% --------------------------------------------------------------------------
+% package options:
+\keys_define:nn { tasks / options }
+  {
+    more .code:n = \msg_warning:nnn {tasks} {deprecated-option} {more}
+  }
+
+\ProcessKeysOptions { tasks / options }
+
+\cs_if_exist:NF \tasks_config_file_loaded:
+  { \file_input:n { tasks.cfg } }
+
+% --------------------------------------------------------------------------
+% setup:
+\cs_new_protected:Npn \tasks_setup:n #1
+  { \keys_set:nn { tasks / list } { #1 } }
+
+\NewDocumentCommand \settasks { m }
+  { \tasks_setup:n { #1 } }
+
+% --------------------------------------------------------------------------
+\tex_endinput:D
+
+% HISTORY:
+2013/01/19 v0.7   - extracted from `exsheets' package; this also lead to a
+                    slightly new syntax and a few new options for it
+2013/04/04 v0.8a  - corrected \seq_length:N => \seq_count:N
+2013/04/07 v0.9   - protected internal commands where appropriate
+                  - made enumerated item referenceable with \label{}
+                    and \ref{}; this introduced new options:
+                     * the former `label-format' is now `counter-format'
+                     * new: `label-format'
+                  - changed defaults for `label-width' and `label-offset'
+                  - ensure that the `after-item-skip' is only
+                          inserted in between rows
+                  - new option `after-item-skip'
+                  - improvements when label are set with optional argument:
+                     * a provided but empty argument is now correctly recognized
+                     * the counter is  _not_ stepped anymore for enumerated
+                       lists when the optional argument is provided
+                  - new command \startnewitemline that forces the next item to
+                    be put at the beginning of a row
+2013/04/22 v0.9a  - new option `item-indent'
+                  - synchronized version number with `exsheets' until now but
+                    won't any more
+2013/12/03 v0.9b  - add missing \noindent for the case when \listparindent is
+                    non-zero, fixes http://tex.stackexchange.com/q/148082/5049
+2014/05/11 v0.9c  - remove definition of the \task macro: it is not necessary
+                    for `tasks' to function but it conflicts e.g. with `ltxdoc'
+                    class
+2014/07/11 v0.20  - new option `debug'
+                  - new option `column-sep
+                  - renamed a few internal variables
+                  - remove package from the `exsheets' bundle and distribute
+                    it as package of its own
+                  - new: optional bang to a \task forces an item to use a full
+                    line (\task!)
+                  - new: optional star to a \task forces an item to use the
+                    complete remaining line (\task*); the star has itself has
+                    an optional argument for specifying the number of columns
+                    to span (\task*(<num>))