% \iffalse
%% File: l3calc.dtx Copyright (C) 2006 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 ``expl3 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/cgi-bin/cvsweb.cgi/
%%
%% 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
%%   prior consultation with the LaTeX Project Team.
%%
%% -----------------------------------------------------------------------
%<package>\RequirePackage{l3names}
%<*dtx>
%\fi
\def\GetIdInfo$Id: #1.dtx #2 #3-#4-#5 #6 #7$#8{%
  \def\fileversion{#2}%
  \def\filedate{#3/#4/#5}%
  \ProvidesFile{#1.dtx}[#3/#4/#5 v#2 #8]%
}
%\iffalse
%</dtx>
%\fi
\GetIdInfo$Id: l3calc.dtx 573 2006-08-21 20:59:37Z morten $
       {L3 Experimental calc module}
% \iffalse
%<*driver>
\documentclass{l3doc}

\begin{document}
\DocInput{l3calc.dtx}
\end{document}
%</driver>
% \fi
%
% \title{The \textsf{l3calc} package\thanks{This file has version
%     number \fileversion, last
%     revised \filedate.}\\
%   Infix notation arithmetic in \LaTeX3} 
% \author{\Team}
% \date{\filedate}
% \maketitle
%
% \section{Infix notation arithmetic}
% 
% This is pretty much a straight adaption of the \textsf{calc} package
% and as such has same syntax for the \meta{calc expression}. However,
% there are some noticeable differences.
% \begin{itemize}
% \item The calc expression is expanded fully, which means there are
%   no problems with unfinished conditionals. However, the contents of
%   |\widthof| etc.\ is not expanded at all.
% \item Muskip registers are supported although they can only be used
%   in |\ratio| if already evaluating a muskip expression. For the
%   other three register types, you can use points.
% \item All results are rounded, not truncated. More precisely, the
%   primitive \TeX\ operations |\divide| and |\multiply| are not used.
% \end{itemize}
%
% \begin{function}{
%     \calc_int_set:Nn |
%     \calc_int_gset:Nn |
%     \calc_int_add:Nn |
%     \calc_int_gadd:Nn |
%     \calc_int_sub:Nn |
%     \calc_int_gsub:Nn |
% }
%   \begin{syntax}
%     "\calc_int_set:Nn" <int> "{"<calc expression>"}"
%   \end{syntax}
%   Evaluates <calc expression> and either adds or subtracts it from
%   <int> or sets <int> to it. These operations can also be global.
% \end{function}
%
%
% \begin{function}{
%     \calc_dim_set:Nn |
%     \calc_dim_gset:Nn |
%     \calc_dim_add:Nn |
%     \calc_dim_gadd:Nn |
%     \calc_dim_sub:Nn |
%     \calc_dim_gsub:Nn |
% }
%   \begin{syntax}
%     "\calc_dim_set:Nn" <dim> "{"<calc expression>"}"
%   \end{syntax}
%   Evaluates <calc expression> and either adds or subtracts it from
%   <dim> or sets <dim> to it. These operations can also be global.
% \end{function}
%
%
% \begin{function}{
%     \calc_skip_set:Nn |
%     \calc_skip_gset:Nn |
%     \calc_skip_add:Nn |
%     \calc_skip_gadd:Nn |
%     \calc_skip_sub:Nn |
%     \calc_skip_gsub:Nn |
% }
%   \begin{syntax}
%     "\calc_skip_set:Nn" <skip> "{"<calc expression>"}"
%   \end{syntax}
%   Evaluates <calc expression> and either adds or subtracts it from
%   <skip> or sets <skip> to it. These operations can also be global.
% \end{function}
%
%
% \begin{function}{
%     \calc_muskip_set:Nn |
%     \calc_muskip_gset:Nn |
%     \calc_muskip_add:Nn |
%     \calc_muskip_gadd:Nn |
%     \calc_muskip_sub:Nn |
%     \calc_muskip_gsub:Nn |
% }
%   \begin{syntax}
%     "\calc_muskip_set:Nn" <muskip> "{"<calc expression>"}"
%   \end{syntax}
%   Evaluates <calc expression> and either adds or subtracts it from
%   <muskip> or sets <muskip> to it. These operations can also be
%   global.
% \end{function}
%
%
% \begin{function}{
%     \calc_calculate_box_size:nnn |
% }
%   \begin{syntax}
%     "\calc_calculate_box_size:nnn" "{"<dim-set>"}" \\
%     "{"<item 1> <item 2> ... <item n>"}" "{"<contents>"}"
%   \end{syntax}
%   Sets <contents> in a temporary box "\l_tmpa_box". Then <dim-set>
%   is put in front of a loop that inserts "+"\meta{item$\sb{i}$} in
%   front of "\l_tmpa_box" and this is evaluated.  For instance, if we
%   wanted to determine the total height of the text "xyz" and store
%   it in "\l_tmpa_dim", we would call it as.
% \begin{verbatim}
% \calc_calculate_box_size:nnn 
%   {\dim_set:Nn\l_tmpa_dim}{\box_ht:N\box_dp:N}{xyz}
% \end{verbatim}
%   Similarly, if we wanted the difference between height and depth,
%   we could call it as
% \begin{verbatim}
% \calc_calculate_box_size:nnn 
%   {\dim_set:Nn\l_tmpa_dim}{\box_ht:N{-\box_dp:N}}{xyz}
% \end{verbatim}
% \end{function}
%
% \StopEventually{}
%
% \subsection{The Implementation}
%
% Since this is basically a re-worked version of the \textsf{calc}
% package, I haven't bothered with too many comments except for in the
% places where this package differs. This may (and should) change at
% some point.
%
% We start by ensuring that the required packages are loaded.
%    \begin{macrocode}
%<*package>
\RequirePackage{l3int}
\RequirePackage{l3skip}
\RequirePackage{l3box}
%</package>
%<*initex|package>
%    \end{macrocode}
%
%
% \begin{macro}{\l_calc_expression_tlp}
% \begin{macro}{\g_calc_A_register}
% \begin{macro}{\l_calc_B_register}
% \begin{macro}{\l_calc_current_type_int}
% Here we define some registers and pointers we will need.
%    \begin{macrocode}
\tlp_new:Nn\l_calc_expression_tlp{}
\def_new:Npn \g_calc_A_register{}
\def_new:Npn \l_calc_B_register{}
\int_new:N \l_calc_current_type_int
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\g_calc_A_int}
% \begin{macro}{\l_calc_B_int}
% \begin{macro}{\l_calc_C_int}
% \begin{macro}{\g_calc_A_dim}
% \begin{macro}{\l_calc_B_dim}
% \begin{macro}{\l_calc_C_dim}
% \begin{macro}{\g_calc_A_skip}
% \begin{macro}{\l_calc_B_skip}
% \begin{macro}{\l_calc_C_skip}
% \begin{macro}{\g_calc_A_muskip}
% \begin{macro}{\l_calc_B_muskip}
% \begin{macro}{\l_calc_C_muskip}
%   For each type of register we will need three registers to do our
%   manipulations.
%    \begin{macrocode}
\int_new:N \g_calc_A_int
\int_new:N \l_calc_B_int
\int_new:N \l_calc_C_int
\dim_new:N \g_calc_A_dim
\dim_new:N \l_calc_B_dim
\dim_new:N \l_calc_C_dim
\skip_new:N \g_calc_A_skip
\skip_new:N \l_calc_B_skip
\skip_new:N \l_calc_C_skip
\muskip_new:N \g_calc_A_muskip
\muskip_new:N \l_calc_B_muskip
\muskip_new:N \l_calc_C_muskip
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
%
%
% \begin{macro}{\calc_assign_generic:NNNNNn}
%   The generic function. |#1| is a number denoting which type we are
%   doing. (0=int, 1=dim, 2=skip, 3=muskip), |#2| = temp register A,
%   |#3| = temp register B, |#4| is a function acting on |#5| which is
%   the register to be set. |#6| is the calc expression.  This version
%   relies on |\real| and |\ratio| having our definitions.
%    \begin{macrocode}
\def_long_new:Npn \calc_assign_generic:NNNNNn#1#2#3#4#5#6{
  \let:NN\g_calc_A_register#2\let:NN\l_calc_B_register#3
  \int_set:Nn \l_calc_current_type_int {#1}
  \tlp_set:Nx\l_calc_expression_tlp{#6}
  \exp_after:NN\calc_open:w\exp_after:NN(\l_calc_expression_tlp!
  \pref_global:D\g_calc_A_register\l_calc_B_register
  \group_end:
  #4#5\l_calc_B_register
}
%    \end{macrocode}
% One could lift these restrictions by defining |\calc_generic:NNNNNn|
% like this:
% \begin{verbatim}
% \def_long_new:Npn \calc_assign_generic:NNNNNn#1#2#3#4#5#6{
%   \let:NN\g_calc_A_register#2\let:NN\l_calc_B_register#3
%   \int_set:Nn \l_calc_current_type_int {#1}
%   \group_begin:
%     \let:NN \real\calc_real:n
%     \let:NN \ratio\calc_ratio:nn
%     \tlp_set:Nx\l_calc_expression_tlp{#6}
%     \exp_after:NN
%   \group_end:
%   \exp_after:NN\calc_open:w\exp_after:NN(\l_calc_expression_tlp!
%   \pref_global:D\g_calc_A_register\l_calc_B_register
%   \group_end:
%   #4#5\l_calc_B_register
% }
% \end{verbatim}
% \end{macro}
%
%
%
% \begin{macro}{\calc_int_set:Nn}
% \begin{macro}{\calc_int_gset:Nn}
% \begin{macro}{\calc_int_add:Nn}
% \begin{macro}{\calc_int_gadd:Nn}
% \begin{macro}{\calc_int_sub:Nn}
% \begin{macro}{\calc_int_gsub:Nn}
%   Here are the individual versions for the different register
%   types. First integer registers.
%    \begin{macrocode}
\def_new:Npn\calc_int_set:Nn{
  \calc_assign_generic:NNNNNn\c_zero\g_calc_A_int\l_calc_B_int\int_set:Nn
}
\def_new:Npn\calc_int_gset:Nn{
  \calc_assign_generic:NNNNNn\c_zero\g_calc_A_int\l_calc_B_int\int_gset:Nn
}
\def_new:Npn\calc_int_add:Nn{
  \calc_assign_generic:NNNNNn\c_zero\g_calc_A_int\l_calc_B_int\int_add:Nn
}
\def_new:Npn\calc_int_gadd:Nn{
  \calc_assign_generic:NNNNNn\c_zero\g_calc_A_int\l_calc_B_int\int_gadd:Nn
}
\def_new:Npn\calc_int_sub:Nn{
  \calc_assign_generic:NNNNNn\c_zero\g_calc_A_int\l_calc_B_int\int_sub:Nn
}
\def_new:Npn\calc_int_gsub:Nn{
  \calc_assign_generic:NNNNNn\c_zero\g_calc_A_int\l_calc_B_int\int_gsub:Nn
}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_dim_set:Nn}
% \begin{macro}{\calc_dim_gset:Nn}
% \begin{macro}{\calc_dim_add:Nn}
% \begin{macro}{\calc_dim_gadd:Nn}
% \begin{macro}{\calc_dim_sub:Nn}
% \begin{macro}{\calc_dim_gsub:Nn}
%   Dimens.
%    \begin{macrocode}
\def_new:Npn\calc_dim_set:Nn{
  \calc_assign_generic:NNNNNn\c_one\g_calc_A_dim\l_calc_B_dim\dim_set:Nn
}
\def_new:Npn\calc_dim_gset:Nn{
  \calc_assign_generic:NNNNNn\c_one\g_calc_A_dim\l_calc_B_dim\dim_gset:Nn
}
\def_new:Npn\calc_dim_add:Nn{
  \calc_assign_generic:NNNNNn\c_one\g_calc_A_dim\l_calc_B_dim\dim_add:Nn
}
\def_new:Npn\calc_dim_gadd:Nn{
  \calc_assign_generic:NNNNNn\c_one\g_calc_A_dim\l_calc_B_dim\dim_gadd:Nn
}
\def_new:Npn\calc_dim_sub:Nn{
  \calc_assign_generic:NNNNNn\c_one\g_calc_A_int\l_calc_B_int\dim_sub:Nn
}
\def_new:Npn\calc_dim_gsub:Nn{
  \calc_assign_generic:NNNNNn\c_one\g_calc_A_int\l_calc_B_int\dim_gsub:Nn
}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_skip_set:Nn}
% \begin{macro}{\calc_skip_gset:Nn}
% \begin{macro}{\calc_skip_add:Nn}
% \begin{macro}{\calc_skip_gadd:Nn}
% \begin{macro}{\calc_skip_sub:Nn}
% \begin{macro}{\calc_skip_gsub:Nn}
%   Skips.
%    \begin{macrocode}
\def_new:Npn\calc_skip_set:Nn{
  \calc_assign_generic:NNNNNn\c_two\g_calc_A_dim\l_calc_B_dim\skip_set:Nn
}
\def_new:Npn\calc_skip_gset:Nn{
  \calc_assign_generic:NNNNNn\c_two\g_calc_A_dim\l_calc_B_dim\skip_gset:Nn
}
\def_new:Npn\calc_skip_add:Nn{
  \calc_assign_generic:NNNNNn\c_two\g_calc_A_dim\l_calc_B_dim\skip_add:Nn
}
\def_new:Npn\calc_skip_gadd:Nn{
  \calc_assign_generic:NNNNNn\c_two\g_calc_A_dim\l_calc_B_dim\skip_gadd:Nn
}
\def_new:Npn\calc_skip_sub:Nn{
  \calc_assign_generic:NNNNNn\c_two\g_calc_A_dim\l_calc_B_dim\skip_sub:Nn
}
\def_new:Npn\calc_skip_gsub:Nn{
  \calc_assign_generic:NNNNNn\c_two\g_calc_A_dim\l_calc_B_dim\skip_gsub:Nn
}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_muskip_set:Nn}
% \begin{macro}{\calc_muskip_gset:Nn}
% \begin{macro}{\calc_muskip_add:Nn}
% \begin{macro}{\calc_muskip_gadd:Nn}
% \begin{macro}{\calc_muskip_sub:Nn}
% \begin{macro}{\calc_muskip_gsub:Nn}
%   Muskips.
%    \begin{macrocode}
\def_new:Npn\calc_muskip_set:Nn{
  \calc_assign_generic:NNNNNn\c_three\g_calc_A_dim\l_calc_B_dim\muskip_set:Nn
}
\def_new:Npn\calc_muskip_gset:Nn{
  \calc_assign_generic:NNNNNn\c_three\g_calc_A_dim\l_calc_B_dim\muskip_gset:Nn
}
\def_new:Npn\calc_muskip_add:Nn{
  \calc_assign_generic:NNNNNn\c_three\g_calc_A_dim\l_calc_B_dim\muskip_add:Nn
}
\def_new:Npn\calc_muskip_gadd:Nn{
  \calc_assign_generic:NNNNNn\c_three\g_calc_A_dim\l_calc_B_dim\muskip_gadd:Nn
}
\def_new:Npn\calc_muskip_sub:Nn{
  \calc_assign_generic:NNNNNn\c_three\g_calc_A_dim\l_calc_B_dim\muskip_add:Nn
}
\def_new:Npn\calc_muskip_gsub:Nn{
  \calc_assign_generic:NNNNNn\c_three\g_calc_A_dim\l_calc_B_dim\muskip_gadd:Nn
}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
%
% \begin{macro}{\calc_pre_scan:N}
%   In case we found one of the special operations, this should just
%   be executed.
% \begin{macrocode}
\def_new:Npn \calc_pre_scan:N #1{
  \if_meaning:NN(#1
    \exp_after:NN\calc_open:w
  \else:
    \if_meaning:NN \calc_textsize:Nn #1
    \else:
      \if_meaning:NN \calc_maxmin_operation:Nnn #1
      \else:
%    \end{macrocode}
% |\calc_numeric:| uses a primitive assignment so doesn't care about
% these dangling |\fi:|s.
%    \begin{macrocode}
        \calc_numeric:
      \fi:      
    \fi:
  \fi:
  #1}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\calc_open:w}
%    \begin{macrocode}
\def_new:Npn \calc_open:w({
  \group_begin:\group_execute_after:N\calc_init_B:
  \group_begin:\group_execute_after:N\calc_init_B:
  \calc_pre_scan:N
}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\calc_init_B:}
% \begin{macro}{\calc_numeric:}
% \begin{macro}{\calc_close:}
%    \begin{macrocode}
\def_new:Npn\calc_init_B:{\l_calc_B_register\g_calc_A_register}
\def_new:Npn\calc_numeric:{
  \tex_afterassignment:D\calc_post_scan:N 
  \pref_global:D\g_calc_A_register
}
\def_new:Npn\calc_close:{
  \group_end:\pref_global:D\g_calc_A_register\l_calc_B_register
  \group_end:\pref_global:D\g_calc_A_register\l_calc_B_register
  \calc_post_scan:N}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_post_scan:N}
% Look at what token we have and decide where to go.
%    \begin{macrocode}
\def_new:Npn\calc_post_scan:N#1{
  \if_meaning:NN#1!\let:NN\calc_next:w\group_end: \else:
    \if_meaning:NN#1+\let:NN\calc_next:w\calc_add: \else:
      \if_meaning:NN#1-\let:NN\calc_next:w\calc_subtract: \else:
        \if_meaning:NN#1*\let:NN\calc_next:w\calc_multiply:N \else:
          \if_meaning:NN#1/\let:NN\calc_next:w\calc_divide:N \else:
            \if_meaning:NN#1)\let:NN\calc_next:w\calc_close: \else:
%    \end{macrocode}
% If we get here, there is an error but let's also disable
% |\calc_next:w| since it is otherwise undefined. No need to give
% extra errors just for that.
%    \begin{macrocode}
              \let:NN \calc_next:w \scan_stop:
              \calc_error:N#1
            \fi:
          \fi:
        \fi:
      \fi:
    \fi:
  \fi:
  \calc_next:w}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\calc_multiply:N}
% \begin{macro}{\calc_divide:N}
% The switches for multiplication and division.
%    \begin{macrocode}
\def_new:Npn \calc_multiply:N #1{
  \if_meaning:NN \calc_maxmin_operation:Nnn #1
    \let:NN \calc_next:w \calc_maxmin_multiply:
  \else:
    \if_meaning:NN \calc_ratio_multiply:nn #1
      \let:NN \calc_next:w \calc_ratio_multiply:nn
    \else:
      \if_meaning:NN \calc_real_evaluate:nn #1
        \let:NN \calc_next:w \calc_real_multiply:n
      \else:
        \def:Npn \calc_next:w{\calc_multiply: #1}
      \fi:
    \fi:
  \fi:
  \calc_next:w 
}
\def_new:Npn \calc_divide:N #1{
  \if_meaning:NN \calc_maxmin_operation:Nnn #1
    \let:NN \calc_next:w \calc_maxmin_divide:
  \else:
    \if_meaning:NN \calc_ratio_multiply:nn #1
      \let:NN \calc_next:w \calc_ratio_divide:nn
    \else:
      \if_meaning:NN \calc_real_evaluate:nn #1
        \let:NN \calc_next:w \calc_real_divide:n
      \else:
        \def:Npn \calc_next:w{\calc_divide: #1}
      \fi:
    \fi:
  \fi:
  \calc_next:w
}
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_generic_add:N}
% \begin{macro}{\calc_add:}
% \begin{macro}{\calc_subtract:}
% \begin{macro}{\calc_add_A_to_B:}
% \begin{macro}{\calc_subtract_A_from_B:}
% Here is how we add and subtract.
%    \begin{macrocode}
\def_new:Npn\calc_generic_add_or_subtract:N#1{
  \group_end:
  \pref_global:D\g_calc_A_register\l_calc_B_register\group_end:
  \group_begin:\group_execute_after:N#1\group_begin:
  \group_execute_after:N\calc_init_B:
  \calc_pre_scan:N}
\def_new:Npn\calc_add:{\calc_generic_add_or_subtract:N\calc_add_A_to_B:}
\def_new:Npn\calc_subtract:{
  \calc_generic_add_or_subtract:N\calc_subtract_A_from_B:}
%    \end{macrocode}
% Don't use |\tex_advance:D| since it allows overflows.
%    \begin{macrocode}
\def_new:Npn\calc_add_A_to_B:{
  \l_calc_B_register
  \if_case:w\l_calc_current_type_int
  \etex_numexpr:D\or:
  \etex_dimexpr:D\or:
  \etex_glueexpr:D\or:
  \etex_muexpr:D\fi:
  \l_calc_B_register + \g_calc_A_register\scan_stop:
}
\def_new:Npn\calc_subtract_A_from_B:{
  \l_calc_B_register
  \if_case:w\l_calc_current_type_int
  \etex_numexpr:D\or:
  \etex_dimexpr:D\or:
  \etex_glueexpr:D\or:
  \etex_muexpr:D\fi:
  \l_calc_B_register - \g_calc_A_register\scan_stop:
}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_generic_multiply_or_divide:N}
% \begin{macro}{\calc_multiply_B_by_A:}
% \begin{macro}{\calc_divide_B_by_A:}
% \begin{macro}{\calc_multiply:}
% \begin{macro}{\calc_divide:}
% And here is how we multiply and divide. Note that we do not use the
% primitive \TeX{} operations but the expandable operations provided
% by \eTeX. This means that all results are rounded not truncated!
%    \begin{macrocode}
\def_new:Npn\calc_generic_multiply_or_divide:N#1{
  \group_end:
  \group_begin:
  \let:NN\g_calc_A_register\g_calc_A_int 
  \let:NN\l_calc_B_register\l_calc_B_int
  \group_execute_after:N#1\calc_pre_scan:N
}
\def_new:Npn\calc_multiply_B_by_A:{
  \l_calc_B_register
  \if_case:w\l_calc_current_type_int
  \etex_numexpr:D\or:
  \etex_dimexpr:D\or:
  \etex_glueexpr:D\or:
  \etex_muexpr:D\fi:
  \l_calc_B_register*\g_calc_A_int\scan_stop:
}
\def_new:Npn\calc_divide_B_by_A:{
  \l_calc_B_register
  \if_case:w\l_calc_current_type_int
  \etex_numexpr:D\or:
  \etex_dimexpr:D\or:
  \etex_glueexpr:D\or:
  \etex_muexpr:D\fi:
  \l_calc_B_register/\g_calc_A_int\scan_stop:
}
\def_new:Npn\calc_multiply:{
  \calc_generic_multiply_or_divide:N\calc_multiply_B_by_A:}
\def_new:Npn\calc_divide:{
  \calc_generic_multiply_or_divide:N\calc_divide_B_by_A:}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_calculate_box_size:nnn}
% \begin{macro}{\calc_calculate_box_size_aux:n}
%   Put something in a box and measure it. |#1| is a list of
%   |\box_ht:N| etc., |#2| should be |\dim_set:Nn|\meta{dim register}
%   or |\dim_gset:Nn|\meta{dim register} and |#3| is the contents.
%    \begin{macrocode}
\def_long_new:Npn \calc_calculate_box_size:nnn #1#2#3{
  \hbox_set:Nn \l_tmpa_box {{#3}}
  #2{\c_zero_dim \tlist_map_function:nN{#1}\calc_calculate_box_size_aux:n}
}
%    \end{macrocode}
% Helper for calculating the final dimension.
%    \begin{macrocode}
\def:Npn \calc_calculate_box_size_aux:n#1{ + #1\l_tmpa_box}
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
%
% \begin{macro}{\calc_textsize:Nn}
% Now we can define |\calc_textsize:Nn|.
%    \begin{macrocode}
\def_protected_long:Npn \calc_textsize:Nn#1#2{
  \group_begin:
  \let:NN\widthof\box_wd:N
  \let:NN\heightof\box_ht:N
  \let:NN\depthof\box_dp:N	
  \def:Npn\totalheightof{\box_ht:N\box_dp:N}
  \exp_args:No\calc_calculate_box_size:nnn{#1}
  {\dim_gset:Nn\g_calc_A_register}
%    \end{macrocode}
% Restore the four user commands here since there might be a recursive
% call.
%    \begin{macrocode} 
  {
    \let:NN \depthof\calc_depthof:n
    \let:NN \widthof\calc_widthof:n
    \let:NN \heightof\calc_heightof:n
    \let:NN \totalheightof\calc_totalheightof:n
    #2
  }
  \group_end:
  \calc_post_scan:N
}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\calc_ratio_multiply:nn}
% \begin{macro}{\calc_ratio_divide:nn}
% Evaluate a ratio. If we were already evaluation a \meta{muskip}
% register, the ratio is probably also done with this type and we'll
% have to convert them to regular points.
%    \begin{macrocode}
\def_protected_long:Npn\calc_ratio_multiply:nn#1#2{
  \group_end:\group_begin:
  \if_num:w\l_calc_current_type_int < \c_three 
    \calc_dim_set:Nn\l_calc_B_int{#1}
    \calc_dim_set:Nn\l_calc_C_int{#2}
  \else: 
    \calc_dim_muskip:Nn{\l_calc_B_int\etex_mutoglue:D}{#1}
    \calc_dim_muskip:Nn{\l_calc_C_int\etex_mutoglue:D}{#2}
  \fi:
%    \end{macrocode}
% Then store the ratio as a fraction, which we just pass on. 
%    \begin{macrocode}
  \gdef:Npx\calc_calculated_ratio:{
    \int_use:N\l_calc_B_int/\int_use:N\l_calc_C_int
  }
  \group_end:
%    \end{macrocode}
% Here we set the new value of |\l_calc_B_register| and remember to
% evaluate it as the correct type. Note that the intermediate
% calculation is a scaled operation (meaning the intermediate value is
% 64-bit) so we don't get into trouble when first multiplying by a
% large number and then dividing.
%    \begin{macrocode}
  \l_calc_B_register
  \if_case:w\l_calc_current_type_int
  \etex_numexpr:D\or:
  \etex_dimexpr:D\or:
  \etex_glueexpr:D\or:
  \etex_muexpr:D\fi:
  \l_calc_B_register*\calc_calculated_ratio:\scan_stop:
  \group_begin:
  \calc_post_scan:N}
%    \end{macrocode}
% Division is just flipping the arguments around.
%    \begin{macrocode}
\def_long_new:Npn \calc_ratio_divide:nn#1#2{\calc_ratio_multiply:nn{#2}{#1}}
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_real_evaluate:nn}
% \begin{macro}{\calc_real_multiply:n}
% \begin{macro}{\calc_real_divide:n}
% Although we could define the |\real| function as a subcase of
% |\ratio|, this is horribly inefficient since we just want to convert
% the decimal to a fraction.
%    \begin{macrocode}
\def_protected_new:Npn\calc_real_evaluate:nn #1#2{
  \group_end:
  \l_calc_B_register
  \if_case:w\l_calc_current_type_int
  \etex_numexpr:D\or:
  \etex_dimexpr:D\or:
  \etex_glueexpr:D\or:
  \etex_muexpr:D\fi:
  \l_calc_B_register * 
    \tex_number:D \dim_eval:n{#1pt}/
    \tex_number:D\dim_eval:n{#2pt}
  \scan_stop:
  \group_begin:
  \calc_post_scan:N}
\def_new:Npn \calc_real_multiply:n #1{\calc_real_evaluate:nn{#1}{1}}
\def_new:Npn \calc_real_divide:n {\calc_real_evaluate:nn{1}}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_maxmin_operation:Nnn}
% \begin{macro}{\calc_maxmin_generic:Nnn}
% \begin{macro}{\calc_maxmin_div_or_mul:NNnn}
% \begin{macro}{\calc_maxmin_multiply:}
% \begin{macro}{\calc_maxmin_multiply:}
% The max and min functions.
%    \begin{macrocode}
\def_protected_long:Npn\calc_maxmin_operation:Nnn#1#2#3{
  \group_begin:
  \calc_maxmin_generic:Nnn#1{#2}{#3}
  \group_end:
  \calc_post_scan:N
}
%    \end{macrocode}
% |#1| is either |>| or |<| and was expanded into this initially.
%    \begin{macrocode}
\def_protected_long_new:Npn \calc_maxmin_generic:Nnn#1#2#3{
  \group_begin:
  \if_case:w\l_calc_current_type_int
    \calc_int_set:Nn\l_calc_C_int{#2}%
    \calc_int_set:Nn\l_calc_B_int{#3}%
    \pref_global:D\g_calc_A_register
    \if_num:w\l_calc_C_int#1\l_calc_B_int
    \l_calc_C_int\else:\l_calc_B_int\fi:
  \or:
    \calc_dim_set:Nn\l_calc_C_dim{#2}%
    \calc_dim_set:Nn\l_calc_B_dim{#3}%
    \pref_global:D\g_calc_A_register
    \if_dim:w\l_calc_C_dim#1\l_calc_B_dim
    \l_calc_C_dim\else:\l_calc_B_dim\fi:
  \or:
    \calc_skip_set:Nn\l_calc_C_skip{#2}%
    \calc_skip_set:Nn\l_calc_B_skip{#3}%
    \pref_global:D\g_calc_A_register
    \if_dim:w\l_calc_C_skip#1\l_calc_B_skip
    \l_calc_C_skip\else:\l_calc_B_skip\fi:
  \else:
    \calc_muskip_set:Nn\l_calc_C_muskip{#2}%
    \calc_muskip_set:Nn\l_calc_B_muskip{#3}%
    \pref_global:D\g_calc_A_register
    \if_dim:w\l_calc_C_muskip#1\l_calc_B_muskip
    \l_calc_C_muskip\else:\l_calc_B_muskip\fi:
  \fi:
  \group_end:
}
\def_long_new:Npn\calc_maxmin_div_or_mul:NNnn#1#2#3#4{
  \group_end:
  \group_begin:
  \int_zero:N\l_calc_current_type_int
  \group_execute_after:N#1
  \calc_maxmin_generic:Nnn#2{#3}{#4}
  \group_end:
  \group_begin:
  \calc_post_scan:N
}
\def_new:Npn\calc_maxmin_multiply:{
  \calc_maxmin_div_or_mul:NNnn\calc_multiply_B_by_A:}
\def_new:Npn\calc_maxmin_divide:  {
  \calc_maxmin_div_or_mul:NNnn\calc_divide_B_by_A:}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_error:N}
% The error message.
%    \begin{macrocode}
\def_new:Npn\calc_error:N#1{
  \PackageError{calc}
  {`\token_to_string:N#1'~ invalid~ at~ this~ point}
  {I~ expected~ to~ see~ one~ of:~ +~ -~ *~ /~ )}
}
%    \end{macrocode}
% \end{macro}
%
% \subsection{Higher level commands}
%
% The various operations allowed.
%
% \begin{macro}{\calc_maxof:nn}
% \begin{macro}{\calc_minof:nn}
% \begin{macro}{\maxof}
% \begin{macro}{\minof}
% Max and min operations
%    \begin{macrocode}
\def_long_new:Npn \calc_maxof:nn#1#2{
  \calc_maxmin_operation:Nnn > \exp_not:n{{#1}{#2}}
}
\def_long_new:Npn \calc_minof:nn#1#2{
  \calc_maxmin_operation:Nnn < \exp_not:n{{#1}{#2}}
}
\let_new:NN \maxof \calc_maxof:nn
\let_new:NN \minof \calc_minof:nn
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_widthof:n}
% \begin{macro}{\calc_heightof:n}
% \begin{macro}{\calc_depthof:n}
% \begin{macro}{\calc_totalheightof:n}
% \begin{macro}{\widthof}
% \begin{macro}{\heightof}
% \begin{macro}{\depthof}
% \begin{macro}{\totalheightof}
% Text dimension commands.
%    \begin{macrocode}
\def_long_new:Npn \calc_widthof:n#1{
  \calc_textsize:Nn \exp_not:N\widthof\exp_not:n{{#1}}
}
\def_long_new:Npn \calc_heightof:n#1{
  \calc_textsize:Nn \exp_not:N\heightof\exp_not:n{{#1}}
}
\def_long_new:Npn \calc_depthof:n#1{
  \calc_textsize:Nn \exp_not:N\depthof\exp_not:n{{#1}}
}
\def_long_new:Npn \calc_totalheightof:n#1{
  \calc_textsize:Nn \exp_not:N\totalheightof\exp_not:n{{#1}}
}
\let:NN \depthof\calc_depthof:n
\let:NN \widthof\calc_widthof:n
\let:NN \heightof\calc_heightof:n
\let:NN \totalheightof\calc_totalheightof:n
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\calc_ratio:nn}
% \begin{macro}{\calc_real:n}
% \begin{macro}{\ratio}
% \begin{macro}{\real}
% Ratio and real.
%    \begin{macrocode}
\def_long_new:Npn \calc_ratio:nn#1#2{
  \calc_ratio_multiply:nn\exp_not:n{{#1}{#2}}}
\let_new:NN \calc_real:n \calc_real_evaluate:nn
%    \end{macrocode}
% We can implement real and ratio without actually using these
% names. We'll see.
%    \begin{macrocode}
\let_new:NN \ratio\calc_ratio:nn
\let_new:NN \real\calc_real:n
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
%
%    \begin{macrocode}
%</initex|package>
%<*showmemory>
\showMemUsage
%</showmemory>
%    \end{macrocode}
%
% \endinput
%
%  $Log$
%  Revision 1.2  2006/01/27 23:11:47  morten
%  Fixed bug in \calc_pre_scan:N and avoid using \advance in order to
%  catch overflows.
%
%  Revision 1.1  2006/01/27 07:51:13  morten
%  Initial version of a calc module
%