\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{mkessler-mathalias}[2021/09/09 Easy aliasing for math style commands]

%%%%%%

\newif\ifmkessler@mathalias@basic\mkessler@mathalias@basicfalse
\DeclareOption{basic}{\mkessler@mathalias@basictrue}

\newif\ifmkessler@mathalias@extended\mkessler@mathalias@extendedfalse
\DeclareOption{extended}{\mkessler@mathalias@extendedtrue\mkessler@mathalias@basictrue}

\DeclareOption*{\PackageWarning{mkessler-mathalias}{Unknown '\CurrentOption'}}
\ProcessOptions\relax

%Usage: \makealiasesforwith\<mathcommand>{<prefix>}{<Set of letters>}
% to declare commands of form \<prefix><Letter> as \<mathcommand>{<Letter>} for each
% of the specfied letters
% 
% E.g. \makealiasesforwith\mathcal{c}{ABC} will declare
% \cA \cB \cC \cD as \mathcal{A}, \mathcal{B}, \mathcal{C}
% This is also ensuring math context, so that
% \cA will be valid even in normal text.

\def\makealiasesforwith#1#2#3{
    \def\mkessler@aliases@makealias##1{
        \expandafter\def\csname #2##1\endcsname{\ensuremath{#1{##1}}}
    }
    \def\mkessler@aliases@recurse##1{
        \ifx##1\mkessler@dummy\else
        \mkessler@aliases@makealias{##1}\expandafter\mkessler@aliases@recurse\fi
    }
    \mkessler@aliases@recurse #3\mkessler@dummy
}

\def\mkessler@mathalias@all{ABCDEFGHIJKLMNOPQRSTUVWXYZ}

\ifmkessler@mathalias@basic
    \RequirePackage{amsfonts}
    \makealiasesforwith\mathbb{}{CFKNQRZ}
\fi

\ifmkessler@mathalias@extended
    \expandafter\makealiasesforwith\expandafter\mathcal\expandafter{\expandafter c\expandafter}\expandafter{\mkessler@mathalias@all}
    \expandafter\makealiasesforwith\expandafter\mathfrak\expandafter{\expandafter f\expandafter}\expandafter{\mkessler@mathalias@all}
\fi