\documentclass[load-preamble+]{cnltx-doc}

\usepackage{spbmark,siunitx}
\usepackage[noto]{newtxmath}
\setcnltx
  {
    package           = spbmark,
    title             = the spbmark package,
    version           = v1.1J,
    date              = 2021/11/10,
    authors           = Qu Yi,
    info              = Customize superscript and subscript,
    email             = q1jx@foxmail.com,
    url               = https://github.com/texl3/spbmark,
    abstract          =
      {
        \pkg*{spbmark} provides three commands \cs{super}, \cs{sub} and \cs{supersub} to improve the layout of superscript and subscript which can be adjusted the relative position and format, and can be used in text and math mode.
      },
    color-scheme      = blue,
    title-format      = \huge\bfseries\scshape,
    add-frame-options = {innerleftmargin = 2em},
    listings-options  = {numbers = none},
    pre-output        = {\parindent = 0em}
  }

\makeatletter
\newcommand{\splitmeta}[2]{\meta{#1}\texttt{,}\meta{#2}}
\newcommand{\newsplitarg}[4][\splitmeta]
  {
    \newcommand{#2}[2]
      {\code{\textcolor{argument}{#3\textnormal{#1{##1}{##2}}#4}}}
  }
\newcommand{\kvsplit}[3]{\item\code{\option{#1}\cnltx@isvalue\splitmarg{#2}{#3}}}
\newsplitarg{\splitoarg}{[}{]}
\newsplitarg{\splitmarg}{\{}{\}}
\newsplitarg{\splitdarg}{(}{)}
\makeatother

\begin{document}

\section{Macro package options}
\label{sec:macro package options}
The following macro package options will redefine the scripts commands of the \LaTeX{} kernel. If you do not specify the values of boolean options, they default to \code{true}.
\begin{options}
  \keybool{text}\Default{false}
  \cs{textsuperscript} and \cs{textsubscript} are equivalent to the \cs{super} and \cs{sub} commands.
  \keybool{math}\Default{false}
  \cs{sp} and \cs{sb} are equivalent to the \cs{super} and \cs{sub} commands.
  \keybool{foot}\Default{false}
  The format of the footnote mark match the superscript offsets and format of the \cs{spbset} global setting.
  \opt{both}\Default!
  The values of \option{text} and \option{math} two options are \code{true} at the same time.
  \opt{all}\Default!
  The values of \option{text}, \option{math} and \option{foot} three options are \code{true} at the same time.
  \begin{example}[code-only]
  \usepackage[both]{spbmark}
  \usepackage[text,foot = true]{spbmark}
  \end{example}
\end{options}

\section{User commands}
There are currently three commands to set superscript and subscript. Their format can be set temporarily using the optional parameters of the command, or set globally using a key-value list, see section \ref{sec:global control interface}.
\begin{commands}
  \command{super}[\sarg\oarg{vshift}\splitoarg{height}{depth}\darg{code}\marg{content}\oarg{hshift}]
  This is a superscript output command. If \meta{vshift} or \meta{hshift} is a positive value, the superscript moves up or to the right, if it's negative, the superscript moves down or to the left.
  \command{sub}[\sarg\oarg{vshift}\splitoarg{height}{depth}\darg{code}\marg{content}\oarg{hshift}]
  This is a subscript output command. If \meta{vshift} or \meta{hshift} is a positive value, the subscript moves down or to the right, if it's negative, the subscript moves up or to the left.
  \command{supersub}[\sarg\oarg{vsep}\darg{align}\marg{sup cont}\marg{sub cont}\oarg{hshift}\splitdarg{sup code}{sub code}]
  This is a command that outputs both superscript and subscript at the same time. You can also use the shorter command \cs{spb} instead of it. The \meta{vsep} represents the vertical spacing between superscript and subscript, same as option \option{supersubsep}. The parameters of \meta{align} are the same as the \option{supersubalign}.
\end{commands}

These commands can match the corresponding pattern depending on whether they are currently in text mode or mathematical mode, or they can use an asterisk variant to force the mathematical pattern. 

The optional parameter \splitmeta{height}{depth} generally does not need to be used. The \meta{height} and \meta{depth} are separated by commas. Only the front part indicates the \meta{height} of the superscript or subscript, and only the back part indicates the \meta{depth}.

The \meta{code} is used to format superscript and subscript, and can insert commands such as fonts or colors. The last command in the code can take an argument, which is either a superscript or a subscript.

If you need to use the original definitions of \cs{textsuperscript}, \cs{textsubscript}, \cs{sp} and \cs{sb} after using the \option{text} or \option{math} option, then you can use the following commands:
\begin{commands}
  \command{spb@textsuperscript@save}[\marg{content}]
  Save the original definition of the \cs{textsuperscript} command, output superscript in the text.
  \command{spb@textsubscript@save}[\marg{content}]
  Save the original definition of the \cs{textsubscript} command, output subscript in the text.
  \command{spb@sp@save}[\marg{content}]
  Save the original definition of the \cs{sp} command, output superscript in the math mode.
  \command{spb@sb@save}[\marg{content}]
  Save the original definition of the \cs{sb} command, output subscript in the math mode.
\end{commands}

\section{Global control interface}
\label{sec:global control interface}
\begin{commands}
  \command{spbset}[\marg{key-value list}]
  \pkg*{spbmark} uses the \cs{spbset} command to control the global default format of superscript and subscript. The values ​​set by it will be overwritten by the optional parameters of the superscript and other commands.
\end{commands}

The following list of keys control the format both of superscript or subscript. They are equivalent to the optional parameters of the \cs{super} or \cs{sub} commands.
\begin{options}
  \keyval{super-vshift}{fixed length}\Default{0pt}
  Extra vertical shift of the superscript.
  \keyval{super-hshift}{fixed length}\Default{0pt}
  Extra horizontal shift of the superscript.
  \keyval{sub-vshift}{fixed length}\Default{0pt}
  Extra vertical shift of the subscript.
  \keyval{sub-hshift}{fixed length}\Default{0pt}
  Extra horizontal shift of the subscript.
  \opt{nohshift}\Default!
  Cancel the horizontal offset of superscript and subscript at the same time.
  \opt{novshift}\Default!
  Cancel the vertical offset of superscript and subscript at the same time.
  \keyval{super-format}{format code}\Default
  Control the format of superscript, the last command in the code can take an argument, which is a superscript.
  \keyval{sub-format}{format code}\Default
  Control the format of subscript, the last command in the code can take an argument, which is a subscript.
\end{options}

The following list of keys control the format of superscript and subscript. They are equivalent to the optional parameters of the \cs{supersub} command.
\begin{options}
  \keyval{supersub-hshift}{fixed length}\Default{0pt}
  Extra vertical shift of the superscript and the subscript.
  \kvsplit{supersub-format}{super code}{sub code}\Default{0pt}
  Control the format of superscript or subscript. The first part is in superscript format, and the latter part is in subscript format. The two are separated by commas, or only the first part exists.
  \keyval{supersubsep}{fixed length}\Default{0.3ex}
  The distance between superscript and subscript, its default value is \code{0.3ex}.
  \keychoice{supersubalign}{l,c,r}\Default{l}
  The alignment of superscript and subscript, which contains \code{l}, \code{c}, and \code{r} parameters respectively for left, center, and right alignment.
\end{options}

\section{Examples of use}
Here is a list of the three commands, please pay attention to the delimiter and usage of optional parameters. Note when the horizontal offset is negative, the starting point is at the right end of the mark.
\begin{example}
\spbset{supersub-format = {\ttfamily,\color{blue}}}
A\super[0.2ex](\textcolor{red}){exam}[0.2em]B \\
$A\sub(\mathsf){exam}B$ \\
A\supersub[0.3ex](c){examsuper}{sub}B \\
A\super[5pt]{c}[-1.5pt]B\sub[5pt]{d}[-1pt]AB
\end{example}

It can also be used with the \pkg*{siunitx} package to output superscript and subscript in the unit:
\begin{example}
\unit[mode = math]{kg.m/s\super*[-1pt]{2}} \\
\qty[mode = text]{30}{A\supersub{b}{c}[1pt](\color{red})} \\
\spbset{sub-hshift = 2pt}\unit[mode = text]{A\sub{b}}
\end{example}

\pkg*{spbmark} also patches the footer markers for standard document class and \cls*{KOMA-Script}. You can format the footer markers by redefining the \cs{fnmarkfont} command. Note that extra horizontal shift does not work with footnote markers.

\section{Known issues}
At present, the vertical and horizontal offsets are effective for the unit commands in the \pkg*{siunitx} macro package. However, due to the special mechanism that the decimal point is not recognized correctly because it's converted to a space in the \cs*{unit} command, it's recommended to use \code{pt} as the unit of offset.

\nocite{*}

\end{document}