Automatic raise of punctuating commas inside math mode

Question

How to have a switch to turn on/off the raising of punctuating commas inside the math mode so that (when the switch is true) they are typeset by \newcommand{\CommaPunct}{\mathpunct{\raisebox{0.5ex}{,}}} as suggested by this answer?

\documentclass{article}
\usepackage{amsmath}
\newcommand{\CommaPunct}{\mathpunct{\raisebox{0.5ex}{,}}}
\begin{document}
    \noindent
\verb|\mathpunct|: $\frac{1}{2} \CommaPunct \frac{3}{4} \CommaPunct \dfrac{1}{2} \CommaPunct \dfrac{3}{4}$\\

Here, after setting the automatic raise to true, the commas should be printed as above\\

$\frac{1}{2} , \frac{3}{4} , \dfrac{1}{2} , \dfrac{3}{4}$   

\end{document}

Answer 1

\documentclass{article}
\usepackage{amsmath,parskip}
\newcommand{\CommaPunct}{\mathpunct{\raisebox{0.5ex}{,}}}
\mathchardef\commaorig\mathcode`,
\mathcode`,="8000
{\catcode`,\active
\protected\gdef,{\ifraisedcomma\CommaPunct\else\commaorig\fi}
}
\newif\ifraisedcomma
\begin{document}
    \noindent % a strange way of adding vertical space
\verb|\mathpunct|: $\frac{1}{2} \CommaPunct \frac{3}{4} \CommaPunct \dfrac{1}{2} \CommaPunct \dfrac{3}{4}$% no!!!!\\

Here, after setting the automatic raise to true, the commas should be printed as above% never end paragraph with \\

$\frac{1}{2} , \frac{3}{4} , \dfrac{1}{2} , \dfrac{3}{4}$   


\raisedcommatrue
$\frac{1}{2} , \frac{3}{4} , \dfrac{1}{2} , \dfrac{3}{4}$   

\end{document}