[texhax] detect characters in strings

[Philip Taylor (Webmaster, Ret'd)]

Maybe Brandon can pick something useful out of this :

\documentclass {minimal}

\def \head #1e#2\relax {#1}
\def \mantissa #1{\head #1e\relax}

\begin {document}
     \mantissa {0.00346}\par
     \mantissa {3.46e-03}\par
\end {document}


Uwe Lueck wrote:

> Somewhere earlier I wrote that the macros from substr.sty are not expandable. This really means that they break in an \edef as well as in a \typeout, sorry. And BTW, a pair of braces seems to be missing with the first \typeout ... and what are you doing with #1 in \SciToFP? Please tell what you expect \SciToFP to do ...