Double 'evaluate' in one PGF's \foreach

Question

percusse may know if I can do the following with \foreach:

\begin{document}
\foreach [
  evaluate=\x as \z using \x*10,
  evaluate=\x as \p using \x mm*3
] \x in {1,...,5}{
  \endgraf
  \hskip\p pt\relax
  \textcolor{red!\z!blue}{\x}%
}
\end{document}

Aside

\foreach should help newbie with an intelligent message in a case like the following:

\foreach [
  remember=\x % as \lastx (initially A) % n00b forgot the rest.
] \x in {B,C,D,E,F,G,H}{%
  $\overrightarrow{\lastx\x}$,
}

Answer 1

The evaluate keyword invokes the PGF math engine, which always saves its results in units of pt, but without the pt string. So if you use

\hskip\p pt\relax

(adding the pt after the \p), you get the desired result:

\documentclass[10pt]{article}
\usepackage{tikz}
\begin{document}
\foreach [
  evaluate=\x as \z using \x*20,
  evaluate=\x as \p using \x mm*3
] \x in {1,...,5}{
  \endgraf
  \hskip\p pt\relax
  \textcolor{red!\z!blue}{\x}%
}
\end{document}