Defining Polymorphic objects in algorithm2e

Question

I'm currently writing my masters thesis and I'm using algorithm2e to write pseudocode. I regularly use SetKwData to display data types. However I would slighty like to change how this is displayed when using arguments.

If I for example would like to display a key value map data type that is polymorphic in both the key, and data I would write something like this

\SetKwData{DFoo}{Foo}
\SetKwData{DBar}{Bar}
\SetKwData{DMap}{Map}

\Dmap{\DFoo, DBar}

Then the compiled document would look something like

Map(Foo, Bar)

In my opinion this looks too much like a function call. I would like to change the parenthesis to something like Map<Foo, Bar>.

Answer 1

In the example below, based on how \SetKwData{Kw}{the text} is defined in algorithm2e.sty, a generalized macro \SetKwMetaData{Kw}{the text}{left delimiter}{right delimiter} is provided, which allows you to specify the delimiters. These delimiters were hard coded to be ( and ) in \SetKwData.

\documentclass{article}
\usepackage{algorithm2e}

\makeatletter
% \SetKwMetaData{Kw}{the text}{left delimiter}{right delimiter}
\newcommand{\SetKwMetaData}[4]{%
  \algocf@newcommand{@#1}[1]{\DataSty{#2#3}\ArgSty{##1}\DataSty{#4}}%
  \algocf@newcommand{#1}{%
    \@ifnextchar\bgroup{\csname @#1\endcsname}{\DataSty{#2}\xspace}}%
  }%
\makeatother

\SetKwData{DFoo}{Foo}
\SetKwData{DBar}{Bar}
\SetKwMetaData{DMap}{Map}{$\langle$}{$\rangle$}

\begin{document}
\begin{algorithm}
  \DFoo{a}\\
  \DMap{\DFoo, \DBar}
\end{algorithm}
\end{document}