LaTeX instructions. Address #388.

LaTeX-instructions.md

@@ -0,0 +1,70 @@
+This page is intended for those who wish to use the Fira Code font in the LaTeX *output* files. If you wish to use Fira Code to display your LaTeX source files, then please check whether your LaTeX editor supports Fira Code or not.
+
+## Activate ligatures in `lstlisting`
+
+The [`lstfiracode`](https://www.ctan.org/pkg/lstfiracode) package defines `FiraCodeStyle` for the use with the [`listings`](https://www.ctan.org/pkg/listings) package. Here is a sample LaTeX document:
+
+    % !TeX program = XeLaTeX or LuaLaTeX
+    % !TeX encoding = UTF-8 Unicode
+    \documentclass{article}
+    \usepackage{fontspec}
+    \setmonofont{Fira Code}[
+      Ligatures=Common,      % Activate the liga feature
+      Contextuals=Alternate  % Activate the calt feature
+    ]
+    \usepackage{listings}
+    \usepackage{lstfiracode} % https://www.ctan.org/pkg/lstfiracode
+    \lstset{
+      language=C++,
+      style=FiraCodeStyle,   % Use predefined FiraCodeStyle
+      basicstyle=\ttfamily   % Use \ttfamily for source code listings
+    }
+    \begin{document}
+    \begin{lstlisting}
+    /* A simple C++ program */
+    int main() {
+        cout << "Hello World"; // prints Hello World
+        return 0;
+    }
+    \end{lstlisting}
+    \end{document}
+
+## Activate ligatures in `verbatim`
+
+The [`lstfiracode`](https://www.ctan.org/pkg/lstfiracode) package also supports the `verbatim` environment. Here is a sample LaTeX document:
+
+    % !TeX program = XeLaTeX or LuaLaTeX
+    % !TeX encoding = UTF-8 Unicode
+    \documentclass{article}
+    \usepackage{fontspec}
+    \setmonofont{Fira Code}[
+      Ligatures=Common,      % Activate the liga feature
+      Contextuals=Alternate  % Activate the calt feature
+    ]
+    \usepackage{listings}
+    \usepackage{lstfiracode} % https://www.ctan.org/pkg/lstfiracode
+    \begin{document}
+    \ActivateVerbatimLigatures
+    \begin{verbatim}
+    A<-www>>=B
+    \end{verbatim}
+    \end{document}
+
+If you do not want to load the `lstfiracode` package, here is another solution:
+
+    % !TeX program = XeLaTeX or LuaLaTeX
+    % !TeX encoding = UTF-8 Unicode
+    \documentclass{article}
+    \usepackage{fontspec}
+    \setmonofont{Fira Code}[
+      Ligatures=Common,      % Activate the liga feature
+      Contextuals=Alternate  % Activate the calt feature
+    ]
+    \makeatletter
+    \renewcommand*\verbatim@nolig@list{} % Empty the no-ligature list
+    \makeatother
+    \begin{document}
+    \begin{verbatim}
+    A<-www>>=B
+    \end{verbatim}
+    \end{document}