LaTeX writer: use "\phantom{\ }" to escape spaces in texttt

This approach seems more robust, and solve the issue of normal escaped spaces not working after a forced line break inside texttt command.

src/Text/Pandoc/Writers/LaTeX.hs

@@ -832,7 +832,7 @@ inlineToLaTeX (Code (_,classes,_) str) = do
          rawCode = liftM (text . (\s -> "\\texttt{" ++ escapeSpaces s ++ "}"))
                           $ stringToLaTeX CodeString str
            where
-             escapeSpaces =  concatMap (\c -> if c == ' ' then "\\ " else [c])
+             escapeSpaces =  concatMap (\c -> if c == ' ' then "\\phantom{\\ }" else [c])
 inlineToLaTeX (Quoted qt lst) = do
   contents <- inlineListToLaTeX lst
   csquotes <- liftM stCsquotes get

tests/scholdoc.latex

@@ -4,9 +4,10 @@ support}\label{scholarlymarkdown-math-support}
 \subsection{Math as (fenced) code
 blocks}\label{math-as-fenced-code-blocks}
 
-This is a line of text with a \texttt{simple\ code\ block} in it.
+This is a line of text with a
+\texttt{simple\phantom{\ }code\phantom{\ }block} in it.
 
-\texttt{`this\ should\ be\ just\ a\ `normal`\ inline\ code\ block\ surrounded\ by\ literal\ backticks`}
+\texttt{`this\phantom{\ }should\phantom{\ }be\phantom{\ }just\phantom{\ }a\phantom{\ }`normal`\phantom{\ }inline\phantom{\ }code\phantom{\ }block\phantom{\ }surrounded\phantom{\ }by\phantom{\ }literal\phantom{\ }backticks`}
 
 This is another line of text. Here should be some math:
 $\mathbf{F = ma}<2\mathbf{ma}$. There should be some displaymath
@@ -131,8 +132,8 @@ Here's a list with both inline and display math environments:
 \item
   Item 1 is a famous item
 \item
-  Item 2 with a \texttt{code\ block} and $\mathsf{\text{inline math}}$
-  with equation $\mathbf{y=Ax}$
+  Item 2 with a \texttt{code\phantom{\ }block} and
+  $\mathsf{\text{inline math}}$ with equation $\mathbf{y=Ax}$
 \item
   Item 3
 
@@ -265,9 +266,9 @@ Here are some algorithms using various methods. The ``most canonical
 one'' is currently just using a line-block:
 
 \begin{scholmdAlgorithm}
-\texttt{\ 1.}~\textbf{Inputs}:~variables~$A, b$\\\texttt{\ 2.}~\textbf{Output}:~$\phi$~~~~~~~~~~~~~~~~\texttt{//this\ is\ a\ comment}
+\texttt{\phantom{\ }1.}~\textbf{Inputs}:~variables~$A, b$\\\texttt{\phantom{\ }2.}~\textbf{Output}:~$\phi$~~~~~~~~~~~~~~~~\texttt{//this\phantom{\ }is\phantom{\ }a\phantom{\ }comment}
 
-\texttt{\ 3.}~Choose~an~initial~guess~$\phi$~to~the~solution\\\texttt{\ 4.}~~\textbf{repeat}~until~convergence\\\texttt{\ 5.}~~~~\textbf{for}~$i$~\textbf{from}~1~\textbf{until}~$n$~\textbf{do}\\\texttt{\ 6.}~~~~~~~~$\sigma \leftarrow 0$\\\texttt{\ 7.}~~~~~~~~\textbf{for}~$j$~\textbf{from}~1~\textbf{until}~$n$~\textbf{do}\\\texttt{\ 8.}~~~~~~~~~~~~\textbf{if}~$j \ne i$~\textbf{then}\\\texttt{\ 9.}~~~~~~~~~~~~~~~$\sigma \leftarrow \sigma + a_{ij} \phi_j$\\\texttt{10.}~~~~~~~~~~~~\textbf{end~if}\\\texttt{11.}~~~~~~~~\textbf{end}~($j$-loop)\\\texttt{12.}~~~~~~~~$\phi_i \leftarrow \frac 1 {a_{ii}} (b_i - \sigma)$\\\texttt{13.}~~~~\textbf{end}~($i$-loop)\\\texttt{14.}~~~~check~if~convergence~is~reached\\\texttt{15.}~\textbf{end}~(repeat)
+\texttt{\phantom{\ }3.}~Choose~an~initial~guess~$\phi$~to~the~solution\\\texttt{\phantom{\ }4.}~~\textbf{repeat}~until~convergence\\\texttt{\phantom{\ }5.}~~~~\textbf{for}~$i$~\textbf{from}~1~\textbf{until}~$n$~\textbf{do}\\\texttt{\phantom{\ }6.}~~~~~~~~$\sigma \leftarrow 0$\\\texttt{\phantom{\ }7.}~~~~~~~~\textbf{for}~$j$~\textbf{from}~1~\textbf{until}~$n$~\textbf{do}\\\texttt{\phantom{\ }8.}~~~~~~~~~~~~\textbf{if}~$j \ne i$~\textbf{then}\\\texttt{\phantom{\ }9.}~~~~~~~~~~~~~~~$\sigma \leftarrow \sigma + a_{ij} \phi_j$\\\texttt{10.}~~~~~~~~~~~~\textbf{end~if}\\\texttt{11.}~~~~~~~~\textbf{end}~($j$-loop)\\\texttt{12.}~~~~~~~~$\phi_i \leftarrow \frac 1 {a_{ii}} (b_i - \sigma)$\\\texttt{13.}~~~~\textbf{end}~($i$-loop)\\\texttt{14.}~~~~check~if~convergence~is~reached\\\texttt{15.}~\textbf{end}~(repeat)
 \caption{caption for this algorithm}\label{alg:gs}
 \end{scholmdAlgorithm}
 

tests/writer.latex

@@ -740,7 +740,8 @@ These shouldn't be math:
 \begin{itemize}
 \itemsep1pt\parskip0pt\parsep0pt
 \item
-  To get the famous equation, write \texttt{\$e\ =\ mc\^{}2\$}.
+  To get the famous equation, write
+  \texttt{\$e\phantom{\ }=\phantom{\ }mc\^{}2\$}.
 \item
   \$22,000 is a \emph{lot} of money. So is \$34,000. (It worked if ``lot'' is
   emphasized.)