Highlighting Filepath Strings: Prevent Escapes

[tajmone]

Hugo highlighted code: false positive escapes and interpolations in filepath strings.

• Temporary CSS workaround:
  • Create .noescapes class to color escapes and interpolations like strings.
  • Add noescapes role to all code blocks where the problem occurs.
• Fix the Hugo syntax for Highlight.

The Problem

Currently, the HL Hugo syntax looks for escapes and interpolations inside all strings, which is a problem when dealing with filepath strings containing Windows paths, where the backslash dir separator can lead to false positive escape sequences and special characters (interpolations in HL syntax).

An example of this can be seen in §12.1 (commit 37d44a0), before the CSS patch (click here for current view):

resource "GAMERES1"
{
    "c:\hugo\graphics\logo.jpg"
    "h:\data\scenic panorama.jpg"
    "h:\data\background.jpg"       <- \b highlighted as "bold end"
    "c:\music\intro_theme.s3m"     <- \i highlighted as "italic end"
    "c:\music\theme2.xm"
    "c:\sounds\sample1.wav"
    "c:\sounds\sample2.wav"
}

While the syntax was already fixed to prevent escapes and interpolations inside compiler directive strings for #include and #link, fixing the above problem is turning out trickier than expected.

I need to find a way to distinguish between text- and path-strings, by introducing some state tracking variable after keywords like resource, image and all other keywords which are followed by a filepath string.

So far, all attempts in this direction failed (i.e. they didn't work for multiple strings, like in the above example).

Real tests for this can be found on the Hugo dev branch of the Highlight Test Suite on GitLab:

• syntax_test_filepaths-include.hug
• syntax_test_filepaths-resources.hug

A Quick Workaround

As a temporary solution, I can create a .noescape CSS rule that colors escape sequences and interpolations with the same color as strings, effectively hiding the problem to the eye.