Improve PlaintextSyntaxHighlighter

[guanglinn]

Make PlaintextSyntaxHighlighter have versatile languages syntax highlight function based on configuration files (JSON), and add several popular language (C, C++, Java, Python) syntax highlight. Which language to be highlighted depends on the plain text file extension.

[guanglinn]

Screenshot ↓

[gsantner]

Thank you! Is that json format of some other tool / something generic where other languages can be fetched from?
Or where did you get those from?

[guanglinn]

I referred to these projects for Markor's current JSON syntax highlighting configuration files.

Their syntax highlighting definitions are advanced and sophisticated, I don't know how to directly use these files, so I just reused some basic regex from these files, such as keywords, variable, string, number, function and comment ...

By the way, I found many text editors use TextMate grammars to highlight. Maybe we can use TextMate grammars for Markor, and if use it, we can directly use these syntax highlighting configuration files.

1. PrismJS

PrismJS syntax highlighting configuration files

2. sora-editor

sora-editor

Using TextMate grammars.

3. Xed-Editor

Xed-Editor syntax highlighting configuration files

Using TextMate grammars.

4. Visual Studio Code

Syntax Highlight Guide

Using TextMate grammars.

[gsantner]

If you feel any is somewhat similar to whats feasible for Markor, feel free to rearrange the json/definition structure.

I asked also because saw the keyword list and what came to my mind were Geany filedefs (https://github.com/geany/geany/blob/master/data/filedefs/filetypes.java)

[gsantner]

Thanks, I did further improvements and fixes (i.e. it was crashing for files that are not one of those py/java/..).

Good enough for getting it in use as first. Good also that its fully app internal for now (no external loading), this allows to further improve (i.e. change the language definition syntax).