Feature request: visual representation of non-printing characters

[engelhro]

Background

I've recently worked a little bit with Notepad++ and came to really appreciate its display of "non printing characters".

See the first screenshot for an example:

It shows a few Unicode non-printing characters represented by certain symbols, for example for codepoints like "zero width space", "en space", "em space", "non breaking space" and "thin space".

Feature request

That's exactly what I have in mind for Notepad3 and would like to see supported there as well.

I know that Notepad3 already shows certain symbols for characters in the, what I've learned, C0 and C1 control codes range (see second screenshot below), but that's not sufficient.

So my request is simply to extend that list… :smiley:

Details on characters that should be supported

• The Notepad++ help has a list of supported characters and their abbreviations, in the Table of Non-Printing Characters.
• And here is (based on an older Notepad++ feature request) a slightly more complete list of relevant codepoints (though Notepad++ supports only most of them, not all).

Ideas for implementation

• Display of the non-printing characters should of course be optional (the characters are there for a reason and should by default be displayed as intended, but sometimes you want to "see" and "debug" them). Thus a new option would be required in the "View menu" (I'd suggest something independent of the existing "Show Blanks" and "Show Line Endings" options).
• In case of a realization of my request one topic for discussion would be the display of line breaks (see also remarks section below), as the usage of a simple ⏎ (current solution) conflicts with a detailed CR LF (at least for Windows) representation. My idea here would be to toggle the display of line breaks dependent of the new option mentioned before (in a "simple" vs. "extended" display fashion).

Remark

As a side effect, we could have a better distinction in Notepad3 between Unix and Windows line endings:

• Notepad++ shows two different symbols for line feeds and carriage returns, so one can easily see whether a file has Unix or Windows line ending convention (or if a file contains even mixed endings!).
• Notepad3 on the other hand only shows one symbol (⏎) in either case (if the option to show line endings is enabled of course). It recognizes and reports constellations like mixed ("inconsistent") line breaks but does not make them visually discernible.