No judgement if that is good or bad or at all. Just a reminder that it ain't monospace any longer.
> Your code is still monospaced in all the ways that matter.
Just it ain't monospace any longer. (reminder)
In monospace one letter/symbol (printable character) has constant width.
The ligature is one letter/symbol. so while the stylistic decision retains the monospace style of the replaced symbols, the ligature itself is double (or triple) sized compared with other symbols.
IIRC this is commonly called "monospaced ligatures" ref https://github.com/tonsky/FiraCode/issues/712
E.g. a compacting ligature for "www" seems to be welcome in some typefaces for coding. But again, only to stress the reminder: It ain't monospace any longer.
We do still may prefer for the typesetting pleasantry that it still is styled as monospace (or fixed width). but those ligatures aren't fixed width any longer as with the letter A, that's all.
This is the difference between what it looks like (two or three glyphs) and what it is (a single glyph). So we break monospace to keep it appearing fixed-width even with the ligatures.
Would be interesting if there is more typesetting theory about the width of ligatures in a monospace font.
1 ASCII byte, 1 cell. That way ligatures don't change the width of the original text. If a line used to require 42 columns, it still requires 42 columns. That's why we call them "monospace": each ASCII byte requires the exact same width, even when it's part of a ligature.
> a compacting ligature for "www" —
Is obviously out of scope. We're discussing monospace ligatures here, not compacting ones.