Question

For some reason the term lexer or parser comes mind. I realise these terms are often associated with compilers, but I don’t want to make any assumptions. For example, when you open .cpp file in gedit, it colors string literals, numeric values, data types, etc all different colors to make it a bit more readable. The same goes with SO and visual studio. What’s the term for what these programs are doing?

Answer 1

Syntax highlighting. From Wikipedia:

Syntax highlighting is a feature of some text editors that display
text—especially source code—in different colors and fonts according to
the category of terms. This feature eases writing in a structured
language such as a programming language or a markup language as both
structures and syntax errors are visually distinct. Highlighting does
not affect the meaning of the text itself; it’s made only for human
readers/editors.