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All top-level def forms should have consistent font-lock #578
Description
Some thoughts on syntax highlighting.
(def foo 42) ; font-lock-variable-name-face
(defn bar [x] x) ; font-lock-function-name-face
I think variable-name-face should be used for foo in (let [foo 42] ...), but not for foo in (def foo 42). Top-level definitions should use the same face, whether its a function or a 'variable'. It seems more logical, since if I want to make both "foo" and "bar" use the same bold and highly visible face (since both are top-level defs), then e.g. in my c code I get local variables and function arguments highlighted with the same face.
I guess the correct hierarchy would be: top-level-definition-face -> (function-face, var-face[1]). It would be nice to have a separate space for def-like keywords as well (so a user could highlight "defn", but not "do" or "let").
[1]: technically defn also creates a var; what's the best short name for a top-level definition that is not a function? Do we actually need/want this distinction at all? I don't really see how it's useful.
Activity
bbatsov commentedon Nov 13, 2020
I've tried to align the font-locking in
clojure-modeto that inlisp-modeandelisp-mode. Obviously there are some differences between a Lisp-1 and Lisp-2, but I think we won't gain much by changing the fock-locking for definitions. None of the existing Lisp modes for Emacs try to font-lock locals, so I didn't bother to so as well.j-cr commentedon Nov 13, 2020
I don't care that much about highlighting locals too. My main point's that logically all top-level definitions are kinda on the same level of "importance", so should be highlighted similarly, whether it's defined with a
defordefn(or other def-like forms).But setting
font-lock-variable-name-face(currently used for(def x ...)definitions) to be the same as function-name face (i.e. bold and bright) also makes local variables in other languages bold and bright (local variables in other lang modes use the same face:font-lock-variable-name-face).Anyways, feel free to close as you see fit, as it's not a feature request per se but more of "what's your thoughts on this" type ticket; or maybe leave open to gather more opinions.
yuhan0 commentedon Nov 27, 2020
For what it's worth, I do exactly this special highlighting of all
def...forms on my local fork of clojure-mode, and I find it helps greatly with visual parsing of code.This was done with a custom
clojure-definition-facethat is applied equally to all def.. forms, without distinguishing between def / deftype / defn.I do realise it's not for everyone and doesn't align well with other Emacs modes as pointed out above, just posting since there's interest.
The font lock keyword:
jpe90 commentedon Jan 4, 2022
@yuhan0 Would it be possible to share your local fork? That special highlighting looks great, but it looks you're using definitions of
clojure--whitespace-regexpandclojure--type-or-metadata-regexpthat aren't shown if I understand correctly