Why is the syntax of "." punctuation?

[ikirill]

"." is a valid constituent of qualified identifiers, e.g., Data.List.map, so shouldn't it have symbol-constituent syntax?

This has the side effect that (thing-at-point 'symbol) (which is emacs-standard) doesn't quite work correctly: when placed on a qualified identifier, it selects only the unqualified identifier or a part of the module name (e.g., map or Data or List).

Is this intentional, or a bug?

[gracjan]

"." has many functions in Haskell. Example:

forall a . a -> a
f . g
Data.List.map
Control.Category..  (note two dots at the end)

It is best to treat "." default as punctuation.