If `-` is not first or last in a character classes, it matches a range based on
the character code. This applies to special characters as well as to
alphanumeric characters.
- Highlight `=` and `|` as keywords (like `->` and `:`)
- Highlight custom operators (I guess they aren't really custom as of Elm 0.19
but there are still a bunch "built in").
This commit allows using the <semicolon> expansion in commands, instead
of `\;`.
It makes commands look more elegant, and prevents new-comers from
falling into the trap of using <a-;> without escaping the semicolon.
this will only highlight elm 0.19 (latest) properly
very close to how https://ellie-app.com/ highlights
- anything that starts with an upper case letter is a type
- anything that starts with a lower case letter is a function
- function declaration is just a function at the start of a line
note: the default color scheme looks too colorful
