Add class-name highlighting for Eiffel

[Conaclos]

Hi!

The creation of external theme, in particular a themes, in particular the EiffelStudio IDE theme, the Eiffel language definition must enable highlighting of the class-names.

I based the regex on the unanimously used Eiffel convention for class naming (i.e. class-names are always all upper-case characters).
The only known issue is that the formal generics are considered as class names...

Thanks.

[LeaVerou]

How big of an issue is that? What are formal generics? Is there anything to distinguish them on the syntax level?

(also, thanks!)

[Conaclos]

Formal generic parameters and class-names

Eiffel Standard (ECMA 367) 8.12:

The genericity mechanism, still based on classes, gives us a new level of flexibility through type parameterization. You may for example define a class as LIST [G], yielding not just one type but many: LIST [INTEGER], LIST [AIRPLANE] and so on, parameterized by G.

The only way to know if the identifier is a class-name or a formal generic parameter is to know the class declaration.
e.g.

deferred class
    A [G]

feature
    items: G
        deferred  end

end

The declaration class A [G] enables to say that G is a formal generic parameter. All occurrences of G in the class denotes this generic.

[Conaclos]

@LeaVerou

Is it really an issue?

Using the same CSS class for class-names and formal generic parameter names is not really a problem. The notion are related...

[Conaclos]

@Golmote Hi!

A new commit from @carlfriess is now integrated (See #827).

Eiffel users which use Prism for Eiffel highlighting gave me a positive feedback about this PR.
For example http://eiffel-guide.com/ uses a modified version of Prism in order to benefit of these changes.

[Golmote]

Sorry for the long time waiting. Thank you for contributing!