Only translate trait method when used

[Nadrieril]

Currently, whenever we translate a trait like Iterator, we translate the signature of its many dozen methods. We could instead start each trait without any methods and only translate each method when we encounter it in the code.

[sonmarcho]

I agree with this. Just a small request: it would be good to have an option to switch between the two behaviors (but this is probably what you had in mind).

[Nadrieril]

I intend this to be part of the normal crate exploration behavior, therefore if you want to include all iterator methods and bodies you can use --include core::iter::Iterator. If you want just the method signatures, you can use --include core::iter::Iterator --opaque core::iter::Iterator::*.

[sonmarcho]

I often use the current behavior to generate models for the backends: it's an easy of getting the trait declaration, method declarations and instance declarations for free. I'm perfectly fine if what you suggest becomes the new default behavior, but it would be good if we could use an option to re-activate the current behavior (should be simple right?).

[Nadrieril]

When generating models you can just --include *, no? Eventually I want the name matcher to support item kinds and to adjust the recursive meaning of patterns, in which case the flag you want will also be equivalent to --include 'trait *'.

[sonmarcho]

Following an offline discussion: the best solution so far is to have options which are actually sugar for --include of the proper pattern. This way we have a general mechanism to control which items get included or not and the implementation doesn't have to handle ad-hoc cases, while users have shortcuts which are easy to use for some common patterns.