Allow search by type signatures

[renatoathaydes]

Hi, I would like to submit a feature request: to allow Ceylon programmers to search for modules/functions by type signature (in addition to normal "search by name").

This would be similar to Haskell's Hoogle

I can imagine that it would be really useful to search by type in Ceylon.

** Example 1: **
Find all functions that take a File and gets a sequence of Strings (probably a function that reads the file and returns all lines in it?):

String[](File)

** Example 2: **
Find a function that takes iterables of something (a generic type) and returns an Iterable of something elses (maybe looking for concatenate that allows transforming the items):

<From, To> {To*}((To(From), {From*}*)

This obviously suits Haskell, and in my opinion, Ceylon too.

[FroMage]

That's a good idea, but it sounds very hard to implement, especially if we can search for subtypes.