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by thelambentonion 3455 days ago
Expanding on this a bit, the concept that Hoogle embodies is extremely powerful and I wish it were more widely available in other languages.

In Haskell's case, due to the particulars of the type system, something like Hoogle is _relatively_ straightforward. More importantly, the same system that makes Hoogle possible also enables safe code exploration and reuse.

Eschewing simpler examples for something a little more production-y, I dug up something that came about after a conversation a few weeks back:

    ( MonadIO m
    , PersistEntity val
    , PersistEntityBackend val ~ SqlBackend
    ) => m [Entity val]
Line by line, the signature (roughly) encodes the following [1]:

1) The context `m` must provide the ability to perform I/O

2) `val` must have some representation understandable by the Persistent ORM [2]

3) `val` must have some backend within the Persistent ORM [2] that satisfies the `SqlBackend` constraint

4) The function provides a list of `Entity val`, where `Entity` is a Persistent-specific implementation detail, within some context `m`.

IMO, this is incredibly useful for searchability because it encodes everything I said above (and more precisely, at that!). Further, these terms can be pulled apart, rearranged, and composed to form more, or less, specific concepts in a query.

This is _also_ useful for code reuse, as seeing these specifications can help identify points of repetition, and encourage higher levels of abstraction.

Apologies if this got a little away from the heart of the discussion and turned into a bit of a brain-dump towards the end :)

[1] I'm not using the most precise wording here, mostly due to my own incomplete understanding of things

[2] Persistent isn't exactly an ORM, but it's the closest analogy I can think of given how comprehensive it is
1 comments
Apsion 3455 days ago
This is great - checking out Hoogle now.

I love abstractions, although at times they become a barrier to edge use cases. I guess the art is determining how much to abstract.

Perhaps I am oversimplifying the way I was imagining the search. In my mind it could simply be a pattern match (including special characters) and return the results. Then the zoom in/out capability would allow you to determine if the result is applicable.

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