You can use `makeFields` from the `lens` package to get something like:
someData ^. field1 . field2
along with modifiers:
someData & field1 . field2 %~ (* 2)
and setters:
someData & field1 . field2 .~ 42
where `field1` is polymorphic and can apply to many different data types
Matt Parsons
On Mon, May 14, 2018 at 6:41 PM, Dennis Raddle
In my current application, I'm really missing the ability from OO to do things like
someData.field1.field2 = "foo"
What's do I mean?
- field selectors are scoped so that names don't clash with each other or global names
- this way of selecting data can be used both for reading it, and for updating specific fields of some data deep in a data hierarchy (In Haskell, if using immutable data, this would requiring doing a data update on every level).
Any attempt to do this in Haskell, for me anyway, results in an explosion of names and a lot of boilerplate code and a resulting heavy syntax.
Is there a way of obtaining OO-like concise syntax, perhaps with Template Haskell?
Dennis
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