6 ms·
For example: I personally prefer the standard form here, as (to me) it reads a bit more like English: over (location.x) (+ 10) $ player1 "over location's x, a
by ozataman 13y ago
For example: I personally prefer the standard form here, as (to me) it reads a bit more like English:
over (location.x) (+ 10) $ player1
"over location's x, add 10"
- tel 13y agoThere's also the player1 & location.x .~ (+10) format which has a nice scansion.
- drostie 13y agoIt seems like there should be a way to define player1 as its own (root) lens so that one is simply writing player1.location.x .~ (+10), or so. Are we simply not doing this because it makes reading the data structure rather difficult?
- tel 13y agoThat can kind of be done using `Context`s, but those are really just implementation details and should rarely be used. Broadly, you wouldn't want to do that because it implies mutation. There's not much value in `player1.location.x %~ (+10)` because it can't modify player1... just return a modified (player1'new). Of course, stateful mutation is just a monadic effect, so you can wrap it up into a State monad, which Lens already has shortcuts for do location.x += 10 location.y += 10 which has type like `MonadState ThingWithLocation m => m ()` and we can then apply it to whatever `player` we want as a pure function.