`obj` position in argument order

JuliaObjects / Accessors.jl

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`obj` position in argument order #154

Open jariji opened 4 weeks ago

jariji commented 4 weeks ago

Higher-order functions like map(f, obj) usually put the data argument last. In Accessors, it's usually hof(obj, optic, val) or modify(f, obj, optic) where the data argument comes earlier, which I didn't expect. I'm interested what explains this decision?

jw3126 commented 4 weeks ago

In very early Setfield.jl commits the order was actually like you suggested. However:

I found it confusing that the order is switched in @set obj.field = val and set(@lens(_.field), obj, val)
There is one good reason to put functions first, namely do blocks. However, this advantage is lost if the first argument is an optic.
Also back in the day I missed/did not take seriously enough the viewpoint, that a lens is just a function that has a set method as well.