Arrows composition is not completely associative about slothql HOT 3 CLOSED

val m1 = Functor.map(sel3 ∘ (sel2 ∘ sel1)).to[DBArrow]
val m2 = Functor.map(sel3).to[DBArrow] ∘ Functor.map(sel2 ∘ sel1).to[DBArrow]
m1 == m2 // true

from slothql.

At Arrow's level composition should be associative: sel3 ∘ (sel2 ∘ sel1) ~ (sel3 ∘ sel2) ∘ sel1, like paths. At F, F should respect paths F(sel1 ∘ sel2) ~ F(sel1) ∘ F(sel2), sel1 ∘ sel2 is a single arrow for F.

from slothql.

The domain category of the functor does not include arrow sel2, nor ? ∘ sel2, only sel2 ∘ ?. Since sel3 ∘ sel2 is not in the domain of the functor, compilation failure is the expected behavior.

from slothql.