Edward Kmett wrote:
I think in many ways the strict left to right effect evaluation order is what makes Applicative code readable.
I was going to mention that as the potential downside. However, I'd interpret my version in the same vein as ($!). That is: evaluate the argument, evaluate the function, invoke function on argument. The ($!) combinator violates the standard call-by-need ordering, just as flip(<**>) violates the standard left-to-right ordering, but people don't generally find ($!) unintuitive... Of course, both are CPS transformations for the sake of controlling order of evaluation. The ($!) and flip(<**>) versions allow this transformation to be implicit by retaining the usual direct-style ordering of application; whereas flip($!) and (<**>) make the CPS ordering of application explicit. Reasoning in CPS doesn't bother me, but I think it's more elegant to be locally consistent about which style is being used. -- Live well, ~wren