I think what you're missing is what you actually typed in the first case.
This is a type error, it will not compile or run:
chopEnds = init $ tail
The $ operator can always be rewritten as parentheses, in this case:
chopEnds = init (tail)
Which has the same incorrectly typed meaning as:
chopEnds = init tail
The "result" you pasted looks equivalent to:
chopEnds = init
Perhaps this is what you typed? In this case the argument tail it will
shadow the existing binding of the Prelude tail, which would be confusing
so with -Wall it would issue a compiler warning:
chopEnds tail = init $ tail
<interactive>:2:10: warning: [-Wname-shadowing]
This binding for ‘tail’ shadows the existing binding
imported from ‘Prelude’ (and originally defined in ‘GHC.List’)
On Mon, Jan 25, 2021 at 10:16 AM Lawrence Bottorff
I've got this
init $ tail [1,2,3] [2]
and this
chopEnds = init $ tail chopEnds [1,2,3] [1,2]
What happened? Why is it not just init $ tail [1,2,3] ?
This works fine
chopEnds2 = init . tail chopEnds2 [1,2,3] [2]
What am I missing?
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