grapes-plus-grapes: Function composition operator
In garray: Generalized Array Arithmetic for Ragged Arrays with Named Margins

Description Usage Arguments Value Examples

Composite functions a and b into a(b(...)).

a %+% b

`a`	A function that can be called with one argument.
`b`	A function that can be called with one or more argument, and result of `b()` can be passed to `a()`.

A new function, whose arguments are what b() can accept, and whose result is what a() can return.

lse <- log%+%sum%+%exp
lse(1:10)
#logsumexp(1:10)	# actual logsumexp() is more sophistic
log(sum(exp(1:10)))
sum <- sd
lse(1:10)	# lse() is fixed at definition
log(sum(exp(1:10)))
(log%+%sum%+%exp)(1:10)	# now is (log%+%sd%+%exp)