[procedure] integer-expt x y

SLIB, Guile: x^y, for integer x and non-negative integer y.

This would be introduced for optimization, although I can imagine on most Schemes expt uses optimized calculation when both args are exact integer. You can still save a couple of dispatch, though.

SRFI-94: returns x raised to the power y if that result is an exact integer; otherwise signals an error.

(integer-expt 0 y) returns 1 for y equal to 0; returns 0 for positive integer y; signals an error otherwise.