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\DOC funpow
\TYPE {funpow : int -> ('a -> 'a) -> 'a -> 'a}
\SYNOPSIS
Iterates a function a fixed number of times.
\DESCRIBE
{funpow n f x} applies {f} to {x}, {n} times, giving the result {f (f ... (f
x)...)} where the number of {f}'s is {n}. {funpow 0 f x} returns {x}. If {n} is
negative, it is treated as zero.
\FAILURE
{funpow n f x} fails if any of the {n} applications of f fail.
\EXAMPLE
Apply {tl} three times to a list:
{
# funpow 3 tl [1;2;3;4;5];;
val it : int list = [4; 5]
}
\noindent Apply {tl} zero times:
{
# funpow 0 tl [1;2;3;4;5];;
val it : int list = [1; 2; 3; 4; 5]
}
\noindent Apply {tl} six times to a list of only five elements:
{
# funpow 6 tl [1;2;3;4;5];;
Exception: Failure "tl".
}
\ENDDOC
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