^ ( x y -- x^y )
Factor handbook » The language » Numbers » Mathematical functions » Powers and logarithms

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Vocabulary
math.functions

Inputs

x	a number
y	a number

Outputs

x^y

a number

Word description
Raises x to the power of y. If y is an integer the answer is computed exactly, otherwise a floating point approximation is used.

Notes
Returns NaN for indeterminate real powers: zero or infinity raised to zero, and positive or negative one raised to either infinity. A NaN real operand also produces NaN. These rules apply to ^; the low-level fpow word follows the platform math library.

Definition

USING: combinators kernel math math.functions.private math.libm
;

IN: math.functions

: ^ ( x y -- x^y )
    {
        { [ 2dup indeterminate-real-power? ] [ 2drop 0/0. ] }
        { [ over zero? ] [ 0^ ] }
        { [ dup integer? ] [ ^integer ] }
        { [ 2dup real^? ] [ [ >float ] bi@ fpow ] }
        [ ^complex ]
    } cond ; inline