Exponentiation with infix operators in (or operating on) the base: Difference between revisions
Exponentiation with infix operators in (or operating on) the base (view source)
Revision as of 10:25, 7 November 2020
, 3 years agoAdded Go
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5 2 -x**p 25 -(x)**p 25 (-x)**p 25 -(x**p) -25
5 3 -x**p -125 -(x)**p -125 (-x)**p -125 -(x**p) -125
</pre>
=={{header|Go}}==
Go uses the math.Pow function for exponentiation and doesn't support operator overloading at all. Consequently, it is not possible to conjure up an infix operator to do the same job.
Perhaps the closest we can get is to define a derived type (''float'' say) based on float64 and then give it a method with a short name (''p'' say) to provide exponentiation.
This looks odd but is perfectly workable as the following example shows. However, as a method call, ''x.p'' is always going to take precedence over the unary minus operator and will always require the exponent to be enclosed in parentheses.
Note that we can't call the method ''↑'' (or similar) because identifiers in Go must begin with a Unicode letter and using a non-ASCII symbol would be awkward to type on some keyboards in any case.
<lang go>package main
import (
"fmt"
"math"
)
type float float64
func (f float) p(e float) float { return float(math.Pow(float64(f), float64(e))) }
func main() {
ops := []string{"-x.p(e)", "-(x).p(e)", "(-x).p(e)", "-(x.p(e))"}
for _, x := range []float{float(-5), float(5)} {
for _, e := range []float{float(2), float(3)} {
fmt.Printf("x = %2.0f e = %0.0f | ", x, e)
fmt.Printf("%s = %4.0f | ", ops[0], -x.p(e))
fmt.Printf("%s = %4.0f | ", ops[1], -(x).p(e))
fmt.Printf("%s = %4.0f | ", ops[2], (-x).p(e))
fmt.Printf("%s = %4.0f\n", ops[3], -(x.p(e)))
}
}
}</lang>
{{out}}
<pre>
x = -5 e = 2 | -x.p(e) = -25 | -(x).p(e) = -25 | (-x).p(e) = 25 | -(x.p(e)) = -25
x = -5 e = 3 | -x.p(e) = 125 | -(x).p(e) = 125 | (-x).p(e) = 125 | -(x.p(e)) = 125
x = 5 e = 2 | -x.p(e) = -25 | -(x).p(e) = -25 | (-x).p(e) = 25 | -(x.p(e)) = -25
x = 5 e = 3 | -x.p(e) = -125 | -(x).p(e) = -125 | (-x).p(e) = -125 | -(x.p(e)) = -125
</pre>
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x is 5, p is 3, -x^p is-125, -(x)^p is -125, (-x)^p is -125, -(x^p) is -125
</pre>
=={{header|Phix}}==
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