Test integerness: Difference between revisions

=={{header|Wren}}==

{{libheader|Wren-big}}

{{libheader|Wren-complex}}

{{libheader|Wren-rat}}

{{libheader|Wren-fmt}}

The -2e120 example requires the use of BigRat to reliably determine whether it's an integer or not. Although the Num class can deal with numbers of this size and correctly identifies it as an integer, it would do the same if (say) 0.5 were added to it because integer determination is only reliable up to around 15 digits.

<lang ecmascript>import "/big" for BigRat

import "/complex" for Complex

import "/rat" for Rat

import "/fmt" for Fmt

var tests1 = [25.000000, 24.999999, 25.000100]

var tests2 = ["-2.1e120"]

var tests3 = [-5e-2, 0/0, 1/0]

var tests4 = [Complex.fromString("5.0+0.0i"), Complex.fromString("5-5i")]

var tests5 = [Rat.new(24, 8), Rat.new(-5, 1), Rat.new(17, 2)]

var tests6 = tests1 + [-5e-2]

System.print("Using exact arithmetic:\n")

for (t in tests1) {

Fmt.print(" $-9.6f is integer? $s", t, t.isInteger)

}

System.print()

for (t in tests2) {

Fmt.print(" $-9s is integer? $s", t, BigRat.new(t, 1).isInteger)

}

for (t in tests3) {

Fmt.print(" $-9.6f is integer? $s", t, t.isInteger)

}

System.print()

for (t in tests4) {

Fmt.print(" $-9s is integer? $s", t, t.real.isInteger && t.imag == 0)

}

System.print()

for (t in tests5) {

Fmt.print(" $-9s is integer? $s", t, t.isInteger)

}

System.print("\nWithin a tolerance of 0.00001:\n")

var tol = 0.00001

for (t in tests6) {

var d = (t - t.round).abs

Fmt.print(" $9.6f is integer? $s", t, d <= tol)

}</lang>

{{out}}

<pre>

Using exact arithmetic:

25.000000 is integer? true

24.999999 is integer? false

25.000100 is integer? false

-2.1e120 is integer? true

-0.050000 is integer? false

nan is integer? false

infinity is integer? false

5 + 0i is integer? true

5 - 5i is integer? false

3/1 is integer? true

-5/1 is integer? true

17/2 is integer? false

Within a tolerance of 0.00001:

25.000000 is integer? true

24.999999 is integer? true

25.000100 is integer? false

-0.050000 is integer? false

</pre>