FrexpTests

fn FrexpTests(comptime Float: type) type

File

Code

fn FrexpTests(comptime Float: type) type {
    return struct {
        const T = Float;
        test "normal" {
            const epsilon = 1e-6;
            var r: Frexp(T) = undefined;

            r = frexp(@as(T, 1.3));
            try expectApproxEqAbs(0.65, r.significand, epsilon);
            try expectEqual(1, r.exponent);

            r = frexp(@as(T, 78.0234));
            try expectApproxEqAbs(0.609558, r.significand, epsilon);
            try expectEqual(7, r.exponent);

            r = frexp(@as(T, -1234.5678));
            try expectEqual(11, r.exponent);
            try expectApproxEqAbs(-0.602816, r.significand, epsilon);
        }
        test "max" {
            const exponent = math.floatExponentMax(T) + 1;
            const significand = 1.0 - math.floatEps(T) / 2;
            const r: Frexp(T) = frexp(math.floatMax(T));
            try expectEqual(exponent, r.exponent);
            try expectEqual(significand, r.significand);
        }
        test "min" {
            const exponent = math.floatExponentMin(T) + 1;
            const r: Frexp(T) = frexp(math.floatMin(T));
            try expectEqual(exponent, r.exponent);
            try expectEqual(0.5, r.significand);
        }
        test "subnormal" {
            const normal_min_exponent = math.floatExponentMin(T) + 1;
            const exponent = normal_min_exponent - math.floatFractionalBits(T);
            const r: Frexp(T) = frexp(math.floatTrueMin(T));
            try expectEqual(exponent, r.exponent);
            try expectEqual(0.5, r.significand);
        }
        test "zero" {
            var r: Frexp(T) = undefined;

            r = frexp(@as(T, 0.0));
            try expectEqual(0, r.exponent);
            try expect(math.isPositiveZero(r.significand));

            r = frexp(@as(T, -0.0));
            try expectEqual(0, r.exponent);
            try expect(math.isNegativeZero(r.significand));
        }
        test "inf" {
            var r: Frexp(T) = undefined;

            r = frexp(math.inf(T));
            try expectEqual(0, r.exponent);
            try expect(math.isPositiveInf(r.significand));

            r = frexp(-math.inf(T));
            try expectEqual(0, r.exponent);
            try expect(math.isNegativeInf(r.significand));
        }
        test "nan" {
            const r: Frexp(T) = frexp(math.nan(T));
            try expect(math.isNan(r.significand));
        }
    };
}