stdxdecimal 0.5.0

Decimal Type for Phobos

This code is a work in progress for a new type Decimal that follows the "General Decimal Arithmetic Specification" http://speleotrove.com/decimal/decarith.html

Example

import stdxdecimal;

void main()
{
    auto d1 = decimal("1.23");
    auto d2 = decimal("1.23E-4");
    auto d3 = decimal("1.23E4");

    assert(d1.toString() == "1.23");
    assert(d2.toString() == "0.000123");
    assert(d3.toString() == "12300");

    auto d4 = d1 + d2;
    assert(d4.toString() == "1.230123");

    auto d5 = d3 - d1;
    assert(d5.toString() == "12298.87");

    auto d6 = decimal!(HighPrecision)("1.000000000000000000000000000000000000000000000000001");
    auto d7 = decimal!(HighPrecision)("1E-51");
    auto d8 = d6 + d7;
    assert(d8.toString() == "1.000000000000000000000000000000000000000000000000002");
}

Current Features

Current Performance

Run on a 15", 2015 Macbook Pro, (rounded to the nearest ms; test values purposely avoid rounding, which is the slowest part by far)

Run It Yourself

D: ldc2 -O -release bench.d source/stdxdecimal/package.d && ./bench

Python:

import timeit

timeit.timeit("c = a + b", setup="from decimal import Decimal; a = Decimal(10000.12); b = Decimal(5000000); c = None", number=5000000)
timeit.timeit("c = a + b", setup="from decimal import Decimal; a = Decimal(1000000000000000000000000000000000000000000000000000000000000000); b = Decimal(5000000000000000000000000000000000000000000000000000000000000000); c = None", number=5000000)
timeit.timeit("c = a - b", setup="from decimal import Decimal; a = Decimal(10000.12); b = Decimal(5000000); c = None", number=5000000)
timeit.timeit("c = a - b", setup="from decimal import Decimal; a = Decimal('10000000000000000000000000000000000000000000000000000000000000.12'); b = Decimal('5000000000000000000000000000000000000000000000000000000000000000'); c = None", number=5000000)
timeit.timeit("c = a * b", setup="from decimal import Decimal; a = Decimal(10000.12); b = Decimal(5000000); c = None", number=5000000)
timeit.timeit("c = a * b", setup="from decimal import Decimal; a = Decimal('10000000000000000000000000000000000000000000000000000000000000.12'); b = Decimal('5000000000000000000000000000000000000000000000000000000000000000'); c = None", number=5000000)
timeit.timeit("c = a / b", setup="from decimal import Decimal; a = Decimal(10000.12); b = Decimal(5000000); c = None", number=1000000)
timeit.timeit("c = a / b", setup="from decimal import Decimal; a = Decimal('10000000000000000000000000000000000000000000000000000000000000.12'); b = Decimal('5000000000000000000000000000000000000000000000000000000000000000'); c = None", number=1000000)
timeit.timeit("c = sorted(a)", setup="from decimal import Decimal;import random; a = [Decimal(random.randint(-10000000, 10000000) * random.random()) for x in range(1000000)]", number=1)
timeit.timeit("c = sorted(a)", setup="from decimal import Decimal;import random; a = [Decimal(random.randint(-100000000000000000000000000000000000000000000000000, 100000000000000000000000000000000000000000000000000) * random.random()) for x in range(1000000)]", number=1)