root/trunk/etc/bigint/bigint_int.d

module etc.bigint.bigint_int;
import etc.bigint.exception;
import etc.bigint.multiply;
import etc.bigint.radix;
private import std.c.stdlib;
private import std.math;
private import std.string;

/*

Copyright (c) 2004, Arcane Jill

All rights reserved. Intellectual Property Me Arse!

Redistribution and use in source and binary forms, with or without modification, are permitted
provided that the following conditions are met:

   * Redistributions of source code must retain the above copyright notice, the phrase
     "Intellectual Property Me Arse!", this list of conditions, and the following disclaimer.
   * Redistributions in binary form must reproduce the above copyright notice, the phrase
     "Intellectual Property Me Arse!", this list of conditions and the following disclaimer
     in the documentation and/or other materials provided with the distribution.
   * The name Arcane Jill may not be used to endorse or promote products derived from this
     software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER,
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED, AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
OF SUCH DAMAGE.

*/

class Int
{
    unittest
    {
        Int a,b,c,d;

        //------------------------------------------
        // Test comparisons
        a = new Int(0xAAAAAAAA);
        b = new Int(0xAAAAAAAA);
        c = new Int(0xCCCCCCCC);
        d = new Int("0x00000001AAAAAAAA");
        assert(a == b);
        assert(a < c);
        assert(c > a);
        assert(a < d);
        assert(d > a);
        d = new Int(-1);
        assert(d < a);

        //------------------------------------------
        // Test add and subtract
        a = b + c;
        d = new Int("0x0000000177777776");
        assert(a == d);
        assert(a - b == c);
        c = -d;
        assert(c+d == 0);

        //------------------------------------------
        // Test multiply and divide for small values
        a = new Int(0x11111111);
        a = -a;
        b = a * a;
        c = new Int("0x0123456787654321");
        assert(b == c);
        b = b / a;
        assert(b == a);
        a = new Int(22);
        assert(a / 7 == 3);
        assert(a % 7 == 1);
        assert(a / -7 == -3);
        assert(a % -7 == 1);
        a = -a;
        assert(a / 7 == -3);
        assert(a % 7 == -1);
        assert(a / -7 == 3);
        assert(a % -7 == -1);
        a = -a;
        b = new Int(7);
        c = -b;
        assert(divMod(a, b, d, Round.TOWARD_MINUS_INFINITY) == 3);
        assert(d == 1);
        assert(divMod(a, c, d, Round.TOWARD_MINUS_INFINITY) == -4);
        assert(d == -6);
        a = -a;
        assert(divMod(a, b, d, Round.TOWARD_MINUS_INFINITY) == -4);
        assert(d == 6);
        assert(divMod(a, c, d, Round.TOWARD_MINUS_INFINITY) == 3);
        assert(d == -1);

        //------------------------------------------
        // Test multiply and divide for large values
        a = new Int("0x0111111111111111");
        b = a * a;
        c = new Int("0x000123456789ABCDEFEDCBA987654321");
        assert(b == c);
        b = b / a;
        assert(b == a);

        //------------------------------------------
        // Test binary operations
        a = new Int("0x1234567812345678");
        uint n = a & 0xFFFFu;
        assert(n == 0x5678);
        b = a & new Int(0xFF00FF);
        assert(b == new Int(0x340078));
        c = a | 0xFFFF;
        assert(c == new Int("0x123456781234FFFF"));
        d = a ^ 0xFFFFFFFF;
        assert (d == new Int("0x12345678EDCBA987"));
        c = d & -1;
        assert(c == d);
        c = ~d;
        assert((c ^ (-1)) == d);

        //------------------------------------------
        // Test shift left and shift right
        a = new Int(0x12345678);
        b = a << 40;
        c = new Int("0x000000123456780000000000");
        assert(b == c);
        d = c << -40;
        assert(d == a);
        d = c >>> 40;
        assert(d == a);
        c = -c;
        a = -a;
        d = c << -40;
        assert(d == a);
        try
        {
            d = c >>> 40;
        }
        catch (IntException)
        {
            b = ZERO;
        }
        assert(b == 0);
        d = c >>> 0;
        assert(c == d);

        //------------------------------------------
        // Test the array-like functions

        a = new Int("0xFEDCBA98_76543210_00000000_00000000_FEDCBA98_76543210");
        assert(a[1] == 0xFEDCBA98);
        assert(a[3000] == 0);
        assert(a[0..2] == a[4..6]);
        assert(a[100..115] == a[200..215]);
        assert(a[0..4] == a[4..8]);

        //------------------------------------------
        // Test formatting

        a = new Int(123);
        assert(a.format(10, 0, 0, false, SignMode.NORMAL)           ==   "123");
        assert(a.format(10, 0, 0, false, SignMode.MINUS_SPACE_PLUS) ==  "+123");
        assert(a.format(10, 0, 0, true,  SignMode.NORMAL)           ==   "123");
        assert(a.format(10, 0, 2, false, SignMode.NORMAL)           ==  "1_23");
        assert(a.format(10, 5, 0, false, SignMode.NORMAL)           == "  123");
        assert(a.format(10, 5, 0, false, SignMode.MINUS_SPACE_PLUS) == " +123");
        assert(a.format(10, 5, 0, true,  SignMode.NORMAL)           == "00123");
        assert(a.format(10, 5, 0, true,  SignMode.MINUS_SPACE_PLUS) == "+0123");
        assert(a.format(10, 5, 2, false, SignMode.NORMAL)           == " 1_23");
        a = -a;
        assert(a.format(10, 5, 0, false, SignMode.NORMAL)           == " -123");
        assert(a.format(10, 5, 0, true,  SignMode.NORMAL)           == "-0123");
        assert(a.format(10, 5, 2, false, SignMode.NORMAL)           == "-1_23");

        a = new Int("123456");
        assert(a.toString() == "123456");
        a = new Int("0x123456");
        assert(a.toHexString() == "123456");

        a = new Int("0");
        assert (a.toString == "0");
        assert (ZERO.toString == "0");
        assert (a == ZERO);
        assert (a == new Int(0));
    }

    invariant
    {
        if (d)
        {
            uint n = d.length;
            assert(n >= 2);                 // array must be sufficiently large (2 uints)
            int s = d[n-1];
            assert((s == 0) || (s == -1));  // sign field may not contain rubbish
            if (n>2)
            {
                assert(d[n-2] != s);        // array must be minimal
            }
        }
    }

    public
    {

        // -------- Constants --------

        enum Round { TOWARD_ZERO, TOWARD_INFINITY, TOWARD_MINUS_INFINITY }

        static
        {
            Int ZERO, ONE, TWO, MINUS_ONE;
        }

        static this()
        {
            ZERO = new Int(0);
            ONE = new Int(1);
            TWO = new Int(2);
            MINUS_ONE = new Int(-1);
        }

        // -------- Constructors --------

        // Construct from an int
        this(int n)
        {
            d.length = 2;
            d[0] = n;
            d[1] = n < 0 ? -1U : 0;
        }

        static Int opCall(int n) { return new Int(n); }

        // Construct from a uint
        this(uint n)
        {
            d.length = 2;
            d[0] = n;
        }

        static Int opCall(uint n) { return new Int(n); }

        // Construct from a long
        this(long n)
        {
            d.length = 3;
            *(cast(ulong*)d) = n;
            d[2] = n < 0 ? -1U : 0;
            minimize(this);
        }

        static Int opCall(long n) { return new Int(n); }

        // Construct from a ulong
        this(ulong n)
        {
            d.length = 3;
            *(cast(ulong*)d) = n;
            minimize(this);
        }

        static Int opCall(ulong n) { return new Int(n); }

        // Construct from a float
        this(float x)
        {
            this(cast(real) x);
        }

        static Int opCall(float x) { return new Int(x); }

        // Construct from a double
        this(double x)
        {
            this(cast(real) x);
        }

        static Int opCall(double x) { return new Int(x); }

        // Construct from a real
        this(real x)
        {
            uint i;
            d.length = 4;
            bool sign = (x < 0);
            if (sign) x = -x;
            while (x > 0)
            {
                real xq = floor(x / 4294967296.0);
                real xr = x - (xq * 4294967296.0);
                d[i++] = cast(uint) xr;
                if (i == d.length-1) d.length = d.length << 1;
                x = xq;
            }
            if (sign)
            {
                bigintLLNeg(d, d, d.length);
            }
            minimize(this);
        }

        static Int opCall(real x) { return new Int(x); }

        // Construct from a string.
        this(char[] s)
        {
            this(s, uint.max);
        }

        static Int opCall(char[] s) { return new Int(s); }

        this(char[] s, uint radix)
        {
            bool isNegative = false;
            if (s.length > 1)
            {
                if (s[0] == '+')
                {
                    s = s[1..s.length];
                }
                else if (s[0] == '-')
                {
                    s = s[1..s.length];
                    isNegative = true;
                }
            }
            d = bigintFromString(s, radix);

            uint len = bigintLLMinimize(d, d.length);
            if (len == 0)
            {
                d.length = 2;
                d[] = isNegative ? -1U : 0;
            }
            else
            {
                d.length = len+1;
            }
            if (isNegative)
            {
                bigintLLNeg(d, d, d.length);
                minimize(this);
            }
        }

        static Int opCall(char[] s, uint radix) { return new Int(s, radix); }

        // Construct from a uint array. This copies by value, not by reference;
        this(uint[] x, bool isNegative)
        {
            d.length = x.length + 1;
            d[0..x.length] = x[0..x.length];
            d[x.length] = isNegative ? -1U : 0;
            minimize(this);
        }

        static Int opCall(uint[] x, bool isNegative) { return new Int(x, isNegative); }

        // -------- Conversions --------

        override
        {
            char[] toString()
            out(s)
            {
                assert(this == new Int(s));
            }
            body
            {
                return format(10, 0, 0, false, SignMode.NORMAL);
            }
        }

        char[] toHexString()
        out(s)
        {
            assert(this == new Int(s,16));
        }
        body
        {
            return format(16, 0, 8, false, SignMode.NORMAL);
        }

        int toInt()
        {
            if (isInt()) return d[0];
            return (sign) ? int.min : int.max;
        }

        uint toUint()
        {
            if (isUint()) return d[0];
            return uint.max;
        }

        long toLong()
        {
            if (isLong())
            {
                ulong lo = d[0];
                ulong hi = d[1];
                return (hi << 32) | lo;
            }
            return (sign) ? long.min : long.max;
        }

        ulong toUlong()
        {
            if (isUlong())
            {
                ulong lo = d[0];
                ulong hi = d[1];
                return (hi << 32) | lo;
            }
            return ulong.max;
        }

        float toFloat()
        {
            return toReal();
        }

        double toDouble()
        {
            return toReal();
        }

        real toReal()
        {
            if (sign) return -((-this).toReal());
            real r = 0;
            for (uint i=0; i<end; ++i)
            {
                r *= 4294967296.0;
                r += d[i];
            }
            return r;
        }

        // -------- Tests --------

        bool isInt()
        {
            if (d.length > 2) return false;
            if (sign)
            {
                return (d[0] >= 0x80000000);
            }
            else
            {
                return (d[0] < 0x80000000);
            }
        }

        bool isUint()
        {
            if (sign) return false;
            return (d.length == 2);
        }

        bool isLong()
        {
            if (d.length > 3) return false;
            if (sign)
            {
                return (d[d.length-2] >= 0x80000000);
            }
            else
            {
                return (d[d.length-2] < 0x80000000);
            }
        }

        bool isUlong()
        {
            if (sign) return false;
            return (d.length <= 3);
        }

        override
        {
            int /*I wish this was bool*/ opEquals(Object obj)
            {
                Int y = cast(Int) obj;
                assert(y);
                return d == y.d;
            }
        }

        int /*I wish this was bool*/ opEquals(int n)
        {
            return isInt() ? (n == d[0]) : 0;
        }

        int /*I wish this was bool*/ opEquals(uint n)
        {
            return isUint() ? (n == d[0]) : 0;
        }

        override
        {
            int opCmp(Object obj)
            {
                Int y = cast(Int) obj;
                assert(y);

                Int x = this;
                if (x === y) return 0;
                int xSign = x.sign;
                int ySign = y.sign;
                if (xSign < ySign) return -1;
                if (xSign > ySign) return 1;

                int r;
                int n = x.d.length;
                if (x.d.length > y.d.length)
                {
                    n = y.d.length;
                    r = bigintLLCmpAll(&x.d[y.d.length], y.sign, x.d.length - y.d.length);
                    if (r < 0) return -1;
                    if (r > 0) return 1;
                }
                if (x.d.length < y.d.length)
                {
                    r = bigintLLCmpAll(x.sign, &y.d[x.d.length], y.d.length - x.d.length);
                    if (r < 0) return -1;
                    if (r > 0) return 1;
                }
                r = bigintLLCmp(x.d, y.d, n);
                if (r < 0) return -1;
                if (r > 0) return 1;
                return 0;
            }
        }

        int opCmp(int y)
        {
            if (isInt())
            {
                int x = d[0];
                if (x == y) return 0;
                return (x < y) ? -1 : 1;
            }
            else
            {
                return opCmp(new Int(y));
            }
        }

        int opCmp(uint y)
        {
            if (isUint())
            {
                uint x = d[0];
                if (x == y) return 0;
                return (x < y) ? -1 : 1;
            }
            else