diff options
| author |  boehmes <unknown> | 2012-09-27 17:13:43 +0200 |
|---|---|---|
| committer | boehmes <unknown> | 2012-09-27 17:13:43 +0200 |
| commit | dfb77ee06c82cf8b9c465f3a2acbc5ceb035c6e5 (patch) | |
| tree | b9396dc6b4092a75c5a31c610fba53e70f91f516 | |
| parent | 623a87c132abec61b5c74a6a00a7b162073a6a8d (diff) | |
Added BigDec as representation for (floating-point) decimal values
| -rw-r--r-- | Source/Basetypes/Basetypes.csproj | 1 | ||||
| -rwxr-xr-x | Source/Basetypes/BigDec.cs | 201 |
2 files changed, 202 insertions, 0 deletions
diff --git a/Source/Basetypes/Basetypes.csproj b/Source/Basetypes/Basetypes.csproj index ceccc5cf..a7b7cb71 100644 --- a/Source/Basetypes/Basetypes.csproj +++ b/Source/Basetypes/Basetypes.csproj @@ -148,6 +148,7 @@ <Compile Include="..\version.cs">
<Link>version.cs</Link>
</Compile>
+ <Compile Include="BigDec.cs" />
<Compile Include="BigNum.cs" />
<Compile Include="Rational.cs" />
<Compile Include="Set.cs" />
diff --git a/Source/Basetypes/BigDec.cs b/Source/Basetypes/BigDec.cs new file mode 100755 index 00000000..78b19794 --- /dev/null +++ b/Source/Basetypes/BigDec.cs @@ -0,0 +1,201 @@ +//-----------------------------------------------------------------------------
+//
+// Copyright (C) Microsoft Corporation. All Rights Reserved.
+//
+//-----------------------------------------------------------------------------
+using System;
+using System.Text;
+using System.Diagnostics.Contracts;
+
+
+namespace Microsoft.Basetypes {
+ using BIM = System.Numerics.BigInteger;
+
+
+ /// <summary>
+ /// A representation of decimal values.
+ /// </summary>
+ public struct BigDec {
+
+ // the internal representation
+ [Rep]
+ internal readonly BIM mantisse;
+ [Rep]
+ internal readonly BIM exponent;
+
+ private static readonly BIM ONE = BIM.One;
+ private static readonly BIM TEN = new BIM(10);
+
+
+ ////////////////////////////////////////////////////////////////////////////
+ // Constructors
+
+ [Pure]
+ public static BigDec FromString(string v) {
+ if (v == null) throw new FormatException();
+
+ BIM integral = BIM.Zero;
+ BIM fraction = BIM.Zero;
+ BIM exponent = BIM.Zero;
+
+ int len = v.Length;
+
+ int i = v.IndexOf('e');
+ if (i >= 0) {
+ exponent = BIM.Parse(v.Substring(i + 1, len - i));
+ len = i;
+ }
+
+ int fraction_len = 0;
+ i = v.IndexOf('.');
+ if (i >= 0) {
+ fraction = BIM.Parse(v.Substring(i + 1, len - i));
+ fraction_len = len - i;
+ len = i;
+ }
+
+ integral = BIM.Parse(v.Substring(0, len));
+
+ while (fraction_len > 0) {
+ integral = integral * TEN;
+ exponent = exponent - ONE;
+ }
+
+ return new BigDec(integral + fraction, exponent);
+ }
+
+ internal BigDec(BIM mantisse, BIM exponent) {
+ while (mantisse % TEN == BIM.Zero) {
+ mantisse = mantisse / TEN;
+ exponent = exponent + ONE;
+ }
+
+ this.mantisse = mantisse;
+ this.exponent = exponent;
+ }
+
+
+ ////////////////////////////////////////////////////////////////////////////
+ // Basic object operations
+
+ [Pure]
+ [Reads(ReadsAttribute.Reads.Nothing)]
+ public override bool Equals(object obj) {
+ if (obj == null)
+ return false;
+ if (!(obj is BigDec))
+ return false;
+
+ BigDec other = (BigDec)obj;
+ return (this.mantisse == other.mantisse && this.exponent == other.exponent);
+ }
+
+ [Pure]
+ public override int GetHashCode() {
+ return this.mantisse.GetHashCode() * 13 + this.exponent.GetHashCode();
+ }
+
+ [Pure]
+ public override string/*!*/ ToString() {
+ Contract.Ensures(Contract.Result<string>() != null);
+ return String.Format("%se%s", this.mantisse.ToString(), this.exponent.ToString());
+ }
+
+
+ ////////////////////////////////////////////////////////////////////////////
+ // Basic arithmetic operations
+
+ [Pure]
+ public static BigDec operator -(BigDec x) {
+ return new BigDec(BIM.Negate(x.mantisse), x.exponent);
+ }
+
+ [Pure]
+ public static BigDec operator +(BigDec x, BigDec y) {
+ BIM m1 = x.mantisse;
+ BIM e1 = x.exponent;
+ BIM m2 = y.mantisse;
+ BIM e2 = y.exponent;
+ if (e2 < e1) {
+ m1 = y.mantisse;
+ e1 = y.exponent;
+ m2 = x.mantisse;
+ e2 = x.exponent;
+ }
+
+ while (e2 > e1) {
+ m2 = m2 * TEN;
+ e2 = e2 - ONE;
+ }
+
+ return new BigDec(m1 + m2, e1);
+ }
+
+ [Pure]
+ public static BigDec operator -(BigDec x, BigDec y) {
+ return x + (-y);
+ }
+
+ [Pure]
+ public static BigDec operator *(BigDec x, BigDec y) {
+ return new BigDec(x.mantisse * y.mantisse, x.exponent + y.exponent);
+ }
+
+
+ ////////////////////////////////////////////////////////////////////////////
+ // Some basic comparison operations
+
+ public bool IsPositive {
+ get {
+ return (this.mantisse > BIM.Zero);
+ }
+ }
+
+ public bool IsNegative {
+ get {
+ return (this.mantisse < BIM.Zero);
+ }
+ }
+
+ public bool IsZero {
+ get {
+ return this.mantisse.IsZero;
+ }
+ }
+
+ [Pure]
+ public int CompareTo(BigDec that) {
+ BigDec d = this - that;
+
+ if (d.IsZero) {
+ return 0;
+ }
+ else if (d.IsNegative) {
+ return -1;
+ }
+ else {
+ return 1;
+ }
+ }
+
+ [Pure]
+ public static bool operator <(BigDec x, BigDec y) {
+ return x.CompareTo(y) < 0;
+ }
+
+ [Pure]
+ public static bool operator >(BigDec x, BigDec y) {
+ return x.CompareTo(y) > 0;
+ }
+
+ [Pure]
+ public static bool operator <=(BigDec x, BigDec y) {
+ return x.CompareTo(y) <= 0;
+ }
+
+ [Pure]
+ public static bool operator >=(BigDec x, BigDec y) {
+ return x.CompareTo(y) >= 0;
+ }
+ }
+}
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