globalization: parsing and formatting helpers

Signed-off-by: Christoph Ruegg <git@cdrnet.ch>

src/MathNet.Numerics.4.5.resharper

@@ -790,7 +790,9 @@ Bluestein
         <WRAP_OBJECT_AND_COLLECTION_INITIALIZER_STYLE>CHOP_ALWAYS</WRAP_OBJECT_AND_COLLECTION_INITIALIZER_STYLE>
         <WRAP_PARAMETERS_STYLE>CHOP_IF_LONG</WRAP_PARAMETERS_STYLE>
       </FormatSettings>
-      <UsingsSettings />
+      <UsingsSettings>
+        <AddImportsToDeepestScope>True</AddImportsToDeepestScope>
+      </UsingsSettings>
       <Naming2>
         <ExceptionName IsNull="False">
         </ExceptionName>

src/Numerics/GlobalizationHelper.cs

@@ -0,0 +1,162 @@
+// <copyright file="GlobalizationHelper.cs" company="Math.NET">
+// Math.NET Numerics, part of the Math.NET Project
+// http://mathnet.opensourcedotnet.info
+//
+// Copyright (c) 2009 Math.NET
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the "Software"), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+// </copyright>
+
+namespace MathNet.Numerics
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Globalization;
+
+    /// <summary>
+    /// Globalized String Handling Helpers
+    /// </summary>
+    internal static class GlobalizationHelper
+    {
+        /// <summary>
+        /// Tries to get a <see cref="CultureInfo"/> from the format provider,
+        /// returning the current culture if it fails.
+        /// </summary>
+        /// <param name="formatProvider">
+        /// An <see cref="IFormatProvider"/> that supplies culture-specific
+        /// formatting information.
+        /// </param>
+        /// <returns>A <see cref="CultureInfo"/> instance.</returns>
+        internal static CultureInfo GetCultureInfo(this IFormatProvider formatProvider)
+        {
+            if (formatProvider == null)
+            {
+                return CultureInfo.CurrentCulture;
+            }
+
+            return (formatProvider as CultureInfo)
+                   ?? (formatProvider.GetFormat(typeof(CultureInfo)) as CultureInfo)
+                      ?? CultureInfo.CurrentCulture;
+        }
+
+        /// <summary>
+        /// Tries to get a <see cref="NumberFormatInfo"/> from the format
+        /// provider, returning the current culture if it fails.
+        /// </summary>
+        /// <param name="formatProvider">
+        /// An <see cref="IFormatProvider"/> that supplies culture-specific
+        /// formatting information.
+        /// </param>
+        /// <returns>A <see cref="NumberFormatInfo"/> instance.</returns>
+        internal static NumberFormatInfo GetNumberFormatInfo(this IFormatProvider formatProvider)
+        {
+            return NumberFormatInfo.GetInstance(formatProvider);
+        }
+
+        /// <summary>
+        /// Tries to get a <see cref="TextInfo"/> from the format provider, returning the current culture if it fails.
+        /// </summary>
+        /// <param name="formatProvider">
+        /// An <see cref="IFormatProvider"/> that supplies culture-specific
+        /// formatting information.
+        /// </param>
+        /// <returns>A <see cref="TextInfo"/> instance.</returns>
+        internal static TextInfo GetTextInfo(this IFormatProvider formatProvider)
+        {
+            return (formatProvider as TextInfo)
+                   ?? GetCultureInfo(formatProvider).TextInfo;
+        }
+
+        /// <summary>
+        /// Globalized Parsing: Tokenize a node by splitting it into several nodes.
+        /// </summary>
+        /// <param name="node">Node that contains the trimmed string to be tokenized.</param>
+        /// <param name="keywords">List of keywords to tokenize by.</param>
+        /// <param name="skip">keywords to skip looking for (because they've already been handled).</param>
+        internal static void Tokenize(LinkedListNode<string> node, string[] keywords, int skip)
+        {
+            for (int i = skip; i < keywords.Length; i++)
+            {
+                var keyword = keywords[i];
+                int indexOfKeyword;
+                while ((indexOfKeyword = node.Value.IndexOf(keyword)) >= 0)
+                {
+                    if (indexOfKeyword != 0)
+                    {
+                        // separate part before the token, process recursively
+                        string partBeforeKeyword = node.Value.Substring(0, indexOfKeyword).Trim();
+                        Tokenize(node.List.AddBefore(node, partBeforeKeyword), keywords, i + 1);
+
+                        // continue processing the rest iteratively
+                        node.Value = node.Value.Substring(indexOfKeyword);
+                    }
+
+                    if (keyword.Length == node.Value.Length)
+                    {
+                        return;
+                    }
+
+                    // separate the token, done
+                    string partAfterKeyword = node.Value.Substring(keyword.Length).Trim();
+                    node.List.AddBefore(node, keyword);
+
+                    // continue processing the rest on the right iteratively
+                    node.Value = partAfterKeyword;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Globalized Parsing: Parse a double number
+        /// </summary>
+        /// <param name="token">First token of the number.</param>
+        /// <param name="culture">Culture Info.</param>
+        /// <returns></returns>
+        /// <exception cref="FormatException" />
+        internal static double ParseDouble(ref LinkedListNode<string> token, CultureInfo culture)
+        {
+            // in case the + and - in scientific notation are separated, join them back together.
+            if (token.Value.EndsWith("e", true, culture))
+            {
+                if (token.Next == null || token.Next.Next == null)
+                {
+                    throw new FormatException();
+                }
+
+                token.Value = token.Value + token.Next.Value + token.Next.Next.Value;
+
+                var list = token.List;
+                list.Remove(token.Next.Next);
+                list.Remove(token.Next);
+            }
+
+            double value;
+            if (!Double.TryParse(token.Value, NumberStyles.Any, culture, out value))
+            {
+                throw new FormatException();
+            }
+
+            token = token.Next;
+            return value;
+        }
+    }
+}

src/Numerics/Numerics.csproj

@@ -63,6 +63,7 @@
     <Compile Include="IntegralTransforms\Algorithms\DiscreteHartleyTransform.Naive.cs" />
     <Compile Include="IntegralTransforms\Algorithms\DiscreteHartleyTransform.Options.cs" />
     <Compile Include="IntegralTransforms\HartleyOptions.cs" />
+    <Compile Include="GlobalizationHelper.cs" />
     <Compile Include="Interpolation\Algorithms\EquidistantPolynomialInterpolation.cs" />
     <Compile Include="IPrecisionSupport.cs" />
     <Compile Include="IntegralTransforms\Algorithms\DiscreteFourierTransform.Options.cs" />