Newtonsoft.Json\Utilities\StringUtils.cs

#region License

// Copyright (c) 2007 James Newton-King

//

// 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.

#endregion

using System;

using System.Collections.Generic;

using System.IO;

using System.Text;

using System.Text.RegularExpressions;

using System.Linq;

using System.Globalization;

namespace Newtonsoft.Json.Utilities

{

  internal static class StringUtils

  {

    public const string CarriageReturnLineFeed = "\r\n";

    public const string Empty = "";

    public const char CarriageReturn = '\r';

    public const char LineFeed = '\n';

    public const char Tab = '\t';

    //public static string FormatWith(this string format, params object[] args)

    //{

    //  return FormatWith(format, null, args);

    //}

    public static string FormatWith(this string format, IFormatProvider provider, params object[] args)

    {

      ValidationUtils.ArgumentNotNull(format, "format");

      return string.Format(provider, format, args);

    }

    /// <summary>

    /// Determines whether the string contains white space.

    /// </summary>

    /// <param name="s">The string to test for white space.</param>

    /// <returns>

    /// 	<c>true</c> if the string contains white space; otherwise, <c>false</c>.

    /// </returns>

    public static bool ContainsWhiteSpace(string s)

    {

      if (s == null)

        throw new ArgumentNullException("s");

      for (int i = 0; i < s.Length; i++)

      {

        if (char.IsWhiteSpace(s[i]))

          return true;

      }

      return false;

    }

    /// <summary>

    /// Determines whether the string is all white space. Empty string will return false.

    /// </summary>

    /// <param name="s">The string to test whether it is all white space.</param>

    /// <returns>

    /// 	<c>true</c> if the string is all white space; otherwise, <c>false</c>.

    /// </returns>

    public static bool IsWhiteSpace(string s)

    {

      if (s == null)

        throw new ArgumentNullException("s");

      if (s.Length == 0)

        return false;

      for (int i = 0; i < s.Length; i++)

      {

        if (!char.IsWhiteSpace(s[i]))

          return false;

      }

      return true;

    }

    /// <summary>

    /// Ensures the target string ends with the specified string.

    /// </summary>

    /// <param name="target">The target.</param>

    /// <param name="value">The value.</param>

    /// <returns>The target string with the value string at the end.</returns>

    public static string EnsureEndsWith(string target, string value)

    {

      if (target == null)

        throw new ArgumentNullException("target");

      if (value == null)

        throw new ArgumentNullException("value");

      if (target.Length >= value.Length)

      {

        if (string.Compare(target, target.Length - value.Length, value, 0, value.Length, StringComparison.OrdinalIgnoreCase) ==

                        0)

          return target;

        string trimmedString = target.TrimEnd(null);

        if (string.Compare(trimmedString, trimmedString.Length - value.Length, value, 0, value.Length,

                        StringComparison.OrdinalIgnoreCase) == 0)

          return target;

      }

      return target + value;

    }

    public static bool IsNullOrEmptyOrWhiteSpace(string s)

    {

      if (string.IsNullOrEmpty(s))

        return true;

      else if (IsWhiteSpace(s))

        return true;

      else

        return false;

    }

    /// <summary>

    /// Perform an action if the string is not null or empty.

    /// </summary>

    /// <param name="value">The value.</param>

    /// <param name="action">The action to perform.</param>

    public static void IfNotNullOrEmpty(string value, Action<string> action)

    {

      IfNotNullOrEmpty(value, action, null);

    }

    private static void IfNotNullOrEmpty(string value, Action<string> trueAction, Action<string> falseAction)

    {

      if (!string.IsNullOrEmpty(value))

      {

        if (trueAction != null)

          trueAction(value);

      }

      else

      {

        if (falseAction != null)

          falseAction(value);

      }

    }

    /// <summary>

    /// Indents the specified string.

    /// </summary>

    /// <param name="s">The string to indent.</param>

    /// <param name="indentation">The number of characters to indent by.</param>

    /// <returns></returns>

    public static string Indent(string s, int indentation)

    {

      return Indent(s, indentation, ' ');

    }

    /// <summary>

    /// Indents the specified string.

    /// </summary>

    /// <param name="s">The string to indent.</param>

    /// <param name="indentation">The number of characters to indent by.</param>

    /// <param name="indentChar">The indent character.</param>

    /// <returns></returns>

    public static string Indent(string s, int indentation, char indentChar)

    {

      if (s == null)

        throw new ArgumentNullException("s");

      if (indentation <= 0)

        throw new ArgumentException("Must be greater than zero.", "indentation");

      StringReader sr = new StringReader(s);

      StringWriter sw = new StringWriter(CultureInfo.InvariantCulture);

      ActionTextReaderLine(sr, sw, delegate(TextWriter tw, string line)

      {

        tw.Write(new string(indentChar, indentation));

        tw.Write(line);

      });

      return sw.ToString();

    }

    private delegate void ActionLine(TextWriter textWriter, string line);

    private static void ActionTextReaderLine(TextReader textReader, TextWriter textWriter, ActionLine lineAction)

    {

      string line;

      bool firstLine = true;

      while ((line = textReader.ReadLine()) != null)

      {

        if (!firstLine)

          textWriter.WriteLine();

        else

          firstLine = false;

        lineAction(textWriter, line);

      }

    }

    /// <summary>

    /// Numbers the lines.

    /// </summary>

    /// <param name="s">The string to number.</param>

    /// <returns></returns>

    public static string NumberLines(string s)

    {

      if (s == null)

        throw new ArgumentNullException("s");

      StringReader sr = new StringReader(s);

      StringWriter sw = new StringWriter(CultureInfo.InvariantCulture);

      int lineNumber = 1;

      ActionTextReaderLine(sr, sw, delegate(TextWriter tw, string line)

      {

        tw.Write(lineNumber.ToString(CultureInfo.InvariantCulture).PadLeft(4));

        tw.Write(". ");

        tw.Write(line);

        lineNumber++;

      });

      return sw.ToString();

    }

    /// <summary>

    /// Nulls an empty string.

    /// </summary>

    /// <param name="s">The string.</param>

    /// <returns>Null if the string was null, otherwise the string unchanged.</returns>

    public static string NullEmptyString(string s)

    {

      return (string.IsNullOrEmpty(s)) ? null : s;

    }

    public static string ReplaceNewLines(string s, string replacement)

    {

      StringReader sr = new StringReader(s);

      StringBuilder sb = new StringBuilder();

      bool first = true;

      string line;

      while ((line = sr.ReadLine()) != null)

      {

        if (first)

          first = false;

        else

          sb.Append(replacement);

        sb.Append(line);

      }

      return sb.ToString();

    }

    public static string Truncate(string s, int maximumLength)

    {

      return Truncate(s, maximumLength, "...");

    }

    public static string Truncate(string s, int maximumLength, string suffix)

    {

      if (suffix == null)

        throw new ArgumentNullException("suffix");

      if (maximumLength <= 0)

        throw new ArgumentException("Maximum length must be greater than zero.", "maximumLength");

      int subStringLength = maximumLength - suffix.Length;

      if (subStringLength <= 0)

        throw new ArgumentException("Length of suffix string is greater or equal to maximumLength");

      if (s != null && s.Length > maximumLength)

      {

        string truncatedString = s.Substring(0, subStringLength);

        // incase the last character is a space

        truncatedString = truncatedString.Trim();

        truncatedString += suffix;

        return truncatedString;

      }

      else

      {

        return s;

      }

    }

    public static StringWriter CreateStringWriter(int capacity)

    {

      StringBuilder sb = new StringBuilder(capacity);

      StringWriter sw = new StringWriter(sb, CultureInfo.InvariantCulture);

      return sw;

    }

    public static int? GetLength(string value)

    {

      if (value == null)

        return null;

      else

        return value.Length;

    }

    public static string ToCharAsUnicode(char c)

    {

      char h1 = MathUtils.IntToHex((c >> 12) & '\x000f');

      char h2 = MathUtils.IntToHex((c >> 8) & '\x000f');

      char h3 = MathUtils.IntToHex((c >> 4) & '\x000f');

      char h4 = MathUtils.IntToHex(c & '\x000f');

      return new string(new[] { '\\', 'u', h1, h2, h3, h4 });

    }

    public static void WriteCharAsUnicode(TextWriter writer, char c)

    {

      ValidationUtils.ArgumentNotNull(writer, "writer");

      char h1 = MathUtils.IntToHex((c >> 12) & '\x000f');

      char h2 = MathUtils.IntToHex((c >> 8) & '\x000f');

      char h3 = MathUtils.IntToHex((c >> 4) & '\x000f');

      char h4 = MathUtils.IntToHex(c & '\x000f');

      writer.Write('\\');

      writer.Write('u');

      writer.Write(h1);

      writer.Write(h2);

      writer.Write(h3);

      writer.Write(h4);

    }

    public static TSource ForgivingCaseSensitiveFind<TSource>(this IEnumerable<TSource> source, Func<TSource, string> valueSelector, string testValue)

    {

      if (source == null)

        throw new ArgumentNullException("source");

      if (valueSelector == null)

        throw new ArgumentNullException("valueSelector");

      var caseInsensitiveResults = source.Where(s => string.Compare(valueSelector(s), testValue, StringComparison.OrdinalIgnoreCase) == 0);

      if (caseInsensitiveResults.Count() <= 1)

      {

        return caseInsensitiveResults.SingleOrDefault();

      }

      else

      {

        // multiple results returned. now filter using case sensitivity

        var caseSensitiveResults = source.Where(s => string.Compare(valueSelector(s), testValue, StringComparison.Ordinal) == 0);

        return caseSensitiveResults.SingleOrDefault();

      }

    }

  }

}