source: trunk/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/Editor/UnicodeNewline.cs @ 15888

//
// UnicodeNewline.cs
//
// Author:
//       Mike KrÃŒger <mkrueger@xamarin.com>
//
// Copyright (c) 2013 Xamarin Inc. (http://xamarin.com)
//
// 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.
using System;

namespace ICSharpCode.NRefactory
{
  public enum UnicodeNewline {
    Unknown,

    /// <summary>
    /// Line Feed, U+000A
    /// </summary>
    LF = 0x0A,


    CRLF = 0x0D0A,

    /// <summary>
    /// Carriage Return, U+000D
    /// </summary>
    CR = 0x0D,

    /// <summary>
    /// Next Line, U+0085
    /// </summary>
    NEL = 0x85,

    /// <summary>
    /// Vertical Tab, U+000B
    /// </summary>
    VT = 0x0B,

    /// <summary>
    /// Form Feed, U+000C
    /// </summary>
    FF = 0x0C,

    /// <summary>
    /// Line Separator, U+2028
    /// </summary>
    LS = 0x2028,

    /// <summary>
    /// Paragraph Separator, U+2029
    /// </summary>
    PS = 0x2029
  }


  /// <summary>
  /// Defines unicode new lines according to  Unicode Technical Report #13
  /// http://www.unicode.org/standard/reports/tr13/tr13-5.html
  /// </summary>
  public static class NewLine
  {
    /// <summary>
    /// Carriage Return, U+000D
    /// </summary>
    public const char CR = (char)0x0D;

    /// <summary>
    /// Line Feed, U+000A
    /// </summary>
    public const char LF = (char)0x0A;

    /// <summary>
    /// Next Line, U+0085
    /// </summary>
    public const char NEL = (char)0x85;

    /// <summary>
    /// Vertical Tab, U+000B
    /// </summary>
    public const char VT  = (char)0x0B;

    /// <summary>
    /// Form Feed, U+000C
    /// </summary>
    public const char FF  = (char)0x0C;

    /// <summary>
    /// Line Separator, U+2028
    /// </summary>
    public const char LS  = (char)0x2028;

    /// <summary>
    /// Paragraph Separator, U+2029
    /// </summary>
    public const char PS  = (char)0x2029;

    /// <summary>
    /// Determines if a char is a new line delimiter.
    /// </summary>
    /// <returns>0 == no new line, otherwise it returns either 1 or 2 depending of the length of the delimiter.</returns>
    /// <param name="curChar">The current character.</param>
    /// <param name="nextChar">A callback getting the next character (may be null).</param>
    public static int GetDelimiterLength (char curChar, Func<char> nextChar = null)
    {
      if (curChar == CR) {
        if (nextChar != null && nextChar () == LF)
          return 2;
        return 1;
      }

      if (curChar == LF || curChar == NEL || curChar == VT || curChar == FF || curChar == LS || curChar == PS)
        return 1;
      return 0;
    }

    /// <summary>
    /// Determines if a char is a new line delimiter.
    /// </summary>
    /// <returns>0 == no new line, otherwise it returns either 1 or 2 depending of the length of the delimiter.</returns>
    /// <param name="curChar">The current character.</param>
    /// <param name="nextChar">The next character (if != LF then length will always be 0 or 1).</param>
    public static int GetDelimiterLength (char curChar, char nextChar)
    {
      if (curChar == CR) {
        if (nextChar == LF)
          return 2;
        return 1;
      }

      if (curChar == LF || curChar == NEL || curChar == VT || curChar == FF || curChar == LS || curChar == PS)
        return 1;
      return 0;
    }


    /// <summary>
    /// Determines if a char is a new line delimiter.
    /// </summary>
    /// <returns>0 == no new line, otherwise it returns either 1 or 2 depending of the length of the delimiter.</returns>
    /// <param name="curChar">The current character.</param>
    /// <param name = "length">The length of the delimiter</param>
    /// <param name = "type">The type of the delimiter</param>
    /// <param name="nextChar">A callback getting the next character (may be null).</param>
    public static bool TryGetDelimiterLengthAndType (char curChar, out int length, out UnicodeNewline type, Func<char> nextChar = null)
    {
      if (curChar == CR) {
        if (nextChar != null && nextChar () == LF) {
          length = 2;
          type = UnicodeNewline.CRLF;
        } else {
          length = 1;
          type = UnicodeNewline.CR;

        }
        return true;
      }

      switch (curChar) {
      case LF:
        type = UnicodeNewline.LF;
        length = 1;
        return true;
      case NEL:
        type = UnicodeNewline.NEL;
        length = 1;
        return true;
      case VT:
        type = UnicodeNewline.VT;
        length = 1;
        return true;
      case FF:
        type = UnicodeNewline.FF;
        length = 1;
        return true;
      case LS:
        type = UnicodeNewline.LS;
        length = 1;
        return true;
      case PS:
        type = UnicodeNewline.PS;
        length = 1;
        return true;
      }
      length = -1;
      type = UnicodeNewline.Unknown;
      return false;
    }

    /// <summary>
    /// Determines if a char is a new line delimiter.
    /// </summary>
    /// <returns>0 == no new line, otherwise it returns either 1 or 2 depending of the length of the delimiter.</returns>
    /// <param name="curChar">The current character.</param>
    /// <param name = "length">The length of the delimiter</param>
    /// <param name = "type">The type of the delimiter</param>
    /// <param name="nextChar">The next character (if != LF then length will always be 0 or 1).</param>
    public static bool TryGetDelimiterLengthAndType (char curChar, out int length, out UnicodeNewline type, char nextChar)
    {
      if (curChar == CR) {
        if (nextChar == LF) {
          length = 2;
          type = UnicodeNewline.CRLF;
        } else {
          length = 1;
          type = UnicodeNewline.CR;

        }
        return true;
      }

      switch (curChar) {
      case LF:
        type = UnicodeNewline.LF;
        length = 1;
        return true;
      case NEL:
        type = UnicodeNewline.NEL;
        length = 1;
        return true;
      case VT:
        type = UnicodeNewline.VT;
        length = 1;
        return true;
      case FF:
        type = UnicodeNewline.FF;
        length = 1;
        return true;
      case LS:
        type = UnicodeNewline.LS;
        length = 1;
        return true;
      case PS:
        type = UnicodeNewline.PS;
        length = 1;
        return true;
      }
      length = -1;
      type = UnicodeNewline.Unknown;
      return false;
    }

    /// <summary>
    /// Gets the new line type of a given char/next char.
    /// </summary>
    /// <returns>0 == no new line, otherwise it returns either 1 or 2 depending of the length of the delimiter.</returns>
    /// <param name="curChar">The current character.</param>
    /// <param name="nextChar">A callback getting the next character (may be null).</param>
    public static UnicodeNewline GetDelimiterType (char curChar, Func<char> nextChar = null)
    {
      switch (curChar) {
        case CR:
        if (nextChar != null && nextChar () == LF)
          return UnicodeNewline.CRLF;
        return UnicodeNewline.CR;
        case LF:
        return UnicodeNewline.LF;
        case NEL:
        return UnicodeNewline.NEL;
        case VT:
        return UnicodeNewline.VT;
        case FF:
        return UnicodeNewline.FF;
        case LS:
        return UnicodeNewline.LS;
        case PS:
        return UnicodeNewline.PS;
      }
      return UnicodeNewline.Unknown;
    }

    /// <summary>
    /// Gets the new line type of a given char/next char.
    /// </summary>
    /// <returns>0 == no new line, otherwise it returns either 1 or 2 depending of the length of the delimiter.</returns>
    /// <param name="curChar">The current character.</param>
    /// <param name="nextChar">The next character (if != LF then length will always be 0 or 1).</param>
    public static UnicodeNewline GetDelimiterType (char curChar, char nextChar)
    {
      switch (curChar) {
      case CR:
        if (nextChar == LF)
          return UnicodeNewline.CRLF;
        return UnicodeNewline.CR;
      case LF:
        return UnicodeNewline.LF;
      case NEL:
        return UnicodeNewline.NEL;
      case VT:
        return UnicodeNewline.VT;
      case FF:
        return UnicodeNewline.FF;
      case LS:
        return UnicodeNewline.LS;
      case PS:
        return UnicodeNewline.PS;
      }
      return UnicodeNewline.Unknown;
    }

    /// <summary>
    /// Determines if a char is a new line delimiter. 
    /// 
    /// Note that the only 2 char wide new line is CR LF and both chars are new line
    /// chars on their own. For most cases GetDelimiterLength is the better choice.
    /// </summary>
    public static bool IsNewLine(char ch)
    {
      return
        ch == NewLine.CR ||
        ch == NewLine.LF ||
        ch == NewLine.NEL ||
        ch == NewLine.VT ||
        ch == NewLine.FF ||
        ch == NewLine.LS ||
        ch == NewLine.PS;
    }

    /// <summary>
    /// Gets the new line as a string.
    /// </summary>
    public static string GetString (UnicodeNewline newLine)
    {
      switch (newLine) {
      case UnicodeNewline.Unknown:
        return "";
      case UnicodeNewline.LF:
        return "\n";
      case UnicodeNewline.CRLF:
        return "\r\n";
      case UnicodeNewline.CR:
        return "\r";
      case UnicodeNewline.NEL:
        return "\u0085";
      case UnicodeNewline.VT:
        return "\u000B";
      case UnicodeNewline.FF:
        return "\u000C";
      case UnicodeNewline.LS:
        return "\u2028";
      case UnicodeNewline.PS:
        return "\u2029";
      default:
        throw new ArgumentOutOfRangeException ();
      }
    }
  }
}