StringHelpers - Clifton

/*
Copyright (c) 2005, Marc Clifton
All rights reserved.

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are permitted provided that the following conditions are met:

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  of conditions and the following disclaimer.

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  used to endorse or promote products derived from this software without specific
  prior written permission.

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*/

using System;

namespace Clifton.Tools.Strings
{
    /// <summary>
    /// Helpers for string manipulation.
    /// </summary>
    public class StringHelpers
    {
        /// <summary>
        /// Left of the first occurance of c
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="c">Return everything to the left of this character.</param>
        /// <returns>String to the left of c, or the entire string.</returns>
        public static string LeftOf(string src, char c)
        {
            string ret=src;
            int idx=src.IndexOf(c);
            if (idx != -1)
            {
                ret=src.Substring(0, idx);
            }
            return ret;
        }

        /// <summary>
        /// Left of the n'th occurance of c.
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="c">Return everything to the left n'th occurance of this character.</param>
        /// <param name="n">The occurance.</param>
        /// <returns>String to the left of c, or the entire string if not found or n is 0.</returns>
        public static string LeftOf(string src, char c, int n)
        {
            string ret=src;
            int idx=-1;
            while (n > 0)
            {
                idx=src.IndexOf(c, idx+1);
                if (idx==-1)
                {
                    break;
                }
                --n;
            }
            if (idx != -1)
            {
                ret=src.Substring(0, idx);
            }
            return ret;
        }

        /// <summary>
        /// Right of the first occurance of c
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="c">The search char.</param>
        /// <returns>Returns everything to the right of c, or an empty string if c is not found.</returns>
        public static string RightOf(string src, char c)
        {
            string ret=String.Empty;
            int idx=src.IndexOf(c);
            if (idx != -1)
            {
                ret=src.Substring(idx+1);
            }
            return ret;
        }

        /// <summary>
        /// Right of the n'th occurance of c
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="c">The search char.</param>
        /// <param name="n">The occurance.</param>
        /// <returns>Returns everything to the right of c, or an empty string if c is not found.</returns>
        public static string RightOf(string src, char c, int n)
        {
            string ret=String.Empty;
            int idx=-1;
            while (n > 0)
            {
                idx=src.IndexOf(c, idx+1);
                if (idx==-1)
                {
                    break;
                }
                --n;
            }

            if (idx != -1)
            {
                ret=src.Substring(idx+1);
            }

            return ret;
        }

        /// <summary>
        /// Returns everything to the left of the righmost char c.
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="c">The search char.</param>
        /// <returns>Everything to the left of the rightmost char c, or the entire string.</returns>
        public static string LeftOfRightmostOf(string src, char c)
        {
            string ret=src;
            int idx=src.LastIndexOf(c);
            if (idx != -1)
            {
                ret=src.Substring(0, idx);
            }
            return ret;
        }

        /// <summary>
        /// Returns everything to the right of the rightmost char c.
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="c">The seach char.</param>
        /// <returns>Returns everything to the right of the rightmost search char, or an empty string.</returns>
        public static string RightOfRightmostOf(string src, char c)
        {
            string ret=String.Empty;
            int idx=src.LastIndexOf(c);
            if (idx != -1)
            {
                ret=src.Substring(idx+1);
            }
            return ret;
        }

        /// <summary>
        /// Returns everything between the start and end chars, exclusive.
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="start">The first char to find.</param>
        /// <param name="end">The end char to find.</param>
        /// <returns>The string between the start and stop chars, or an empty string if not found.</returns>
        public static string Between(string src, char start, char end)
        {
            string ret=String.Empty;
            int idxStart=src.IndexOf(start);
            if (idxStart != -1)
            {
                ++idxStart;
                int idxEnd=src.IndexOf(end, idxStart);
                if (idxEnd != -1)
                {
                    ret=src.Substring(idxStart, idxEnd-idxStart);
                }
            }
            return ret;
        }

        /// <summary>
        /// Returns the number of occurances of "find".
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <param name="find">The search char.</param>
        /// <returns>The # of times the char occurs in the search string.</returns>
        public static int Count(string src, char find)
        {
            int ret=0;
            foreach(char s in src)
            {
                if (s==find)
                {
                    ++ret;
                }
            }
            return ret;
        }

        /// <summary>
        /// Returns the rightmost char in src.
        /// </summary>
        /// <param name="src">The source string.</param>
        /// <returns>The rightmost char, or '\0' if the source has zero length.</returns>
        public static char Rightmost(string src)
        {
            char c='\0';
            if (src.Length>0)
            {
                c=src[src.Length-1];
            }
            return c;
        }
    }
}