Files
FlaxEngine/Source/Engine/Utilities/StringUtils.cs
Wojtek Figat 2acad9963f Fix #41
2020-12-23 10:14:51 +01:00

328 lines
11 KiB
C#

// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
namespace FlaxEngine
{
/// <summary>
/// String utilities class.
/// </summary>
public static class StringUtils
{
/// <summary>
/// Parse hexadecimals digit to value.
/// </summary>
/// <param name="c">The hex character.</param>
/// <returns>Value.</returns>
public static int HexDigit(char c)
{
int result;
if (c >= '0' && c <= '9')
{
result = c - '0';
}
else if (c >= 'a' && c <= 'f')
{
result = c + 10 - 'a';
}
else if (c >= 'A' && c <= 'F')
{
result = c + 10 - 'A';
}
else
{
result = 0;
}
return result;
}
/// <summary>
/// Removes extension from the file path.
/// </summary>
/// <param name="path">The path.</param>
/// <returns>Path without extension.</returns>
public static string GetPathWithoutExtension(string path)
{
int num = path.LastIndexOf('.');
if (num != -1)
{
return path.Substring(0, num);
}
return path;
}
/// <summary>
/// Normalizes the path to the standard Flax format (all separators are '/' except for drive 'C:\').
/// </summary>
/// <param name="path">The path.</param>
/// <returns>The normalized path.</returns>
public static string NormalizePath(string path)
{
if (string.IsNullOrEmpty(path))
return path;
var chars = path.ToCharArray();
// Convert all '\' to '/'
for (int i = 0; i < chars.Length; i++)
{
if (chars[i] == '\\')
chars[i] = '/';
}
// Fix case 'C:/' to 'C:\'
if (chars.Length > 2 && !char.IsDigit(chars[0]) && chars[1] == ':')
{
chars[2] = '\\';
}
return new string(chars);
}
/// <summary>
/// Normalizes the file extension to common format: no leading dot and all lowercase.
/// For example: '.TxT' will return 'txt'.
/// </summary>
/// <param name="extension">The extension.</param>
/// <returns>The normalized extension.</returns>
public static string NormalizeExtension(string extension)
{
if (extension.Length != 0 && extension[0] == '.')
extension = extension.Remove(0, 1);
return extension.ToLower();
}
/// <summary>
/// Combines the paths.
/// </summary>
/// <param name="left">The left.</param>
/// <param name="right">The right.</param>
/// <returns>The combined path</returns>
public static string CombinePaths(string left, string right)
{
int cnt = left.Length;
if (cnt > 1 && left[cnt - 1] != '/' && left[cnt - 1] != '\\'
&& (right.Length == 0 || (right[0] != '/' && right[0] != '\\')))
{
left += '/';
}
return left + right;
}
/// <summary>
/// Combines the paths.
/// </summary>
/// <param name="left">The left.</param>
/// <param name="middle">The middle.</param>
/// <param name="right">The right.</param>
/// <returns>The combined path</returns>
public static string CombinePaths(string left, string middle, string right)
{
return CombinePaths(CombinePaths(left, middle), right);
}
/// <summary>
/// Determines whether the specified path is relative or is absolute.
/// </summary>
/// <param name="path">The input path.</param>
/// <returns>
/// <c>true</c> if the specified path is relative; otherwise, <c>false</c> if is relative.
/// </returns>
public static bool IsRelative(string path)
{
bool isRooted = (path.Length >= 2 && char.IsLetterOrDigit(path[0]) && path[1] == ':') ||
path.StartsWith("\\\\") ||
path.StartsWith("/") ||
path.StartsWith("\\") ||
path.StartsWith("/");
return !isRooted;
}
/// <summary>
/// Converts path relative to the engine startup folder into absolute path.
/// </summary>
/// <param name="path">Path relative to the engine directory.</param>
/// <returns>Absolute path</returns>
public static string ConvertRelativePathToAbsolute(string path)
{
return ConvertRelativePathToAbsolute(Globals.StartupFolder, path);
}
/// <summary>
/// Converts path relative to basePath into absolute path.
/// </summary>
/// <param name="basePath">The base path.</param>
/// <param name="path">Path relative to basePath.</param>
/// <returns>Absolute path</returns>
public static string ConvertRelativePathToAbsolute(string basePath, string path)
{
string fullyPathed;
if (IsRelative(path))
{
fullyPathed = CombinePaths(basePath, path);
}
else
{
fullyPathed = path;
}
NormalizePath(fullyPathed);
return fullyPathed;
}
/// <summary>
/// Removes the relative parts from the path. For instance it replaces 'xx/yy/../zz' with 'xx/zz'.
/// </summary>
/// <param name="path">The input path.</param>
/// <returns>The output path.</returns>
public static string RemovePathRelativeParts(string path)
{
path = NormalizePath(path);
string[] components = path.Split('/');
Stack<string> stack = new Stack<string>();
foreach (var bit in components)
{
if (bit == "..")
{
if (stack.Count != 0)
{
var popped = stack.Pop();
if (popped == "..")
{
stack.Push(popped);
stack.Push(bit);
}
}
else
{
stack.Push(bit);
}
}
else if (bit == ".")
{
// Skip /./
}
else
{
stack.Push(bit);
}
}
bool isRooted = path.StartsWith("/");
string result = string.Join(Path.DirectorySeparatorChar.ToString(), stack.Reverse());
if (isRooted)
result = result.Insert(0, "/");
return result;
}
/// <summary>
/// Reverses the specified input string.
/// </summary>
/// <param name="s">The string to reverse.</param>
/// <returns>The reversed string.</returns>
public static string Reverse(this string s)
{
char[] charArray = s.ToCharArray();
Array.Reverse(charArray);
return new string(charArray);
}
private static readonly Regex IncNameRegex1 = new Regex("^(\\d+)");
private static readonly Regex IncNameRegex2 = new Regex("^\\)(\\d+)\\(");
/// <summary>
/// Tries to parse number in the name brackets at the end of the value and then increment it to create a new name.
/// Supports numbers at the end without brackets.
/// </summary>
/// <param name="name">The input name.</param>
/// <param name="isValid">Custom function to validate the created name.</param>
/// <returns>The new name.</returns>
public static string IncrementNameNumber(string name, Func<string, bool> isValid)
{
// Validate input name
if (isValid == null || isValid(name))
return name;
// Temporary data
int index;
int MaxChecks = 10000;
string result;
string reversed = name.Reverse();
// Find '<name><num>' case
var match = IncNameRegex1.Match(reversed);
if (match.Success && match.Groups.Count == 2)
{
// Get result
string num = match.Groups[0].Value.Reverse();
// Parse value
if (int.TryParse(num, out index))
{
// Get prefix
string prefix = name.Substring(0, name.Length - num.Length);
// Generate name
do
{
result = string.Format("{0}{1}", prefix, ++index);
if (MaxChecks-- < 0)
return name + Guid.NewGuid();
} while (!isValid(result));
if (result.Length > 0)
return result;
}
}
// Find '<name> (<num>)' case
match = IncNameRegex2.Match(reversed);
if (match.Success && match.Groups.Count == 2)
{
// Get result
string num = match.Groups[0].Value;
num = num.Substring(1, num.Length - 2).Reverse();
// Parse value
if (int.TryParse(num, out index))
{
// Get prefix
string prefix = name.Substring(0, name.Length - num.Length - 2);
// Generate name
do
{
result = string.Format("{0}({1})", prefix, ++index);
if (MaxChecks-- < 0)
return name + Guid.NewGuid();
} while (!isValid(result));
if (result.Length > 0)
return result;
}
}
// Generate name
index = 0;
do
{
result = string.Format("{0} {1}", name, index++);
if (MaxChecks-- < 0)
return name + Guid.NewGuid();
} while (!isValid(result));
return result;
}
}
}