RaspberryIO_26/Swan.Lite/Extensions.Strings.cs

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C#
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2019-12-04 18:57:18 +01:00
using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using Swan.Formatters;
namespace Swan
{
/// <summary>
/// String related extension methods.
/// </summary>
public static class StringExtensions
{
#region Private Declarations
private const RegexOptions StandardRegexOptions =
RegexOptions.Multiline | RegexOptions.Compiled | RegexOptions.CultureInvariant;
private static readonly string[] ByteSuffixes = { "B", "KB", "MB", "GB", "TB" };
private static readonly Lazy<Regex> SplitLinesRegex =
new Lazy<Regex>(() => new Regex("\r\n|\r|\n", StandardRegexOptions));
private static readonly Lazy<Regex> UnderscoreRegex =
new Lazy<Regex>(() => new Regex(@"_", StandardRegexOptions));
private static readonly Lazy<Regex> CamelCaseRegEx =
new Lazy<Regex>(() => new Regex(@"[a-z][A-Z]", StandardRegexOptions));
private static readonly Lazy<MatchEvaluator> SplitCamelCaseString = new Lazy<MatchEvaluator>(() => m =>
{
var x = m.ToString();
return x[0] + " " + x.Substring(1, x.Length - 1);
});
private static readonly Lazy<string[]> InvalidFilenameChars =
new Lazy<string[]>(() => Path.GetInvalidFileNameChars().Select(c => c.ToString()).ToArray());
#endregion
/// <summary>
/// Returns a string that represents the given item
/// It tries to use InvariantCulture if the ToString(IFormatProvider)
/// overload exists.
/// </summary>
/// <param name="this">The item.</param>
/// <returns>A <see cref="string" /> that represents the current object.</returns>
public static string ToStringInvariant(this object? @this)
{
if (@this == null)
return string.Empty;
var itemType = @this.GetType();
if (itemType == typeof(string))
return @this as string ?? string.Empty;
return Definitions.BasicTypesInfo.Value.ContainsKey(itemType)
? Definitions.BasicTypesInfo.Value[itemType].ToStringInvariant(@this)
: @this.ToString();
}
/// <summary>
/// Returns a string that represents the given item
/// It tries to use InvariantCulture if the ToString(IFormatProvider)
/// overload exists.
/// </summary>
/// <typeparam name="T">The type to get the string.</typeparam>
/// <param name="item">The item.</param>
/// <returns>A <see cref="string" /> that represents the current object.</returns>
public static string ToStringInvariant<T>(this T item)
=> typeof(string) == typeof(T) ? item as string ?? string.Empty : ToStringInvariant(item as object);
/// <summary>
/// Removes the control characters from a string except for those specified.
/// </summary>
/// <param name="value">The input.</param>
/// <param name="excludeChars">When specified, these characters will not be removed.</param>
/// <returns>
/// A string that represents the current object.
/// </returns>
/// <exception cref="ArgumentNullException">input.</exception>
public static string RemoveControlCharsExcept(this string value, params char[] excludeChars)
{
if (value == null)
throw new ArgumentNullException(nameof(value));
if (excludeChars == null)
excludeChars = Array.Empty<char>();
return new string(value
.Where(c => char.IsControl(c) == false || excludeChars.Contains(c))
.ToArray());
}
/// <summary>
/// Removes all control characters from a string, including new line sequences.
/// </summary>
/// <param name="value">The input.</param>
/// <returns>A <see cref="string" /> that represents the current object.</returns>
/// <exception cref="ArgumentNullException">input.</exception>
public static string RemoveControlChars(this string value) => value.RemoveControlCharsExcept(null);
/// <summary>
/// Outputs JSON string representing this object.
/// </summary>
/// <param name="this">The object.</param>
/// <param name="format">if set to <c>true</c> format the output.</param>
/// <returns>A <see cref="string" /> that represents the current object.</returns>
public static string ToJson(this object @this, bool format = true) =>
@this == null ? string.Empty : Json.Serialize(@this, format);
/// <summary>
/// Returns text representing the properties of the specified object in a human-readable format.
/// While this method is fairly expensive computationally speaking, it provides an easy way to
/// examine objects.
/// </summary>
/// <param name="this">The object.</param>
/// <returns>A <see cref="string" /> that represents the current object.</returns>
public static string Stringify(this object @this)
{
if (@this == null)
return "(null)";
try
{
var jsonText = Json.Serialize(@this, false, "$type");
var jsonData = Json.Deserialize(jsonText);
return new HumanizeJson(jsonData, 0).GetResult();
}
catch
{
return @this.ToStringInvariant();
}
}
/// <summary>
/// Retrieves a section of the string, inclusive of both, the start and end indexes.
/// This behavior is unlike JavaScript's Slice behavior where the end index is non-inclusive
/// If the string is null it returns an empty string.
/// </summary>
/// <param name="this">The string.</param>
/// <param name="startIndex">The start index.</param>
/// <param name="endIndex">The end index.</param>
/// <returns>Retrieves a substring from this instance.</returns>
public static string Slice(this string @this, int startIndex, int endIndex)
{
if (@this == null)
return string.Empty;
var end = endIndex.Clamp(startIndex, @this.Length - 1);
return startIndex >= end ? string.Empty : @this.Substring(startIndex, (end - startIndex) + 1);
}
/// <summary>
/// Gets a part of the string clamping the length and startIndex parameters to safe values.
/// If the string is null it returns an empty string. This is basically just a safe version
/// of string.Substring.
/// </summary>
/// <param name="this">The string.</param>
/// <param name="startIndex">The start index.</param>
/// <param name="length">The length.</param>
/// <returns>Retrieves a substring from this instance.</returns>
public static string SliceLength(this string @this, int startIndex, int length)
{
if (@this == null)
return string.Empty;
var start = startIndex.Clamp(0, @this.Length - 1);
var len = length.Clamp(0, @this.Length - start);
return len == 0 ? string.Empty : @this.Substring(start, len);
}
/// <summary>
/// Splits the specified text into r, n or rn separated lines.
/// </summary>
/// <param name="this">The text.</param>
/// <returns>
/// An array whose elements contain the substrings from this instance
/// that are delimited by one or more characters in separator.
/// </returns>
public static string[] ToLines(this string @this) =>
@this == null ? Array.Empty<string>() : SplitLinesRegex.Value.Split(@this);
/// <summary>
/// Humanizes (make more human-readable) an identifier-style string
/// in either camel case or snake case. For example, CamelCase will be converted to
/// Camel Case and Snake_Case will be converted to Snake Case.
/// </summary>
/// <param name="value">The identifier-style string.</param>
/// <returns>A <see cref="string" /> humanized.</returns>
public static string Humanize(this string value)
{
if (value == null)
return string.Empty;
var returnValue = UnderscoreRegex.Value.Replace(value, " ");
returnValue = CamelCaseRegEx.Value.Replace(returnValue, SplitCamelCaseString.Value);
return returnValue;
}
/// <summary>
/// Humanizes (make more human-readable) an boolean.
/// </summary>
/// <param name="value">if set to <c>true</c> [value].</param>
/// <returns>A <see cref="string" /> that represents the current boolean.</returns>
public static string Humanize(this bool value) => value ? "Yes" : "No";
/// <summary>
/// Humanizes (make more human-readable) the specified value.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>A <see cref="string" /> that represents the current object.</returns>
public static string Humanize(this object value) =>
value switch
{
string stringValue => stringValue.Humanize(),
bool boolValue => boolValue.Humanize(),
_ => value.Stringify()
};
/// <summary>
/// Indents the specified multi-line text with the given amount of leading spaces
/// per line.
/// </summary>
/// <param name="value">The text.</param>
/// <param name="spaces">The spaces.</param>
/// <returns>A <see cref="string" /> that represents the current object.</returns>
public static string Indent(this string value, int spaces = 4)
{
if (value == null) value = string.Empty;
if (spaces <= 0) return value;
var lines = value.ToLines();
var builder = new StringBuilder();
var indentStr = new string(' ', spaces);
foreach (var line in lines)
{
builder.AppendLine($"{indentStr}{line}");
}
return builder.ToString().TrimEnd();
}
/// <summary>
/// Gets the line and column number (i.e. not index) of the
/// specified character index. Useful to locate text in a multi-line
/// string the same way a text editor does.
/// Please not that the tuple contains first the line number and then the
/// column number.
/// </summary>
/// <param name="value">The string.</param>
/// <param name="charIndex">Index of the character.</param>
/// <returns>A 2-tuple whose value is (item1, item2).</returns>
public static Tuple<int, int> TextPositionAt(this string value, int charIndex)
{
if (value == null)
return Tuple.Create(0, 0);
var index = charIndex.Clamp(0, value.Length - 1);
var lineIndex = 0;
var colNumber = 0;
for (var i = 0; i <= index; i++)
{
if (value[i] == '\n')
{
lineIndex++;
colNumber = 0;
continue;
}
if (value[i] != '\r')
colNumber++;
}
return Tuple.Create(lineIndex + 1, colNumber);
}
/// <summary>
/// Makes the file name system safe.
/// </summary>
/// <param name="value">The s.</param>
/// <returns>
/// A string with a safe file name.
/// </returns>
/// <exception cref="ArgumentNullException">s.</exception>
public static string ToSafeFilename(this string value) =>
value == null
? throw new ArgumentNullException(nameof(value))
: InvalidFilenameChars.Value
.Aggregate(value, (current, c) => current.Replace(c, string.Empty))
.Slice(0, 220);
/// <summary>
/// Formats a long into the closest bytes string.
/// </summary>
/// <param name="bytes">The bytes length.</param>
/// <returns>
/// The string representation of the current Byte object, formatted as specified by the format parameter.
/// </returns>
public static string FormatBytes(this long bytes) => ((ulong)bytes).FormatBytes();
/// <summary>
/// Formats a long into the closest bytes string.
/// </summary>
/// <param name="bytes">The bytes length.</param>
/// <returns>
/// A copy of format in which the format items have been replaced by the string
/// representations of the corresponding arguments.
/// </returns>
public static string FormatBytes(this ulong bytes)
{
int i;
double dblSByte = bytes;
for (i = 0; i < ByteSuffixes.Length && bytes >= 1024; i++, bytes /= 1024)
{
dblSByte = bytes / 1024.0;
}
return $"{dblSByte:0.##} {ByteSuffixes[i]}";
}
/// <summary>
/// Truncates the specified value.
/// </summary>
/// <param name="value">The value.</param>
/// <param name="maximumLength">The maximum length.</param>
/// <returns>
/// Retrieves a substring from this instance.
/// The substring starts at a specified character position and has a specified length.
/// </returns>
public static string? Truncate(this string value, int maximumLength) =>
Truncate(value, maximumLength, string.Empty);
/// <summary>
/// Truncates the specified value and append the omission last.
/// </summary>
/// <param name="value">The value.</param>
/// <param name="maximumLength">The maximum length.</param>
/// <param name="omission">The omission.</param>
/// <returns>
/// Retrieves a substring from this instance.
/// The substring starts at a specified character position and has a specified length.
/// </returns>
public static string? Truncate(this string value, int maximumLength, string omission)
{
if (value == null)
return null;
return value.Length > maximumLength
? value.Substring(0, maximumLength) + (omission ?? string.Empty)
: value;
}
/// <summary>
/// Determines whether the specified <see cref="string"/> contains any of characters in
/// the specified array of <see cref="char"/>.
/// </summary>
/// <returns>
/// <c>true</c> if <paramref name="value"/> contains any of <paramref name="chars"/>;
/// otherwise, <c>false</c>.
/// </returns>
/// <param name="value">
/// A <see cref="string"/> to test.
/// </param>
/// <param name="chars">
/// An array of <see cref="char"/> that contains characters to find.
/// </param>
public static bool Contains(this string value, params char[] chars) =>
chars?.Length == 0 || (!string.IsNullOrEmpty(value) && value.IndexOfAny(chars) > -1);
/// <summary>
/// Replaces all chars in a string.
/// </summary>
/// <param name="value">The value.</param>
/// <param name="replaceValue">The replace value.</param>
/// <param name="chars">The chars.</param>
/// <returns>The string with the characters replaced.</returns>
public static string ReplaceAll(this string value, string replaceValue, params char[] chars) =>
chars.Aggregate(value, (current, c) => current.Replace(new string(new[] { c }), replaceValue));
/// <summary>
/// Convert hex character to an integer. Return -1 if char is something
/// other than a hex char.
/// </summary>
/// <param name="value">The c.</param>
/// <returns>Converted integer.</returns>
public static int Hex2Int(this char value) =>
value >= '0' && value <= '9'
? value - '0'
: value >= 'A' && value <= 'F'
? value - 'A' + 10
: value >= 'a' && value <= 'f'
? value - 'a' + 10
: -1;
}
}