RaspberryIO_26/Swan.Tiny/Extensions.Strings.cs

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2019-12-09 17:25:54 +01:00
#nullable enable
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 => {
String x = m.ToString();
return x[0] + " " + x[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;
}
Type itemType = @this.GetType();
return itemType == typeof(String) ? @this as String ?? String.Empty : 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, Boolean 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 {
String jsonText = Json.Serialize(@this, false, "$type");
Object? 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, Int32 startIndex, Int32 endIndex) {
if(@this == null) {
return String.Empty;
}
Int32 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, Int32 startIndex, Int32 length) {
if(@this == null) {
return String.Empty;
}
Int32 start = startIndex.Clamp(0, @this.Length - 1);
Int32 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;
}
String 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 Boolean 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(),
Boolean 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, Int32 spaces = 4) {
if(value == null) {
value = String.Empty;
}
if(spaces <= 0) {
return value;
}
String[] lines = value.ToLines();
StringBuilder builder = new StringBuilder();
String indentStr = new String(' ', spaces);
foreach(String 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<Int32, Int32> TextPositionAt(this String value, Int32 charIndex) {
if(value == null) {
return Tuple.Create(0, 0);
}
Int32 index = charIndex.Clamp(0, value.Length - 1);
Int32 lineIndex = 0;
Int32 colNumber = 0;
for(Int32 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 Int64 bytes) => ((UInt64)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 UInt64 bytes) {
Int32 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, Int32 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, Int32 maximumLength, String omission) => value == null ? null : 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 Boolean Contains(this String value, params Char[] chars) => chars?.Length == 0 || !String.IsNullOrEmpty(value) && chars != null && 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 Int32 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;
}
}