Rune Struct

Summary

Represents a Unicode scalar value.

Description

A Rune is a Unicode scalar value, which is a numerical value assigned to every character in the Unicode standard. This struct provides a way to work with individual Unicode code points in a safe and efficient manner. It is particularly useful when dealing with strings that may contain multi-byte characters or surrogate pairs.

The Rune struct implements the IComparable, IComparable<T>, IEquatable<T>, and ISpanFormattable interfaces, allowing for comparisons, equality checks, and formatting within spans.

Fields

• readonly System.Text.Rune Null
  Represents the null rune, which is equivalent to the Unicode replacement character (U+FFFD).

Constructors

• Rune(char c)
  Initializes a new instance of the Rune struct by using the specified character.
  Parameters

  • c: The character to represent as a rune.

  Exceptions

  • ArgumentException: If the specified character is not a valid Unicode scalar value (i.e., it's a surrogate code unit).
• Rune(uint codePoint)
  Initializes a new instance of the Rune struct by using the specified Unicode code point.
  Parameters

  • codePoint: The Unicode code point to represent as a rune.

  Exceptions

  • ArgumentException: If the specified code point is not a valid Unicode scalar value.

Methods

• int CompareTo(System.Text.Rune other)
  Compares the current rune with another rune.
• int CompareTo(object? obj)
  Compares the current rune with another object.
• bool Equals(System.Text.Rune other)
  Indicates whether the current rune is equal to another rune.
• bool Equals(object? obj)
  Indicates whether the current rune is equal to another object.
• int GetHashCode()
  Returns the hash code for the current rune.
• string ToString()
  Converts the current rune to its string representation.
• bool TryGetCodePoint(out uint codePoint)
  Attempts to get the Unicode code point of the current rune.
• bool IsControl()
  Indicates whether the current rune is a control character.
• bool IsDigit()
  Indicates whether the current rune is a digit character.
• bool IsLetter()
  Indicates whether the current rune is a letter character.
• bool IsLowSurrogate()
  Indicates whether the current rune is a low surrogate code unit.
• bool IsHighSurrogate()
  Indicates whether the current rune is a high surrogate code unit.
• bool IsSurrogate()
  Indicates whether the current rune is a surrogate code unit.
• bool IsSymbol()
  Indicates whether the current rune is a symbol character.
• bool IsPunctuation()
  Indicates whether the current rune is a punctuation character.
• bool IsWhiteSpace()
  Indicates whether the current rune is a whitespace character.

Operators

• bool operator ==(System.Text.Rune left, System.Text.Rune right)
  Compares two runes for equality.
• bool operator !=(System.Text.Rune left, System.Text.Rune right)
  Compares two runes for inequality.
• int operator <(System.Text.Rune left, System.Text.Rune right)
  Compares two runes for less than.
• int operator >(System.Text.Rune left, System.Text.Rune right)
  Compares two runes for greater than.
• int operator <=(System.Text.Rune left, System.Text.Rune right)
  Compares two runes for less than or equal to.
• int operator >=(System.Text.Rune left, System.Text.Rune right)
  Compares two runes for greater than or equal to.

Example

using System;

public class RuneExample
{
    public static void Main(string[] args)
    {
        // Create a Rune from a character
        Rune apostrophe = new Rune('\'');
        Console.WriteLine($"Rune for apostrophe: {apostrophe}"); // Output: Rune for apostrophe: '

        // Create a Rune from a code point
        // Unicode code point for 'A' is U+0041
        Rune capitalA = new Rune(0x0041);
        Console.WriteLine($"Rune for U+0041: {capitalA}"); // Output: Rune for U+0041: A

        // Check if a rune is a digit
        Rune digitFive = new Rune('5');
        if (digitFive.IsDigit())
        {
            Console.WriteLine("'5' is a digit."); // Output: '5' is a digit.
        }

        // Get the code point of a rune
        if (apostrophe.TryGetCodePoint(out uint codePoint))
        {
            Console.WriteLine($"The code point for '{apostrophe}' is U+{codePoint:X4}"); // Output: The code point for ''' is U+0027
        }

        // Compare runes
        Rune b = new Rune('b');
        if (b > apostrophe)
        {
            Console.WriteLine("'b' comes after '."); // Output: 'b' comes after '.
        }
    }
}