namespace Blog.Models;

/// <summary>
/// What a run of characters is, as far as a grayscale highlighter cares.
/// </summary>
/// <remarks>
/// Deliberately short. With no colour to spend, a line of code can carry about three distinctions
/// before they stop being distinctions: what the language says (<see cref="Keyword"/>), what the
/// program says (<see cref="String"/> and <see cref="Number"/>), and what the author says
/// (<see cref="Comment"/>). Everything else is <see cref="Text"/>.
/// </remarks>
public enum SyntaxKind
{
    /// <summary>Identifiers, operators, whitespace — anything with no treatment of its own.</summary>
    Text,

    Comment,

    /// <summary>A string, character or template literal, quotes included.</summary>
    String,

    Number,

    /// <summary>A word the language reserves, and in markup the tag brackets around a name.</summary>
    Keyword,

    /// <summary>
    /// The line that isn't code: a preprocessor directive, a shell variable, a doctype, a
    /// markdown heading, a JSON key.
    /// </summary>
    Meta
}

/// <summary>One run of characters from a line, and what it is.</summary>
public sealed record SyntaxToken(SyntaxKind Kind, string Text);