Syntax highlighting

The last feature to implement is syntax highlighting.

New fields

Add a new field in the Buffer type:

// Pointer to the syntax definition
syndef: ?*const t.Syntax,

And one in the Row type:

/// True when the row has a multiline comment continuing into next line
ml_comment: bool,

This one becomes true when a line contains the leader that opens the multi-line comment, and stays true in all following rows, until the end of the block is found, in that row it becomes false again.

Fill the rest of Highlight enum

This is the full Highlight enum, with all needed highlight names:

/// All available highlight types.
pub const Highlight = enum(u8) {
    /// The normal highlight
    normal = 0,

    /// Line comments highlight
    comment,

    /// Multiline comments highlight
    mlcomment,

    /// Numbers highlight
    number,

    /// String highlight
    string,

    /// Highlight for keywords of type 'keyword'
    keyword,

    /// Highlight for keywords of type 'types'
    types,

    /// Highlight for keywords of type 'builtin'
    builtin,

    /// Highlight for keywords of type 'constant'
    constant,

    /// Highlight for keywords of type 'preproc'
    preproc,

    /// Highlight for uppercase words
    uppercase,

    /// Highlight for escape sequences in strings
    escape,

    /// Incremental search highlight
    incsearch,

    /// Highlight for non-printable characters
    nonprint,

    /// Highlight for error messages
    err,
};

Fill the rest of hlGroups array

This the full initializer of the hlGroups array, replace the previous one with it.

/// Array with highlight groups.
pub const hlGroups: [n_hl]t.HlGroup = arr: {
    // Initialize the hlGroups array at compile time. A []HlGroup array is
    // first declared undefined, then it is filled with all highlight groups.
    var hlg: [n_hl]t.HlGroup = undefined;
    hlg[int(.normal)] = .{
        .fg = FgColor.default,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.comment)] = .{
        .fg = FgColor.black_bright,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.mlcomment)] = .{
        .fg = FgColor.blue_bright,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.number)] = .{
        .fg = FgColor.white_bright,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.string)] = .{
        .fg = FgColor.green,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.keyword)] = .{
        .fg = FgColor.cyan,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.types)] = .{
        .fg = FgColor.cyan_bright,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.builtin)] = .{
        .fg = FgColor.magenta,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.constant)] = .{
        .fg = FgColor.yellow,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.preproc)] = .{
        .fg = FgColor.red_bright,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.uppercase)] = .{
        .fg = FgColor.yellow_bright,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.escape)] = .{
        .fg = FgColor.red,
        .bg = BgColor.default,
        .reverse = false,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.incsearch)] = .{
        .fg = FgColor.green,
        .bg = BgColor.default,
        .reverse = true,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.nonprint)] = .{
        .fg = FgColor.white,
        .bg = BgColor.default,
        .reverse = true,
        .bold = false,
        .italic = false,
        .underline = false,
    };
    hlg[int(.err)] = .{
        .fg = FgColor.red_bright,
        .bg = BgColor.default,
        .reverse = false,
        .bold = true,
        .italic = false,
        .underline = false,
    };
    break :arr hlg;
};