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XenoAtom.Ansi

XenoAtom.Ansi is the low-level ANSI/VT library that powers markup and styling in XenoAtom.Terminal and XenoAtom.Terminal.UI.

It provides:

  • ANSI/VT sequence emission (SGR styles, some cursor/screen operations)
  • Lightweight markup rendering (Rich/Spectre.Console-like tags)
  • ANSI parsing/tokenization and styled runs
  • ANSI-aware text utilities (strip/measure/wrap/truncate)

Markup

Terminal.UI uses XenoAtom.Ansi markup syntax in multiple places:

  • the Markup control
  • prompt help strings (for example HelpMarkup(...))
  • internal markup parsing utilities (MarkupTextParser)

Example:

new Markup("[bold yellow]Warning:[/] disk is almost full");

Markup is designed to be safe with interpolated values: user input is escaped so it cannot inject tags when you use the interpolated handler APIs. When you build markup manually, you can escape with:

using XenoAtom.Ansi;

var safe = AnsiMarkup.Escape(userInput);

See:

  • Markup (syntax reference and Terminal.UI semantic tokens)

How Terminal.UI uses markup

Terminal.UI does not render "raw ANSI". It parses markup into:

  • plain text
  • a list of styled runs (StyledRun[]) that reference Terminal.UI.Style

These runs are then rendered into a CellBuffer.

ANSI emission (AnsiWriter)

If you are using XenoAtom.Terminal directly (without Terminal.UI), XenoAtom.Ansi provides AnsiWriter for producing escape sequences efficiently:

using XenoAtom.Ansi;

using var b = new AnsiBuilder();
var w = new AnsiWriter(b);
w.Foreground(AnsiColors.BrightYellow).Decorate(AnsiDecorations.Bold).Write("Warning").ResetStyle();

Terminal.UI renders a CellBuffer and then writes ANSI via the host. AnsiWriter is most useful when you are building a CLI/TUI directly on XenoAtom.Terminal.

Relationship to Terminal and Terminal.UI

  • XenoAtom.Terminal uses XenoAtom.Ansi for styles, markup, and output helpers.
  • XenoAtom.Terminal.UI uses XenoAtom.Ansi for markup parsing and styled runs, and then renders to a CellBuffer.

See: