zetl

Xanadu View Design

Status: Accepted

Context

zetl needed a focused reading mode that shows connections between notes. The design question was how to render Ted Nelson’s Xanadu concept of “parallel pages with visible connections” in a terminal.

See Xanadu Lineage for the conceptual background and SPEC-009 Xanadu View for the full specification.

Key decisions

ADR-016: Use ratatui + crossterm

The TUI framework was already in use for zetl tui. Reusing it for zetl view provides consistent behavior across terminal emulators and avoids a second rendering dependency.

ADR-017: Color-paired anchor numbers

Each wikilink gets a numbered anchor glyph [N] in the main pane. The corresponding context card in the right pane shares the same color. A bridge column between the panes draws connectors linking each anchor to its card.

This is more practical in a terminal than literal connecting lines (which would require pixel-level rendering). The color pairing provides the visual association that Xanadu’s bridge connectors achieve.

ADR-018: Override SPEC-001 TUI scope exclusion

SPEC-001 originally scoped out TUI functionality. The value of a Xanadu-style reader justified overriding this exclusion. The view command adds significant user value for knowledge exploration.

Terminal compatibility

The view supports three rendering modes:

  • True-color — full RGB color pairing for modern terminals
  • 8-color — mapped to the 8 basic ANSI colors
  • No-color — plain text with numbered anchors only

Narrow terminals (<60 cols) fall back to a single-pane layout.

See also: View Command, Xanadu Lineage, TUI

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