Untie Documentation

These docs describe the public API at library version 0.2.1 and layout revision 1. They focus on the behavior a host or code assistant can rely on when integrating Untie; they are not a TeX or Typst language tutorial.

Start Here

• Getting started shows the complete LoadMathFont -> NewRenderer -> Render -> draw flow, with the lower-level engine path documented separately.
• Core concepts and ownership explains the pipeline, the lifetime of each value, and the inline/display boundary.
• Rendering the display list defines coordinates, items, lines, tags, hits, overflow, bounds, drawing helpers, and optional SVG/PNG output.

Integration Guides

• MyGo integration provides the bounded adapter for MyGo Markdown math, direct UI elements, theme-role drawing, and existing-box drawing.
• Fonts and fallback covers the required math face, optional text face, ordered fallbacks, face IDs, and font identity.
• Parsing, diagnostics, and recovery covers TeX and Typst input, source ranges, diagnostics, links, and recoverable output.
• Errors and resource limits describes fatal layout errors, parse-time recovery, and configurable limits.
• Canonical IR and Engine.LayoutFormulaContext is for hosts that inspect or cache the language-neutral formula tree.
• Concurrency, lifecycle, and caching describes safe reuse, cancellation, package-level caching, and ownership under concurrency.
• Accessibility text explains Alt.Text, Alt.Speech, fallback markers, and how accessibility errors differ from layout errors.

Compatibility and Verification

• Supported TeX summarizes the tested TeX math subset and its explicit exclusions.
• Supported Typst summarizes the restricted Typst math frontend and its explicit exclusions.
• API stability tiers separates the host API, advanced IR types, and diagnostic serialization.
• Release process records versioning, module tags, and the automated GitHub release gate.
• Security policy explains supported versions and private vulnerability reporting.
• Compatibility and verification summarizes the tracked corpora and reviewed coverage.
• Performance explains the benchmark workload, cache strategies, and allocation metrics.
• Migrating to 0.2 maps the removed low-level font and drawing conveniences to the current host facade, render helpers, and output adapters.
• encode/svg emits deterministic standalone SVG through the same framework-neutral drawing protocol.
• encode/raster renders a display box to a deterministic antialiased RGBA image or PNG without cgo or a UI dependency.

Recommended Reading Paths

For a normal application:

1. Getting started
2. Rendering the display list
3. Fonts and fallback
4. Errors and resource limits

For an editor or document application:

1. Parsing, diagnostics, and recovery
2. Concurrency, lifecycle, and caching
3. Accessibility text
4. The supported-syntax page for the active input dialect

For a host that stores or transforms formula trees:

1. Canonical IR
2. API stability tiers
3. Compatibility and verification
4. Performance

Scope

Untie does not provide a document engine, font discovery, system keyboard layout, DOM, network access, or semantic TeX/Typst execution. The host owns those concerns. Untie's contract ends at a validated Box, its accessibility text, and its source metadata.

The bundled examples/mygo application demonstrates direct formula elements in a native editor.

For MyGo integration, use contrib/mygo. It can render a formula directly as a ui.Element, bind Markdown math, or draw an existing Untie box.