protocol

protocol

Data types that cross the MoonBit-to-JavaScript boundary: the view tree, diff patches, user intents, and diagnostics. Everything defined here is serializable to JSON and has no dependency on the CRDT internals.

This package is the stable contract between the MoonBit engine and the TypeScript/React frontend. It also contains the two conversion functions that build a ViewNode tree from a ProjNode tree or a pretty-printer Layout.

Public API

• ViewNode — tree node sent to the frontend; carries id, kind_tag, label, text, text_range, token_spans, and children
• ViewPatch — incremental update: TextChange, ReplaceNode, InsertChild, RemoveChild, UpdateNode, SetDecorations, SetDiagnostics, SetSelection, SelectNode, FullTree
• UserIntent — frontend-originated action: TextEdit, StructuralEdit, SelectNode, SetCursor, Undo, Redo, CommitEdit
• Decoration / Diagnostic / Severity — CodeMirror decoration and lint annotations
• proj_to_view_node — converts a ProjNode[T] + SourceMap into a ViewNode
• layout_to_view_tree — converts a pretty-printer Layout into a ViewNode tree

Consumers

• editor — produces ViewPatch sequences via compute_view_patches and compute_pretty_patches
• lang/lambda/companion — passes ViewAnnotation arrays into proj_to_view_node
• ffi/lambda, ffi/json, ffi/markdown — serialize ViewPatch / ViewNode to JSON for JavaScript
• Root moon.pkg (canopy module facade)

Dependencies

• dowdiness/canopy/core — NodeId, ProjNode, SourceMap
• dowdiness/pretty — Layout, SyntaxCategory
• moonbitlang/core/json — ToJson / FromJson derivations

Stability

Stable wire format / public surface — changes here break the TypeScript frontend and require coordinated updates to the JS consumer side.

Notes

UserIntent implements both ToJson and FromJson — it is the one type that flows both directions across the FFI boundary. All other protocol types are output-only (MoonBit → JS).