The TJS Language

Why TJS exists, the principles it will not bend, its declarations and syntax, and the design notes behind the harder decisions — the reference half of the language, where the TJS section is the practical half.

• Why TJS
• Design Principles & Invariants
• Declarations
• TJS Syntax Reference
• Dictionary Defaults (Merge-on-Partial Object Arguments)
• Type identity: who answers "does this value satisfy this type?"
• Runtime fusion: what may be shared between TJS modules, and what may not
• North star: JSON-Schema + predicates as the single source of truth for types
• FunctionPredicate: Design Notes
• Case study: fixing switch
• Small scoped parsers, not a rewrite
• Ambient Contracts — probe reality, derive verified predicate contracts
• Native Engine Integration: TJS in V8 or JavaScriptCore
• tjs-lang Technical Context