Comprehensive Jai programming language reference and cheat sheet. Use when working with Jai code, tree-sitter-jai grammar development, or answering questions about Jai syntax and semantics. Covers declarations, types, control flow, directives, metaprogramming, and all language features. Trigger: user mentions 'Jai', 'Jai language', 'tree-sitter-jai', or asks about Jai syntax.
Design around contracts, not implementations. Use when: (1) building multi-step features where placeholders would otherwise accumulate, (2) expensive or stateful objects need mock and real implementations (databases, caches, external services), (3) scaling fault lines exist where in-proc vs. remote implementations should be swappable, (4) test mocks need to verify behavior through observation hooks, (5) designing a system that may need to scale from single-process to distributed without a rewrite, (6) the user mentions 'interface first', 'mock implementation', 'store interface', 'transaction boundary', 'scaling fault line', 'single binary', 'deployment topology', or 'test contract'. Primarily Go, but applicable to any language with interface-like constructs (Rust traits, Java/Scala interfaces).
Apply the actor pattern for thread-safe state management. Use when: (1) multiple threads/goroutines need shared mutable state, (2) replacing mutex-locked structs or atomic patterns, (3) building a service layer that owns in-memory state plus persistence, (4) application has distinct operational modes (setup, running, error) requiring a coordinator that manages sub-actors, (5) the user mentions 'actor pattern', 'goroutine event loop', 'channel-based state management', or 'actors managing actors'. Supports Go, Jai, C, Rust, Odin, and Zig.
Comprehensive tree-sitter grammar development guide covering the JavaScript DSL, precedence systems, conflict resolution, external scanners, state explosion mitigation, and best practices distilled from studying 17 reference grammars and the official documentation. Use when building or modifying tree-sitter grammars, debugging parse errors, optimizing parser generation, or understanding tree-sitter internals. Trigger: user mentions 'tree-sitter', 'grammar.js', 'parser generation', 'tree-sitter conflicts', 'external scanner', 'state explosion', or asks about tree-sitter grammar development.
Comprehensive guide for building Emacs tree-sitter major modes. Covers the full treesit.el API, font-lock rules, indentation, navigation, imenu, and best practices distilled from studying 17+ production modes. Use when creating or modifying an Emacs tree-sitter mode (*-ts-mode), working with treesit-font-lock-rules, treesit-simple-indent-rules, or any Emacs tree-sitter integration. Trigger: user mentions 'ts-mode', 'tree-sitter mode', 'treesit', 'font-lock-rules', 'indent-rules', or asks about Emacs tree-sitter major mode development.
Extract subsystem-specific config structs from a monolithic/global configuration using the strangler fig pattern. Each subsystem gets a focused config struct and a pure conversion function, breaking the dependency on the global config package. Use when: (1) multiple packages import a central config struct and cherry-pick fields, (2) you want to decouple a subsystem so it no longer imports the config package, (3) config has cross-referencing lookups (e.g. account name → key) that should be pre-resolved, (4) the user mentions 'extract config', 'decouple config', 'config refactor', or 'strangler fig config'.
Scaffold a new Go web application with single-binary architecture, templ HTML templates, htmx interactivity, chi router, vendored frontend assets, embedded static files, TOML config with reflection-based gen-config, and a central build.sh script. Use when the user wants to create a new Go web project, HTTP API, dashboard, or web application from scratch. Trigger phrases: 'new Go project', 'scaffold', 'start a new web app', 'create a Go web server'.