Chain of Responsibility Pattern
Pass request along a chain of handlers until one handles it. Each handler decides to process or pass to next. In C, linked list of handler functions.
ikigai Application
Input processing: Bytes flow through: escape sequence detector → UTF-8 assembler → action mapper → REPL handler.
Command dispatch: Try slash command handlers in order until one matches.
Future uses:
- Middleware for tool execution (auth, logging, rate limiting)
- Message preprocessing pipeline
- Error recovery chain
Implementation:
typedef res_t (*handler_fn)(void *ctx, request_t *req, handler_fn next);
Benefit: Add/remove processing steps without modifying existing handlers.