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name: patterns/chain-of-responsibility description: Chain of Responsibility Pattern pattern for C development

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:

Copytypedef res_t (*handler_fn)(void *ctx, request_t *req, handler_fn next);

Benefit: Add/remove processing steps without modifying existing handlers.