version: "1.0.1" name: patterns/context-struct description: Context Struct Pattern (C-Specific) pattern for C development

Context Struct Pattern (C-Specific)

Pass state explicitly as struct pointer parameter rather than using globals. First parameter to functions is context containing state and dependencies.

ikigai Application

Core pattern: Every module uses this:

• ik_repl_ctx_t - REPL state
• ik_term_ctx_t - Terminal state
• ik_scrollback_t - Scrollback state
• ik_env_t - Runtime environment (planned)

Convention: Context is first parameter after talloc context:

res_t ik_scrollback_append(ik_scrollback_t *ctx, const char *line);

Benefits:

• No global state
• Multiple instances possible
• Explicit dependencies
• Testable (inject mock contexts)

See: project/explicit_context.md for ik_env_t design.