ADR 54: Streaming iterator uses direct function calls

Date: 2026-07-02

Context

ADR 50 specified a streaming return where the iterator type's :next and :deinit methods are called via Zig dot syntax (self.next()). The initial implementation generated __self.counter_next(), but Zig 0.16 requires functions to be in the struct's declaration scope for dot syntax, and top-level functions are not found there.

Decision

The generated __next and __free shims call the iterator functions directly: counter_next(__self) instead of __self.counter_next(). The :clj-zig/iter metadata names free functions whose first parameter is *IterType, not struct methods. The init fn wraps the body in an inner impl fn that returns *IterType, then converts to usize with @intFromPtr.

Consequences

The iterator functions are plain top-level functions, not struct methods. They are declared via defz or inline in the body. The generated shims are agnostic to where the functions live, as long as they are in scope.