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Mojo function

once

def once[Emit: def() -> None & RegisterPassable & ImplicitlyCopyable, params: ContextParams, //](emit: Emit, ctx: Context[params])

CPU: runs emit unconditionally on the cooperative / tiled tiers (one worker per output), or gated on ctx._is_last_block on the split-axis tier (only the last-arriving worker emits).

emit is a value closure (its copy-captured state rides the value).

Parameters:

• ​Emit (def() -> None & RegisterPassable & ImplicitlyCopyable): The value-closure type of emit.
• ​params (ContextParams): Comptime dispatch parameters.

Args:

• ​emit (Emit): Callback to run.
• ​ctx (Context[params]): The dispatch bundle.