rontolisp:then*

(rontolisp:then* future &rest functions)

Variadic chain sugar for rontolisp:then: threads the value through each function in order without the parenthesis nesting a manual chain would require. Each function receives the previous stage's (auto-flattened via await) settled value; a stage returning a future is flattened on the next stage's read. With no callbacks the operator returns the input future unchanged (documented degenerate identity).

A non-future first argument is a type-error.

Note on the name: this is then + * (the CL convention for a variadic sibling of a two-argument operator), not thenCompose/thenApply from Java's CompletableFuture; because await flattens on read, the "compose" and "apply" distinctions collapse into the same shape here.

Backend support

Same as rontolisp:then: interpreter, JVM, WASM --component, and the success-only shape on Preview 1 WASM. --no-gc rejects at compile time.