rontolisp:streamp

(rontolisp:streamp value)

Returns t if value is an asynchronous stream — as returned by rontolisp:make-stream or found in a rontolisp:fetch response body — and nil otherwise.

This is a different symbol from cl:streamp, the file-stream predicate: each answers nil for the other's streams.

An asynchronous stream is an opaque value: it has no reader syntax and prints as #<STREAM>.

Backend support

Asynchronous streams exist on the interpreter, the JVM backend and -- for the request/response body streams rontolisp:fetch / rontolisp:http-handler produce -- the --component WASM backend. A Preview 1 WASM module can hold a stream value only when a host-backed body gives it one; where none can exist, rontolisp:streamp answers nil and rontolisp:stream-read / rontolisp:stream-close signal an error when called.