go

(go tag)

Transfers control to the given go tag of the (dynamically) enclosing tagbody; the forms after the jump point continue executing. It is an error when no enclosing tagbody has the tag.

On the JVM and WASM compilers go is lexical: it must target a tag of a tagbody that lexically encloses it (the interpreter additionally supports dynamic go across function-call boundaries, i.e. a tag established by the caller). A tag reached from inside a nested lambda -- what a handler-bind handler that resumes its loop with a go produces -- is lowered to a non-local exit that re-enters the tagbody at the tag, so it works on every backend; such a program compiles in exception-handling mode, so the wasm runs need wasmtime -W exceptions=y.