with-hash-table-iterator

(with-hash-table-iterator (name hash-table) body...)

Binds name to a LOCAL FUNCTION (an flet, not CL's macrolet) that answers one entry per call as (values t key value), and (values nil nil nil) once the table is exhausted. Because it is an ordinary local function it can also be passed as a value, which CL's macrolet binding cannot.

The table is SNAPSHOT on entry, so an entry added or removed during the walk is not seen -- CLHS leaves that case undefined. The order is unspecified.