hash-table—a hash table.
test—a function designator.
For the four standardized hash table test functions
(see make-hash-table
), the test value returned
is always a symbol. If an implementation permits additional
tests, it is implementation-dependent whether such tests are
returned as function objects or function names.
Returns the test used for comparing keys in hash-table.
Should signal an error of type type-error
if hash-table is not a hash table.