case

(case key ((datum...) expression...)... [(else expression...)])

Evaluates key and takes the first clause one of whose datums is eqv? to it, answering the value of its last expression. An else clause matches anything. A clause may be ((datum...) => receiver) or (else => receiver), which calls receiver with the key. When no clause is taken the value is unspecified. A string datum matches only that same string object, so a computed key never matches it (see eqv?).