cl-case is an autoloaded Lisp macro in `cl-macs.el'.

(cl-case EXPR (KEYLIST BODY...)...)

Eval EXPR and choose among clauses on that value.
Each clause looks like (KEYLIST BODY...). EXPR is evaluated and compared
against each key in each KEYLIST; the corresponding BODY is evaluated.
If no clause succeeds, cl-case returns nil. A single atom may be used in
place of a KEYLIST of one atom. A KEYLIST of t or `otherwise' is
allowed only in the final clause, and matches if no other keys match.
Key values are compared by `eql'.