when-let* (bindings &body forms)

Creates new variable bindings, and conditionally executes forms.

bindings must be either single binding of the form:

(variable initial-form)  

or a list of bindings of the form:

((variable-1 initial-form-1)
 (variable-2 initial-form-2)
 ...
 (variable-n initial-form-n))  

Each initial-form is executed in turn, and the variable bound to the corresponding value. Initial-form expressions can refer to variables previously bound by the when-let*.

Execution of when-let* stops immediately if any initial-form evaluates to nil. If all initial-forms evaluate to true, then forms are evaluated as an implicit progn.