Return Values (ANSI and GNU Common Lisp Document)

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#### 3.1.7 Return Values

Ordinarily the result of calling a function is a single object. Sometimes, however, it is convenient for a function to compute several objects and return them.

In order to receive other than exactly one value from a form, one of several special forms or macros must be used to request those values. If a form produces multiple values which were not requested in this way, then the first value is given to the caller and all others are discarded; if the form produces zero values, then the caller receives nil as a value.

Figure 3–5 lists some operators for receiving multiple values_2. These operators can be used to specify one or more forms to evaluate and where to put the values returned by those forms.

      multiple-value-bind  multiple-value-prog1  return-from
      multiple-value-call  multiple-value-setq   throw
      multiple-value-list  return

      Figure 3–5: Some operators applicable to receiving multiple values

The function values can produce multiple values_2. `(values)` returns zero values; `(values form)` returns the primary value returned by form; `(values form1 form2)` returns two values, the primary value of form1 and the primary value of form2; and so on.

See multiple-values-limit and values-list.