condition-form—a form; evaluated to produce a condition.
condition—a condition object resulting from the evaluation of condition-form.
restart-form—a form; evaluated to produce a restart-list.
restart-list—a list of restart objects resulting from the evaluation of restart-form.
forms—an implicit progn; evaluated.
results—the values returned by forms.
First, the condition-form and restarts-form are evaluated in normal left-to-right order; the primary values yielded by these evaluations are respectively called the condition and the restart-list.
Next, the forms are evaluated in a dynamic environment in which each restart in restart-list is associated with the condition. See Section 188.8.131.52.4 (Associating a Restart with a Condition).
Usually this macro is not used explicitly in code,
restart-case handles most of the common cases
in a way that is syntactically more concise.