diff options
Diffstat (limited to 'petty-types.lisp')
| -rw-r--r-- | petty-types.lisp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/petty-types.lisp b/petty-types.lisp index 1d092b9..994f2e9 100644 --- a/petty-types.lisp +++ b/petty-types.lisp @@ -41,3 +41,6 @@ "Type specifier for vectors all of the same TYPE." `(satisfies ,(sequence-of-predicate-for 'vector type len))) +(deftype optional (type) + "Type specifier for an optional type." + `(or null ,type)) |