[previous] [up] [next]     [contents]
Next: Polymorphic Annotations Up: Extensions to DrScheme Previous: Extensions to DrScheme

Type Assertions

The form (: exp type) is an assertion that the values produced by exp must be contained in type. If MrSpidey is unable to prove that the type assertion is satisfied, then a warning is reported in the summary window. These : forms evaluate to void.



PLT