think about blame

[cyrus-]

seems technically simple to add to the cast forms, and might have some benefits as far as debugging cast failures goes, but not sure what the relevant metatheoretic properties that we'd need to prove are -- need to do some research. @matthewhammer also has some general qualms about the entire notion. :)

[matthewhammer]

Just to clarify a few points related to my position:

1. The notion of blame as it appears in gradual typing seems to be striving to be a predicate about execution traces: Which execution trace(s) lead to the cast error in question?
2. Rather than characterize these calling contexts or execution traces logically in some open-ended way, which would be very difficult, blame uses the notion of static program labels.
3. In a "live programming" utopia, we'd have something richer than static program labels. :)