id	summary	reporter	owner	description	type	status	priority	milestone	component	resolution	keywords	cc	planetversion	pltversion
255	define-type's error message adds extra parens	robby@…	plai	"This program:

  #lang planet plai/plai:1:16
  (define-type t (c))
  (type-case t (list 1) (c () 1))

produces the error message:

  type-case: this value ((1)) is not of the specified type

but the extra pair of parens is confusing. I think better to stick with the standard error message style, ie something like:

  type-case: expected a value from type t, got: (1)

"	enhancement	closed	minor		plai/plai.plt	fixed			(1 16)	4.2.4.2