A data type which contains itself. The commonest example is
the list type, in Haskell:
data List a = Nil | Cons a (List a)
which says a list of a's is either an empty list or a cons
cell containing an 'a' (the "head" of the list) and another
list (the "tail").
Recursion is not allowed in Miranda or Haskell synonym
types, so the following Haskell types are illegal:
type Bad = (Int, Bad)
type Evil = Bool -> Evil
whereas the seeminly equivalent algebraic data types are
acceptable:
data Good = Pair Int Good
data Fine = Fun (Bool->Fine)
Nearby terms:
recursive descent parser « Recursive Functional Algorithmic Language « Recursive Macro Actuated Generator « recursive type » Red » Red Book » Red Brick Intelligent SQL
