Irvine Dataflow (Id) is a general-purpose parallel programming language, started at the University of California at Irvine in 1975[1] by Arvind and K. P. Gostelow.[2] Arvind continued work with Id at MIT into the 1990s.
The major subset of Id is a purely functional programming language with non-strict semantics. Features include: higher-order functions, a Milner-style statically type-checked polymorphic type system with overloading, user defined types and pattern matching, and prefix and infix operators. It led to the development of pH, a parallel dialect of Haskell.
Id programs are fine grained implicitly parallel.
The MVar synchronisation variable abstraction in Haskell is based on Id's M-structures.[3]
Id supports algebraic datatypes, similar to ML, Haskell, or Miranda:
type bool = False | True;
Types are inferred by default, but may be annotated with a typeof declaration. Type variables use the syntax *0, *1, etc.
typeof id = *0 -> *0; def id x = x;
A function which uses an array comprehension to compute the first
n
typeof fib_array = int -> (array int); def fib_array n = ;
Note the use of non-strict evaluation in the recursive definition of the array A.
Id's lenient evaluation strategy allows cyclic datastructures by default. The following code makes a cyclic list, using the cons operator :.
def cycle x = ;
However, to avoid nonterminating construction of truly infinite structures, explicit delays must be annotated using #:
def count_up_from x = x :# count_up_from (x + 1);