Id (programming language)
{{other uses of|ID}}
Irvine Dataflow (Id) is a general-purpose parallel programming language, started at the University of California at Irvine in 1975{{cite book|title=Data Flow Computing: Theory and Practice|author=Sharp, J.A.|date=1992|publisher=Intellect, Limited|isbn=9780893919214|url=https://books.google.com/books?id=dS4b3i36qsEC|page=125|access-date=2014-12-02}} by Arvind and K. P. Gostelow.{{Cite journal |last=Arvind |last2=Gostelow |first2=Kim P. |last3=Plouffe |first3=Wil |date=1978 |title=The (preliminary) Id report: an asynchronous programming language and computing machine (revised) |url=https://escholarship.org/uc/item/0rr7573w |language=en |journal=Technical Report TR-114, Department of Information and Computer Science, University of California, Irvine}} 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."Concurrent Haskell". Peyton-Jones, Gordon and Finne. POPL 1996.
Examples
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 Fibonacci numbers:
typeof fib_array = int -> (array int);
def fib_array n =
{ A = { array (0,n) of
| [0] = 0
| [1] = 1
| [i] = A[i-1] + A[i-2] || i <- 2 to n }
In A };
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 = { A = x : A In A };
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);
Implementations
;pHluid
:The pHluid system was a research implementation of Id programming language, with future plans for a front-end for pH, a parallel dialect of the Haskell programming language, implemented at Digital's Cambridge Research Laboratory. and non-profit use. It is targeted at standard Unix workstation hardware.
References
External links
- [http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.18.4920 ID Language Reference Manual], Rishiyur S. Nikhil, 1991.
- "An Asynchronous Programming Language for a Large Multiprocessor Machine", Arvind et al., TR114a, Dept ISC, UC Irvine, Dec 1978
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