Difference between revisions of "OCaml"
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== Conceptual differences == |
== Conceptual differences == |
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− | OCaml's <tt>let</tt> is non-recursive and strict by default, but has keywords <tt>rec</tt> (as in <tt>let rec</tt>) and <tt>lazy</tt> to introduce |
+ | OCaml's <tt>let</tt> is non-recursive and strict by default, but has keywords <tt>rec</tt> (as in <tt>let rec</tt>) and <tt>lazy</tt> to introduce more Haskellish behaviour. |
OCaml is ''impure''. Although it makes heavy use of immutable data, it also has mutable references and arrays available, and IO is performed by ordinary functions. |
OCaml is ''impure''. Although it makes heavy use of immutable data, it also has mutable references and arrays available, and IO is performed by ordinary functions. |
Revision as of 23:08, 11 December 2012
OCaml is a functional programming language in the ML family, an extension of the Caml language with object-oriented constructs.
This page aims to cover some of its differences from Haskell.
Syntactic dictionary
Language | Haskell | OCaml | Comments |
Anonymous functions |
\x y -> ... |
fun x y -> ... |
|
Multiple assignments |
let x = 4 y = 5 in ... |
let x = 4 and y = 5 in ... |
|
Types |
Int, Bool, (Double, Char), a |
int, bool, float * char, 'a |
float is a double type |
Type signatures |
const :: a -> b -> a |
const : 'a -> 'b -> 'a |
Signatures usually omitted in OCaml |
Type declarations |
data A = B Int | C Char Bool x = B 3 y = C 'a' True |
type a = B of int | C of char * bool let x = B 3 and y = C ('a', true) |
|
Parametrised types |
data D a = D (a -> a) data E a b = L a | R b |
type 'a d = D of ('a -> 'a) type ('a, 'b) e = L of 'a | R of 'b | |
Pattern matching |
case x of A x -> ... C a b -> ... |
match x with B x -> ... C (a, b) -> ... |
Conceptual differences
OCaml's let is non-recursive and strict by default, but has keywords rec (as in let rec) and lazy to introduce more Haskellish behaviour.
OCaml is impure. Although it makes heavy use of immutable data, it also has mutable references and arrays available, and IO is performed by ordinary functions.