X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=docs%2Fusers_guide%2Fglasgow_exts.xml;h=43e84394c085b4b308f3bf210fdbb589d81dba87;hp=5d1b5cf5f053bf3a3435740f51ee0a7a1c88d3f0;hb=58521c72cec262496dabf5fffb057d25ab17a0f7;hpb=432b9c9322181a3644083e3c19b7e240d90659e7 diff --git a/docs/users_guide/glasgow_exts.xml b/docs/users_guide/glasgow_exts.xml index 5d1b5cf..43e8439 100644 --- a/docs/users_guide/glasgow_exts.xml +++ b/docs/users_guide/glasgow_exts.xml @@ -109,7 +109,7 @@ While you really can use this stuff to write fast code, All these primitive data types and operations are exported by the library GHC.Prim, for which there is -detailed online documentation. +detailed online documentation. (This documentation is generated from the file compiler/prelude/primops.txt.pp.) @@ -874,7 +874,7 @@ As you can guess justOnes will evaluate to Just [1,1 -The Control.Monad.Fix library introduces the MonadFix class. It's definition is: +The Control.Monad.Fix library introduces the MonadFix class. Its definition is: class Monad m => MonadFix m where @@ -1001,7 +1001,7 @@ This name is not supported by GHC. Generalised list comprehensions are a further enhancement to the - list comprehension syntatic sugar to allow operations such as sorting + list comprehension syntactic sugar to allow operations such as sorting and grouping which are familiar from SQL. They are fully described in the paper Comprehensive comprehensions: comprehensions with "order by" and "group by", @@ -1042,7 +1042,7 @@ then f This statement requires that f have the type - forall a. [a] -> [a]. You can see an example of it's use in the + forall a. [a] -> [a]. You can see an example of its use in the motivating example, as this form is used to apply take 5. @@ -1269,6 +1269,44 @@ definitions; you must define such a function in prefix form. + +Tuple sections + + + The flag enables Python-style partially applied + tuple constructors. For example, the following program + + (, True) + + is considered to be an alternative notation for the more unwieldy alternative + + \x -> (x, True) + +You can omit any combination of arguments to the tuple, as in the following + + (, "I", , , "Love", , 1337) + +which translates to + + \a b c d -> (a, "I", b, c, "Love", d, 1337) + + + + + If you have unboxed tuples enabled, tuple sections + will also be available for them, like so + + (# , True #) + +Because there is no unboxed unit tuple, the following expression + + (# #) + +continues to stand for the unboxed singleton tuple data constructor. + + + + Record field disambiguation @@ -2579,7 +2617,7 @@ constructor). -It's is permitted to declare an ordinary algebraic data type using GADT-style syntax. +It is permitted to declare an ordinary algebraic data type using GADT-style syntax. What makes a GADT into a GADT is not the syntax, but rather the presence of data constructors whose result type is not just T a b. @@ -4298,7 +4336,7 @@ type family Elem c example, consider the following declaration: type family F a b :: * -> * -- F's arity is 2, - -- although it's overall kind is * -> * -> * -> * + -- although its overall kind is * -> * -> * -> * Given this declaration the following are examples of well-formed and malformed types: