ghc-7.6.1.20121122: The GHC API

Safe HaskellNone

BasicTypes

Synopsis

Documentation

type Arity = IntSource

The number of value arguments that can be applied to a value before it does real work. So: fib 100 has arity 0 x -> fib x has arity 1

type RepArity = IntSource

The number of represented arguments that can be applied to a value before it does real work. So: fib 100 has representation arity 0 x -> fib x has representation arity 1 () -> fib (x + y) has representation arity 2

data OverlapFlag Source

Constructors

NoOverlap

This instance must not overlap another

Fields

isSafeOverlap :: Bool
 
OverlapOk

Silently ignore this instance if you find a more specific one that matches the constraint you are trying to resolve

Example: constraint (Foo [Int]) instances (Foo [Int]) (Foo [a]) OverlapOk Since the second instance has the OverlapOk flag, the first instance will be chosen (otherwise its ambiguous which to choose)

Fields

isSafeOverlap :: Bool
 
Incoherent

Like OverlapOk, but also ignore this instance if it doesn't match the constraint you are trying to resolve, but could match if the type variables in the constraint were instantiated

Example: constraint (Foo [b]) instances (Foo [Int]) Incoherent (Foo [a]) Without the Incoherent flag, we'd complain that instantiating b would change which instance was chosen

Fields

isSafeOverlap :: Bool
 

data Boxity Source

Constructors

Boxed 
Unboxed 

data OccInfo Source

Identifier occurrence information

Constructors

NoOccInfo

There are many occurrences, or unknown occurences

IAmDead

Marks unused variables. Sometimes useful for lambda and case-bound variables.

OneOcc !InsideLam !OneBranch !InterestingCxt

Occurs exactly once, not inside a rule

IAmALoopBreaker !RulesOnly

This identifier breaks a loop of mutually recursive functions. The field marks whether it is only a loop breaker due to a reference in a rule

Instances

data EP a Source

Constructors

EP 

Fields

fromEP :: a
 
toEP :: a