Copyright | (c) Michal Konecny |
---|---|
License | BSD3 |
Maintainer | mikkonecny@gmail.com |
Stability | experimental |
Portability | portable |
Safe Haskell | None |
Language | Haskell98 |
This module defines fixed-type integer and rational literals.
This is useful when deriving the type of an expression bottom-up.
Eg we would not be able to write 1 < x
when the type of <
does not force the two sides to be of the
same type. We would need to write eg (1::Integer) < x
with
Prelude's generic literals.
Moreover, convenient conversion functions are provided for the most common numeric types. Thus one can say eg:
take (int 1)
integer (length list)
.double 0.5
To avoid integer overflow, no aritmetic operations return Int
.
Nevertheless, one can usually mix Int
with other types in expressions.
Any approximate arithmetic, ie arithmetic involving Doubles, returns
values of type Double
.
Double
values cannot be easily converted to exact
types such as Rational
or Integer
so that all such
conversions are clearly visible as labelled as inexact.
- fromInteger :: Integer -> Integer
- fromRational :: Rational -> Rational
- class HasIfThenElse b t where
- type CanBeInteger t = ConvertibleExactly t Integer
- integer :: CanBeInteger t => t -> Integer
- integers :: CanBeInteger t => [t] -> [Integer]
- type HasIntegers t = ConvertibleExactly Integer t
- fromInteger_ :: HasIntegers t => Integer -> t
- type CanBeInt t = ConvertibleExactly t Int
- int :: CanBeInt t => t -> Int
- ints :: CanBeInt t => [t] -> [Int]
- type CanBeRational t = ConvertibleExactly t Rational
- rational :: CanBeRational t => t -> Rational
- rationals :: CanBeRational t => [t] -> [Rational]
- type HasRationals t = ConvertibleExactly Rational t
- fromRational_ :: HasRationals t => Rational -> t
- type CanBeDouble t = Convertible t Double
- double :: CanBeDouble t => t -> Double
- doubles :: CanBeDouble t => [t] -> [Double]
- class ConvertibleExactly t1 t2 where
- convertExactly :: ConvertibleExactly t1 t2 => t1 -> t2
- convertExactlyTargetSample :: ConvertibleExactly t1 t2 => t2 -> t1 -> t2
- type ConvertResult a = Either ConvertError a
- data ConvertError :: *
- convError :: (Show a, Typeable * a, Typeable * b) => String -> a -> ConvertResult b
- (!!) :: CanBeInteger t => [a] -> t -> a
- specCanBeInteger :: (CanBeInteger t, Show t, Arbitrary t) => T t -> Spec
- printArgsIfFails2 :: (Testable prop, Show a, Show b) => String -> (a -> b -> prop) -> a -> b -> Property
- data T t = T String
- tInt :: T Int
- tInteger :: T Integer
- tRational :: T Rational
- tDouble :: T Double
- tBool :: T Bool
- tMaybe :: T t -> T (Maybe t)
- tMaybeBool :: T (Maybe Bool)
- tMaybeMaybeBool :: T (Maybe (Maybe Bool))
- convertFirst :: ConvertibleExactly a b => (b -> b -> c) -> a -> b -> c
- convertSecond :: ConvertibleExactly b a => (a -> a -> c) -> a -> b -> c
- convertFirstUsing :: (a -> b -> b) -> (b -> b -> c) -> a -> b -> c
- convertSecondUsing :: (a -> b -> a) -> (a -> a -> c) -> a -> b -> c
Fixed-type literals
fromInteger :: Integer -> Integer Source #
Replacement for fromInteger
using the RebindableSyntax extension.
This version of fromInteger arranges that integer literals
are always of type Integer
.
fromRational :: Rational -> Rational Source #
Replacement for fromRational
using the RebindableSyntax extension.
This version of fromRational arranges that rational literals are
always of type Rational
.
Generalised if-then-else
class HasIfThenElse b t where Source #
Restore if-then-else with RebindableSyntax
ifThenElse :: b -> t -> t -> t Source #
Convenient conversions
type CanBeInteger t = ConvertibleExactly t Integer Source #
integer :: CanBeInteger t => t -> Integer Source #
integers :: CanBeInteger t => [t] -> [Integer] Source #
type HasIntegers t = ConvertibleExactly Integer t Source #
fromInteger_ :: HasIntegers t => Integer -> t Source #
type CanBeInt t = ConvertibleExactly t Int Source #
type CanBeRational t = ConvertibleExactly t Rational Source #
rational :: CanBeRational t => t -> Rational Source #
rationals :: CanBeRational t => [t] -> [Rational] Source #
type HasRationals t = ConvertibleExactly Rational t Source #
fromRational_ :: HasRationals t => Rational -> t Source #
type CanBeDouble t = Convertible t Double Source #
double :: CanBeDouble t => t -> Double Source #
doubles :: CanBeDouble t => [t] -> [Double] Source #
class ConvertibleExactly t1 t2 where Source #
Define our own ConvertibleExactly since convertible is too relaxed for us. For example, convertible allows conversion from Rational to Integer, rounding to nearest integer. We prefer to allow only exact conversions.
safeConvertExactly :: t1 -> ConvertResult t2 Source #
safeConvertExactly :: Convertible t1 t2 => t1 -> ConvertResult t2 Source #
ConvertibleExactly Double Double Source # | |
ConvertibleExactly Int Double Source # | |
ConvertibleExactly Int Int Source # | |
ConvertibleExactly Int Integer Source # | |
ConvertibleExactly Int Rational Source # | |
ConvertibleExactly Integer Double Source # | |
ConvertibleExactly Integer Int Source # | |
ConvertibleExactly Integer Integer Source # | |
ConvertibleExactly Integer Rational Source # | |
ConvertibleExactly Rational Rational Source # | |
(ConvertibleExactly Bool t0, Monoid es0) => ConvertibleExactly Bool (CollectErrors es0 t0) Source # | |
(ConvertibleExactly Double t0, Monoid es0) => ConvertibleExactly Double (CollectErrors es0 t0) Source # | |
(ConvertibleExactly Int t0, Monoid es0) => ConvertibleExactly Int (CollectErrors es0 t0) Source # | |
(ConvertibleExactly Integer t0, Monoid es0) => ConvertibleExactly Integer (CollectErrors es0 t0) Source # | |
(ConvertibleExactly Rational t0, Monoid es0) => ConvertibleExactly Rational (CollectErrors es0 t0) Source # | |
convertExactly :: ConvertibleExactly t1 t2 => t1 -> t2 Source #
convertExactlyTargetSample :: ConvertibleExactly t1 t2 => t2 -> t1 -> t2 Source #
type ConvertResult a = Either ConvertError a #
The result of a safe conversion via safeConvert
.
data ConvertError :: * #
How we indicate that there was an error.
Generic list index
(!!) :: CanBeInteger t => [a] -> t -> a Source #
specCanBeInteger :: (CanBeInteger t, Show t, Arbitrary t) => T t -> Spec Source #
HSpec properties that each implementation of CanBeInteger should satisfy.
printArgsIfFails2 :: (Testable prop, Show a, Show b) => String -> (a -> b -> prop) -> a -> b -> Property Source #
Testing support functions
A runtime representative of type t
.
Used for specialising polymorphic tests to concrete types.
Helper functions
:: ConvertibleExactly a b | |
=> (b -> b -> c) | same-type operation |
-> a -> b -> c | mixed-type operation |
:: ConvertibleExactly b a | |
=> (a -> a -> c) | same-type operation |
-> a -> b -> c | mixed-type operation |
:: (a -> b -> b) | conversion function |
-> (b -> b -> c) | same-type operation |
-> a -> b -> c | mixed-type operation |
:: (a -> b -> a) | conversion function |
-> (a -> a -> c) | same-type operation |
-> a -> b -> c | mixed-type operation |