Data.HtsSet

HtsSet is a Heterogenous Set wich can provide storing values with different type.

These modules are intended to be imported qualified, to avoid name clashes with Prelude functions, e.g.

 import qualified Data.HtsSet as HSet

Documentation

data HtsSet

empty :: HtsSet

The empty HtsSet

singleton :: forall a. Typeable a => a -> HtsSet

A HtsSet with an element

null :: HtsSet -> Bool

Is the HtsSet is empty?

null empty == True
null (singleton "a") == False

size :: HtsSet -> Int

The number of elements in the HtsSet

size empty == 0
size (singleton "a") == 1

member :: forall proxy a. Typeable a => proxy a -> HtsSet -> Bool

The HtsSet is contain a same type of element?

member (Proxy :: Proxy String) empty == False
member (Proxy :: Proxy String) (singleton "a") == True

notMember :: forall proxy a. Typeable a => proxy a -> HtsSet -> Bool

The HtsSet is not contain a same type of element?

insert :: forall a. Typeable a => a -> HtsSet -> HtsSet

Insert a new value in the HtsSet. If the a elem is already present in the HtsSet with type, the associated value is replaced with the supplied value

insert "a" $ insert (2 :: Int) $ insert 'c' $ empty

lookup :: forall a. Typeable a => HtsSet -> Maybe a

Lookup a value from in the HtsSet

let hs = insert "a" $ insert (2 :: Int) $ insert 'c' $ empty
lookup hs == Just "a"
lookup hs == Just (2 :: Int)
but
lookup hs == Just 2 -- is False! Because the type of 2 is Num t => t not Int

lookupWithDefault :: forall a. Typeable a => a -> HtsSet -> a

Lookup a value from in the HtsSet with a default value

update :: forall a. Typeable a => (a -> a) -> HtsSet -> HtsSet

Update a value in HtsSet

let hs = insert "a" $ insert (2 :: Int) $ insert 'c' $ empty
let hs' = update (++"b") hs
lookup hs' == Just "ab"

existTypeOf :: forall a. Typeable a => a -> HtsSet -> Bool

The HtsSet is contain a same type of element?

let hs = insert "a" $ insert (2 :: Int) $ insert 'c' $ empty
existTypeOf "string" hs == True

existTypeOfP :: forall proxy a. Typeable a => proxy a -> HtsSet -> Bool

The HtsSet is contain a same type of element? (by proxy)

data a :+ b infixr 5

Helper heterogeneous list for comfortable HtsSet building (with append and fill)

let hs = fill ("a" :+ 'c' :+ True :+ ())
lookup hs == Just 'c'
use () to close the list
lookup hs == Just () -- is False!
let hs' = fill ("a" :+ 'c' :+ True :+ () :+ ())
lookup hs' == Just () -- is Ok

Constructors

a :+ b infixr 5

Instances

(Typeable * a, Append b) => Append ((:+) a b)

Methods

append :: (a :+ b) -> HtsSet -> HtsSet

class Append a where

Minimal complete definition

append

Methods

append :: a -> HtsSet -> HtsSet

Instances

Append ()

Methods

append :: () -> HtsSet -> HtsSet

(Typeable * a, Append b) => Append ((:+) a b)

Methods

append :: (a :+ b) -> HtsSet -> HtsSet

fill :: Append a => a -> HtsSet