Module Data.Iterators

Provide Iterators for String and JArray

Imports

import frege.Prelude as Prelude
import Prelude.PreludeArrays as PreludeArrays
import Prelude.PreludeBase as PreludeBase
import Prelude.PreludeDecimal as PreludeDecimal
import Prelude.PreludeIO as PreludeIO
import Prelude.PreludeList as PreludeList
import Prelude.PreludeMonad as PreludeMonad
import Prelude.PreludeText as PreludeText
import Java.util.Regex as Regexp

Table of Content

Definitions

data ArrayIterator a

data StringIterator a
Instances

instance ListMonoid StringIterator

instance ListView ArrayIterator

instance ListView StringIterator
Functions and Values by Type

Definitions

data StringIterator a

A StringIterator is a data structure that lets us view a part of a String as a list.

With large Strings, performing list work on Strings can be expensive, because more recent JVMs implement the substring operation via copying.

Construction, ListView.drop, ListView.take, ListView.head and ListView.tail on a StringIterator are O(1) operations. The drawback is that it holds on to the underlying String.

Constructors

private SI {string ∷ StringJ a, at ∷ Int, limit ∷ Int}

Member Functions

at ∷ StringIterator α → Int: access field at
from ∷ StringJ α → StringIterator α: Construct a StringIterator from a String
limit ∷ StringIterator α → Int: access field limit
string ∷ StringIterator α → StringJ α: access field string
to ∷ StringIterator α → StringJ α: realize the substring indicated by this iterator

data ArrayIterator a

A ArrayIterator is a data structure that lets us view a part of a JArray as a list.

With large JArrays, doing ListSource.toList and iterating through the list can get expensive memory-wise.

Construction, ListView.drop, ListView.take, ListView.head and ListView.tail on a ArrayIterator are O(1) operations with a minimal memory overhead. The drawback is that it holds on to the underlying JArray.

Constructors

private AI {array ∷ JArray a, at ∷ Int, limit ∷ Int}

Member Functions

array ∷ ArrayIterator α → JArray α: access field array
at ∷ ArrayIterator α → Int: access field at
from ∷ JArray α → ArrayIterator α: make iterator from JArray
limit ∷ ArrayIterator α → Int: access field limit
to ∷ ArrayElement a ⇒ ArrayIterator a → JArray a: realize the subarray indicated by this iterator

Instances

instance ListMonoid StringIterator

Member Functions

++ ∷ StringIterator α → StringIterator α → StringIterator α
infixr 13: concatenate the strings described by two iterators
concat ∷ [StringIterator α] → StringIterator α: inherited from ListMonoid.concat

instance ListView ArrayIterator

Member Functions

drop ∷ Int → ArrayIterator α → ArrayIterator α

drop at most n characters by advancing the start index.

Can be abused to "go back" towards the beginning of the String

empty ∷ ArrayIterator α

create an empty ArrayIterator

head ∷ ArrayIterator α → α

inherited from ListView.head

length ∷ ArrayIterator α → Int

length

null ∷ ArrayIterator α → Bool

is it null?

tail ∷ ArrayIterator α → ArrayIterator α

inherited from ListView.tail

take ∷ Int → ArrayIterator α → ArrayIterator α

sets the ListView.length of the projection to n or 0, if n is negative.

toList ∷ ArrayIterator α → [α]

inherited from ListView.toList

uncons ∷ ArrayIterator α → Maybe (α, ArrayIterator α)

deconstruct

instance ListView StringIterator

Member Functions

drop ∷ Int → StringIterator α → StringIterator α

drop at most n characters by advancing the start index.

Can be abused to "go back" towards the beginning of the String

empty ∷ StringIterator α

empty StringIterator

head ∷ StringIterator α → α

inherited from ListView.head

length ∷ StringIterator α → Int

length

null ∷ StringIterator α → Bool

is it null?

tail ∷ StringIterator α → StringIterator α

inherited from ListView.tail

take ∷ Int → StringIterator α → StringIterator α

sets the ListView.length of the projection to n or 0, if n is negative.

toList ∷ StringIterator α → [α]

inherited from ListView.toList

uncons ∷ StringIterator α → Maybe (α, StringIterator α)

deconstruct

Functions and Values by Type

ArrayIterator α → (Int→Int) → ArrayIterator α: ArrayIterator.chg$at, ArrayIterator.chg$limit
ArrayIterator α → Int → ArrayIterator α: ArrayIterator.upd$at, ArrayIterator.upd$limit
ArrayIterator α → ArrayIterator α: ListView_ArrayIterator.tail
ArrayIterator α → JArray α: ArrayIterator.array
ArrayIterator α → Maybe (α, ArrayIterator α): ListView_ArrayIterator.uncons
ArrayIterator α → [α]: ListView_ArrayIterator.toList
ArrayIterator α → Bool: ListView_ArrayIterator.null
ArrayIterator α → Int: ListView_ArrayIterator.length, ArrayIterator.limit, ArrayIterator.at
ArrayIterator α → α: ListView_ArrayIterator.head
StringIterator α → (Int→Int) → StringIterator α: StringIterator.chg$at, StringIterator.chg$limit
StringIterator α → StringIterator α → StringIterator α: ListMonoid_StringIterator.++
StringIterator α → Int → StringIterator α: StringIterator.upd$limit, StringIterator.upd$at
StringIterator α → StringIterator α: ListView_StringIterator.tail
StringIterator α → Maybe (α, StringIterator α): ListView_StringIterator.uncons
StringIterator α → StringJ α: StringIterator.to, StringIterator.string
StringIterator α → [α]: ListView_StringIterator.toList
StringIterator α → Bool: ListView_StringIterator.null
StringIterator α → Int: ListView_StringIterator.length, StringIterator.limit, StringIterator.at
StringIterator α → α: ListView_StringIterator.head
JArray a → Int → Int → ArrayIterator a: ArrayIterator.AI
JArray α → ArrayIterator α: ArrayIterator.from
StringJ a → Int → Int → StringIterator a: StringIterator.SI
StringJ α → StringIterator α: StringIterator.from
[StringIterator α] → StringIterator α: ListMonoid_StringIterator.concat
Int → ArrayIterator α → ArrayIterator α: ListView_ArrayIterator.take, ListView_ArrayIterator.drop
Int → StringIterator α → StringIterator α: ListView_StringIterator.take, ListView_StringIterator.drop
α → Bool: ArrayIterator.has$at, ArrayIterator.has$limit, ArrayIterator.has$array, StringIterator.has$string, StringIterator.has$at, StringIterator.has$limit
ArrayElement a ⇒ ArrayIterator a → JArray a: ArrayIterator.to
ArrayIterator α: ListView_ArrayIterator.empty
StringIterator α: ListView_StringIterator.empty
ArrayIterator α → (JArray α→JArray β) → ArrayIterator β: ArrayIterator.chg$array
ArrayIterator α → JArray β → ArrayIterator β: ArrayIterator.upd$array
StringIterator α → (StringJ α→StringJ β) → StringIterator β: StringIterator.chg$string
StringIterator α → StringJ β → StringIterator β: StringIterator.upd$string