amber/src/Kernel-Collections.st

Smalltalk createPackage: 'Kernel-Collections'!
Object subclass: #Association
	instanceVariableNames: 'key value'
	package: 'Kernel-Collections'!
!Association commentStamp!
I represent a pair of associated objects, a key and a value. My instances can serve as entries in a dictionary.

Instances can be created with the class-side method `#key:value:`!

!Association methodsFor: 'accessing'!

key
	^ key
!

key: aKey
	key := aKey
!

value
	^ value
!

value: aValue
	value := aValue
! !

!Association methodsFor: 'comparing'!

= anAssociation
	^ self class = anAssociation class and: [
		self key = anAssociation key and: [
		self value = anAssociation value ]]
! !

!Association methodsFor: 'printing'!

printOn: aStream
	self key printOn: aStream.
	aStream nextPutAll: ' -> '.
	self value printOn: aStream
! !

!Association class methodsFor: 'instance creation'!

key: aKey value: aValue
		^ self new
		key: aKey;
		value: aValue;
		yourself
! !

Object subclass: #BucketStore
	instanceVariableNames: 'buckets hashBlock'
	package: 'Kernel-Collections'!
!BucketStore commentStamp!
I am an helper class for hash-based stores.

I hold buckets which are selected by a hash, specified using `#hashBlock:`.
The hash can be any object, and
it is used as a JS property (that is, in ES5
its toString() value counts).

## API
I maintain a list of buckets. Client code can use this API:
 - `#bucketOfElement:` (to ask a bucket for element, I can return JS null if n/a)
 - `#do:` (to enumerate all elements of all buckets)
 - `#removeAll` (to remove all buckets)

Client code itself should add/remove elements
in a bucket. The `nil` object should not be put into any bucket.

Types of buckets are the responsibility of subclasses via `#newBucket`.!

!BucketStore methodsFor: 'accessing'!

bucketOfElement: anObject
	<
		var hash = self['@hashBlock'](anObject);
		if (!!hash) return null;
		var buckets = self['@buckets'],
			bucket = buckets[hash];
		if (!!bucket) { bucket = buckets[hash] = self._newBucket(); }
		return bucket;
	>
!

hashBlock: aBlock
	hashBlock := aBlock
! !

!BucketStore methodsFor: 'adding/removing'!

removeAll
	<self['@buckets'] = Object.create(null);>
! !

!BucketStore methodsFor: 'enumerating'!

do: aBlock
	<
		var buckets = self['@buckets'];
		var keys = Object.keys(buckets);
		for (var i = 0; i < keys.length; ++i) { buckets[keys[i]]._do_(aBlock); }
	>
! !

!BucketStore methodsFor: 'initialization'!

initialize
	super initialize.
	self removeAll
! !

!BucketStore methodsFor: 'private'!

newBucket
	self subclassResponsibility
! !

!BucketStore class methodsFor: 'instance creation'!

hashBlock: aBlock
	^ self new
		hashBlock: aBlock;
		yourself
! !

BucketStore subclass: #ArrayBucketStore
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!ArrayBucketStore commentStamp!
I am a concrete `BucketStore` with buckets being instance of `Array`.!

!ArrayBucketStore methodsFor: 'private'!

newBucket
	^ #()
! !

Object subclass: #Collection
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!Collection commentStamp!
I am the abstract superclass of all classes that represent a group of elements.

I provide a set of useful methods to the Collection hierarchy such as enumerating and converting methods.!

!Collection methodsFor: 'accessing'!

occurrencesOf: anObject
	"Answer how many of the receiver's elements are equal to anObject."

	| tally |
	tally := 0.
	self do: [ :each | anObject = each ifTrue: [ tally := tally + 1 ]].
	^ tally
!

size
	self subclassResponsibility
! !

!Collection methodsFor: 'adding/removing'!

add: anObject
	self subclassResponsibility
!

addAll: aCollection
	aCollection do: [ :each |
		self add: each ].
	^ aCollection
!

anyOne
	"Answer a representative sample of the receiver. This method can
	be helpful when needing to preinfer the nature of the contents of 
	semi-homogeneous collections."

	self ifEmpty: [ self error: 'Collection is empty' ].
	self do: [ :each | ^ each ]
!

remove: anObject
	^ self remove: anObject ifAbsent: [ self errorNotFound ]
!

remove: anObject ifAbsent: aBlock
	self subclassResponsibility
!

removeAll
	self subclassResponsibility
! !

!Collection methodsFor: 'converting'!

asArray
	^ Array withAll: self
!

asJSON
	^ self asArray collect: [ :each | each asJSON ]
!

asOrderedCollection
	^ self asArray
!

asSet
	^ Set withAll: self
! !

!Collection methodsFor: 'copying'!

, aCollection
	^ self copy
		addAll: aCollection;
		yourself
!

copyWith: anObject
	^ self copy add: anObject; yourself
!

copyWithAll: aCollection
	^ self copy addAll: aCollection; yourself
!

copyWithoutAll: aCollection
	"Answer a copy of the receiver that does not contain any elements
	equal to those in aCollection."

	^ self reject: [ :each | aCollection includes: each ]
! !

!Collection methodsFor: 'enumerating'!

allSatisfy: aBlock
	"Evaluate aBlock with the elements of the receiver.
	If aBlock returns false for any element return false.
	Otherwise return true."

	self do: [ :each | (aBlock value: each) ifFalse: [ ^ false ] ].
	^ true
!

anySatisfy: aBlock
	"Evaluate aBlock with the elements of the receiver.
	If aBlock returns true for any element return true.
	Otherwise return false."

	self do: [ :each | (aBlock value: each) ifTrue: [ ^ true ] ].
	^ false
!

collect: aBlock
	| stream |
	stream := self class new writeStream.
	self do: [ :each |
		stream nextPut: (aBlock value: each) ].
	^ stream contents
!

detect: aBlock
	^ self detect: aBlock ifNone: [ self errorNotFound ]
!

detect: aBlock ifNone: anotherBlock
	self subclassResponsibility
!

do: aBlock
	self subclassResponsibility
!

do: aBlock separatedBy: anotherBlock
	| actionBeforeElement |
	actionBeforeElement := [ actionBeforeElement := anotherBlock ].
	self do: [ :each |
		actionBeforeElement value.
		aBlock value: each ]
!

inject: anObject into: aBlock
	| result |
	result := anObject.
	self do: [ :each |
		result := aBlock value: result value: each ].
	^ result
!

intersection: aCollection
	"Answer the set theoretic intersection of two collections."

	| set outputSet |
	
	set := self asSet.
	outputSet := Set new.
	
	aCollection do: [ :each |
		((set includes: each) and: [ (outputSet includes: each) not ])
			ifTrue: [
				outputSet add: each ]].
		
	^ self class withAll: outputSet asArray
!

noneSatisfy: aBlock
	"Evaluate aBlock with the elements of the receiver.
	If aBlock returns false for all elements return true.
	Otherwise return false"

	self do: [ :item | (aBlock value: item) ifTrue: [ ^ false ] ].
	^ true
!

reject: aBlock
	^ self select: [ :each | (aBlock value: each) = false ]
!

select: aBlock
	| stream |
	stream := self class new writeStream.
	self do: [ :each |
		(aBlock value: each) ifTrue: [
		stream nextPut: each ] ].
	^ stream contents
!

select: selectBlock thenCollect: collectBlock
	| stream |
	stream := self class new writeStream.
	self do: [ :each |
		(selectBlock value: each) ifTrue: [
		stream nextPut: (collectBlock value: each) ] ].
	^ stream contents
! !

!Collection methodsFor: 'error handling'!

errorNotFound
	self error: 'Object is not in the collection'
! !

!Collection methodsFor: 'streaming'!

putOn: aStream
	self do: [ :each | each putOn: aStream ]
! !

!Collection methodsFor: 'testing'!

ifEmpty: aBlock
	"Evaluate the given block with the receiver as argument, answering its value if the receiver is empty, otherwise answer the receiver. 
	Note that the fact that this method returns its argument in case the receiver is not empty allows one to write expressions like the following ones: 
		self classifyMethodAs:
			(myProtocol ifEmpty: ['As yet unclassified'])"
	^ self isEmpty
		ifTrue: aBlock
		ifFalse: [ self ]
!

ifEmpty: aBlock ifNotEmpty: anotherBlock
	^ self isEmpty
		ifTrue: aBlock
		ifFalse: [ anotherBlock value: self ]
!

ifNotEmpty: aBlock
	^ self notEmpty
		ifTrue: [ aBlock value: self ]
		ifFalse: [ self ]
!

ifNotEmpty: aBlock ifEmpty: anotherBlock
	^ self notEmpty
		ifTrue: [ aBlock value: self ]
		ifFalse: anotherBlock
!

includes: anObject
	^ self anySatisfy: [ :each | each = anObject ]
!

isEmpty
	^ self size = 0
!

notEmpty
	^ self isEmpty not
! !

!Collection class methodsFor: 'accessing'!

classTag
	"Returns a tag or general category for this class.
	Typically used to help tools do some reflection.
	Helios, for example, uses this to decide what icon the class should display."
	
	^ 'collection'
! !

!Collection class methodsFor: 'instance creation'!

new: anInteger
	^ self new
!

with: anObject
		^ self new
		add: anObject;
		yourself
!

with: anObject with: anotherObject
		^ self new
		add: anObject;
		add: anotherObject;
		yourself
!

with: firstObject with: secondObject with: thirdObject
		^ self new
		add: firstObject;
		add: secondObject;
		add: thirdObject;
		yourself
!

withAll: aCollection
		^ self new
		addAll: aCollection;
		yourself
! !

Collection subclass: #IndexableCollection
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!IndexableCollection commentStamp!
I am a key-value store collection, that is,
I store values under indexes.

As a rule of thumb, if a collection has `#at:` and `#at:put:`,
it is an IndexableCollection.!

!IndexableCollection methodsFor: 'accessing'!

at: anIndex
	"Lookup the given index in the receiver.
	If it is present, answer the value stored at anIndex.
	Otherwise, raise an error."

	^ self at: anIndex ifAbsent: [ self errorNotFound ]
!

at: anIndex ifAbsent: aBlock
	"Lookup the given index in the receiver.
	If it is present, answer the value stored at anIndex.
	Otherwise, answer the value of aBlock."

	self subclassResponsibility
!

at: aKey ifAbsentPut: aBlock
	^ self at: aKey ifAbsent: [
		self at: aKey put: aBlock value ]
!

at: anIndex ifPresent: aBlock
	"Lookup the given index in the receiver.
	If it is present, answer the value of evaluating aBlock with the value stored at anIndex.
	Otherwise, answer nil."

	^ self at: anIndex ifPresent: aBlock ifAbsent: [ nil ]
!

at: anIndex ifPresent: aBlock ifAbsent: anotherBlock
	"Lookup the given index in the receiver.
	If it is present, answer the value of evaluating aBlock with the value stored at anIndex.
	Otherwise, answer the value of anotherBlock."

	self subclassResponsibility
!

at: anIndex put: anObject
	"Store anObject under the given index in the receiver."

	self subclassResponsibility
!

indexOf: anObject
	"Lookup index at which anObject is stored in the receiver.
	If not present, raise an error."

	^ self indexOf: anObject ifAbsent: [ self errorNotFound ]
!

indexOf: anObject ifAbsent: aBlock
	"Lookup index at which anObject is stored in the receiver.
	If not present, return value of executing aBlock."

	self subclassResponsibility
! !

!IndexableCollection methodsFor: 'enumerating'!

with: anotherCollection do: aBlock
	"Calls aBlock with every value from self
	and with indetically-indexed value from anotherCollection"

	self withIndexDo: [ :each :index |
		aBlock value: each value: (anotherCollection at: index) ]
!

withIndexDo: aBlock
	"Calls aBlock with every value from self
	and with its index as the second argument"

	self subclassResponsibility
! !

IndexableCollection subclass: #AssociativeCollection
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!AssociativeCollection commentStamp!
I am a base class for object-indexed collections (Dictionary et.al.).!

!AssociativeCollection methodsFor: 'accessing'!

associations
	| associations |
	associations := #().
	self associationsDo: [ :each | associations add: each ].
	^ associations
!

at: aKey ifPresent: aBlock ifAbsent: anotherBlock
	"Lookup the given key in the receiver.
	If it is present, answer the value of evaluating the oneArgBlock 
	with the value associated with the key, otherwise answer the value 
	of absentBlock."
	
	^ (self includesKey: aKey)
		ifTrue: [ aBlock value: (self at: aKey) ]
		ifFalse: [ anotherBlock value ]
!

indexOf: anObject ifAbsent: aBlock
	^ self keys 
		detect: [ :each | (self at: each) = anObject ] 
		ifNone: aBlock
!

keyAtValue: anObject
	^ self keyAtValue: anObject ifAbsent: [ self errorNotFound ]
!

keyAtValue: anObject ifAbsent: aBlock
	^ self indexOf: anObject ifAbsent: aBlock
!

keys
	self subclassResponsibility
!

size
	^ self keys size
!

values
	self subclassResponsibility
! !

!AssociativeCollection methodsFor: 'adding/removing'!

add: anAssociation
	self at: anAssociation key put: anAssociation value
!

addAll: anAssociativeCollection
	super addAll: anAssociativeCollection associations.
	^ anAssociativeCollection
!

remove: aKey ifAbsent: aBlock
	^ self removeKey: aKey ifAbsent: aBlock
!

removeAll
	^ self keys do: [ :each | self removeKey: each ]
!

removeKey: aKey
	^ self remove: aKey
!

removeKey: aKey ifAbsent: aBlock
	self subclassResponsibility
! !

!AssociativeCollection methodsFor: 'comparing'!

= anAssocitativeCollection
	self class = anAssocitativeCollection class ifFalse: [ ^ false ].
	self size = anAssocitativeCollection size ifFalse: [ ^ false ].
	^ self associations = anAssocitativeCollection associations
! !

!AssociativeCollection methodsFor: 'converting'!

asDictionary
	^ Dictionary from: self associations
!

asHashedCollection
	^ HashedCollection from: self associations
!

asJSON
	| hash |
	hash := HashedCollection new.
	self keysAndValuesDo: [ :key :value |
		hash at: key put: value asJSON ].
	^ hash
! !

!AssociativeCollection methodsFor: 'copying'!

deepCopy
	| copy |
	copy := self class new.
	self keysAndValuesDo: [ :key :value |
		copy at: key put: value deepCopy ].
	^ copy
!

shallowCopy
	| copy |
	copy := self class new.
	self keysAndValuesDo: [ :key :value |
		copy at: key put: value ].
	^ copy
! !

!AssociativeCollection methodsFor: 'enumerating'!

associationsDo: aBlock
	self keysAndValuesDo: [ :key :value |
		aBlock value: (Association key: key value: value) ]
!

collect: aBlock
	| newDict |
	newDict := self class new.
	self keysAndValuesDo: [ :key :value |
		newDict at: key put: (aBlock value: value) ].
	^ newDict
!

detect: aBlock ifNone: anotherBlock
	^ self values detect: aBlock ifNone: anotherBlock
!

do: aBlock
	self valuesDo: aBlock
!

includes: anObject
	^ self values includes: anObject
!

keysAndValuesDo: aBlock
	self keysDo: [ :each |
		aBlock value: each value: (self at: each) ]
!

keysDo: aBlock
	self subclassResponsibility
!

select: aBlock
	| newDict |
	newDict := self class new.
	self keysAndValuesDo: [ :key :value |
		(aBlock value: value) ifTrue: [ newDict at: key put: value ]].
	^ newDict
!

valuesDo: aBlock
	self subclassResponsibility
!

withIndexDo: aBlock
	self keysAndValuesDo: [ :key :value | aBlock value: value value: key ]
! !

!AssociativeCollection methodsFor: 'printing'!

printOn: aStream
	super printOn: aStream.
	
	aStream nextPutAll: ' ('.
	self associations
		do: [ :each | each printOn: aStream ]
		separatedBy: [ aStream nextPutAll: ' , ' ].
	aStream nextPutAll: ')'
! !

!AssociativeCollection methodsFor: 'testing'!

includesKey: aKey
	self subclassResponsibility
! !

!AssociativeCollection class methodsFor: 'instance creation'!

from: aCollection
	| newCollection |
	newCollection := self new.
	aCollection do: [ :each | newCollection add: each ].
	^ newCollection
!

fromPairs: aCollection
	"This message is poorly named and has been replaced by #from:"
	^ self from: aCollection
!

newFromPairs: aCollection
	"Accept an array of elements where every two elements form an 
	association - the odd element being the key, and the even element the value."
	
	| newCollection |
	
	aCollection size even ifFalse: [ 
		self error: '#newFromPairs only accepts arrays of an even length' ].
		
	newCollection := self new.
	( 1 to: aCollection size by: 2 ) do: [ :each | 
		newCollection at: (aCollection at: each) put: (aCollection at: each + 1) ].
		
	^ newCollection
! !

AssociativeCollection subclass: #Dictionary
	instanceVariableNames: 'keys values'
	package: 'Kernel-Collections'!
!Dictionary commentStamp!
I represent a set of elements that can be viewed from one of two perspectives: a set of associations,
or a container of values that are externally named where the name can be any object that responds to `=`.

The external name is referred to as the key.!

!Dictionary methodsFor: 'accessing'!

at: aKey ifAbsent: aBlock
	<
		var index = self._positionOfKey_(aKey);
		return index >>=0 ? self['@values'][index] : aBlock._value();
	>
!

at: aKey put: aValue
	<
		var index = self._positionOfKey_(aKey);
		if(index === -1) {
			var keys = self['@keys'];
			index = keys.length;
			keys.push(aKey);
		}

		return self['@values'][index] = aValue;
	>
!

indexOf: anObject ifAbsent: aBlock
	| index |
	index := values 
		indexOf: anObject 
		ifAbsent: [ 0 ].
	^ index = 0 
		ifTrue: [ aBlock value ] 
		ifFalse: [ keys at: index ]
!

keys
	^ keys copy
!

values
	^ values
! !

!Dictionary methodsFor: 'adding/removing'!

removeAll
	keys removeAll.
	values removeAll
!

removeKey: aKey ifAbsent: aBlock
	<
		var index = self._positionOfKey_(aKey);
		if(index === -1) {
			return aBlock._value()
		} else {
			var keys = self['@keys'], values = self['@values'];
			var value = values[index], l = keys.length;
			keys[index] = keys[l-1];
			keys.pop();
			values[index] = values[l-1];
			values.pop();
			return value;
		}
	>
! !

!Dictionary methodsFor: 'enumerating'!

keysAndValuesDo: aBlock
	^ keys with: values do: aBlock
!

keysDo: aBlock
	^ keys do: aBlock
!

valuesDo: aBlock
	^ values do: aBlock
! !

!Dictionary methodsFor: 'initialization'!

initialize
	super initialize.
	keys := #().
	values := #()
! !

!Dictionary methodsFor: 'private'!

positionOfKey: anObject
	<
		var keys = self['@keys'];
		for(var i=0;i<keys.length;i++){
			if(keys[i].__eq(anObject)) { return i;}
		}
		return -1;
	>
! !

!Dictionary methodsFor: 'testing'!

includesKey: aKey
	< return self._positionOfKey_(aKey) >>= 0; >
! !

AssociativeCollection subclass: #HashedCollection
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!HashedCollection commentStamp!
I am a traditional JavaScript object, or a Smalltalk `Dictionary`.

Unlike a `Dictionary`, I can only have strings as keys.!

!HashedCollection methodsFor: 'accessing'!

at: aKey ifAbsent: aBlock
	^ (self includesKey: aKey)
		ifTrue: [ self basicAt: aKey ]
		ifFalse: [ aBlock value ]
!

at: aKey put: aValue
	^ self basicAt: aKey put: aValue
!

keys
	<return Object.keys(self)>
!

values
	<
		return self._keys().map(function(key){
			return self._at_(key);
		});
	>
! !

!HashedCollection methodsFor: 'adding/removing'!

removeKey: aKey ifAbsent: aBlock
	^ self
		at: aKey
		ifPresent: [ :removed | self basicDelete: aKey. removed ]
		ifAbsent: [ aBlock value ]
! !

!HashedCollection methodsFor: 'enumerating'!

keysDo: aBlock
	self keys do: aBlock
!

valuesDo: aBlock
	self values do: aBlock
! !

!HashedCollection methodsFor: 'testing'!

includesKey: aKey
	<return self.hasOwnProperty(aKey)>
! !

IndexableCollection subclass: #SequenceableCollection
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!SequenceableCollection commentStamp!
I am an IndexableCollection
with numeric indexes starting with 1.!

!SequenceableCollection methodsFor: 'accessing'!

allButFirst
	^ self copyFrom: 2 to: self size
!

allButLast
	^ self copyFrom: 1 to: self size - 1
!

atRandom
	^ self at: self size atRandom
!

first
	^ self at: 1
!

first: aNumber
	"Answer the first `aNumber` elements of the receiver.
	Raise an error if there are not enough elements in the receiver."

	self size < aNumber ifTrue: [ self error: 'Invalid number of elements' ].

	^ self copyFrom: 1 to: aNumber
!

fourth
	^ self at: 4
!

indexOf: anObject ifAbsent: aBlock
	<
		self = self._numericallyIndexable();
		for(var i=0; i < self.length; i++) {
			if($recv(self[i]).__eq(anObject)) {return i+1}
		};
		return aBlock._value();
	>
!

indexOf: anObject startingAt: start
	"Answer the index of the first occurence of anElement after start
	within the receiver. If the receiver does not contain anElement,
	answer 0."
	^ self indexOf: anObject startingAt: start ifAbsent: [ 0 ]
!

indexOf: anObject startingAt: start ifAbsent: aBlock
	<
		self = self._numericallyIndexable();
		for(var i=start - 1; i < self.length; i++){
			if($recv(self[i]).__eq(anObject)) {return i+1}
		}
		return aBlock._value();
	>
!

last
	^ self at: self size
!

last: aNumber
	"Answer the last aNumber elements of the receiver.
	Raise an error if there are not enough elements in the receiver."

	self size < aNumber ifTrue: [ self error: 'Invalid number of elements' ].

	^ self copyFrom: self size - aNumber + 1 to: self size
!

second
	^ self at: 2
!

third
	^ self at: 3
! !

!SequenceableCollection methodsFor: 'adding/removing'!

addLast: anObject
	self add: anObject
!

removeLast
	^ self remove: self last
! !

!SequenceableCollection methodsFor: 'comparing'!

= aCollection
	(self class = aCollection class and: [
		self size = aCollection size ]) ifFalse: [ ^ false ].
	self withIndexDo: [ :each :i |
				(aCollection at: i) = each ifFalse: [ ^ false ]].
	^ true
! !

!SequenceableCollection methodsFor: 'converting'!

reversed
	self subclassResponsibility
! !

!SequenceableCollection methodsFor: 'copying'!

copyFrom: anIndex to: anotherIndex
	| range newCollection |
	range := anIndex to: anotherIndex.
	newCollection := self class new: range size.
	range withIndexDo: [ :each :i |
		newCollection at: i put: (self at: each) ].
	^ newCollection
!

deepCopy
	| newCollection |
	newCollection := self class new: self size.
	self withIndexDo: [ :each :index |
		newCollection at: index put: each deepCopy ].
	^ newCollection
!

shallowCopy
	| newCollection |
	newCollection := self class new: self size.
	self withIndexDo: [ :each :index |
		newCollection at: index put: each ].
	^ newCollection
! !

!SequenceableCollection methodsFor: 'enumerating'!

detect: aBlock ifNone: anotherBlock
	<
		self = self._numericallyIndexable();
		for(var i = 0; i < self.length; i++)
			if(aBlock._value_(self[i]))
				return self[i];
		return anotherBlock._value();
	>
!

do: aBlock
	<
		self = self._numericallyIndexable();
		for(var i=0; i < self.length; i++) {
			aBlock._value_(self[i]);
		}
	>
!

with: anotherCollection do: aBlock
	<
		self = self._numericallyIndexable();
		anotherCollection = anotherCollection._numericallyIndexable();
		for(var i=0; i<self.length; i++) {
			aBlock._value_value_(self[i], anotherCollection[i]);
		}
	>
!

withIndexDo: aBlock
	<
		self = self._numericallyIndexable();
		for(var i=0; i < self.length; i++) {
			aBlock._value_value_(self[i], i+1);
		}
	>
! !

!SequenceableCollection methodsFor: 'private'!

numericallyIndexable
	"This is an internal converting message.
	It answeres a representation of the receiver
	that can use foo[i] in JavaScript code.
	
	It fixes IE8, where boxed String is unable
	to numerically index its characters,
	but primitive string can."
	
	self subclassResponsibility
! !

!SequenceableCollection methodsFor: 'streaming'!

newStream
	^ self streamClass on: self
!

readStream
	"For Pharo compatibility"
	
	^ self stream
!

stream
	^ self newStream
!

streamClass
	^ self class streamClass
!

writeStream
	"For Pharo compatibility"
	
	^ self stream
! !

!SequenceableCollection methodsFor: 'testing'!

beginsWith: prefix
	self size < prefix size ifTrue: [ ^ false ].
	^ (self first: prefix size) = prefix
!

endsWith: suffix
	self size < suffix size ifTrue: [ ^ false ].
	^ (self last: suffix size) = suffix
!

includes: anObject
	^ (self indexOf: anObject ifAbsent: [ nil ]) notNil
! !

!SequenceableCollection class methodsFor: 'accessing'!

streamClass
		^ Stream
! !

!SequenceableCollection class methodsFor: 'streaming'!

streamContents: aBlock
	| stream |
	stream := (self streamClass on: self new).
	aBlock value: stream.
	^ stream contents
! !

SequenceableCollection subclass: #Array
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!Array commentStamp!
I represent a collection of objects ordered by the collector. The size of arrays is dynamic.

I am directly mapped to JavaScript Number.

*Note* In Amber, `OrderedCollection` is an alias for `Array`.!

!Array methodsFor: 'accessing'!

at: anIndex ifAbsent: aBlock
	<
		return anIndex >>= 1 && anIndex <= self.length
			? self[anIndex - 1]
			: aBlock._value()
	>
!

at: anIndex ifPresent: aBlock ifAbsent: anotherBlock
	<
		return anIndex >>= 1 && anIndex <= self.length
			? aBlock._value_(self[anIndex - 1])
			: anotherBlock._value()
	>
!

at: anIndex put: anObject
	<return self[anIndex - 1] = anObject>
!

size
	<return self.length>
! !

!Array methodsFor: 'adding/removing'!

add: anObject
	<self.push(anObject); return anObject;>
!

addFirst: anObject
	<self.unshift(anObject); return anObject;>
!

remove: anObject ifAbsent: aBlock
	| index |
	index := self indexOf: anObject ifAbsent: [ 0 ].
	^ index = 0
		ifFalse: [ self removeIndex: index. anObject ]
		ifTrue: [ aBlock value ]
!

removeAll
	<self.length = 0>
!

removeFrom: aNumber to: anotherNumber
	<self.splice(aNumber -1, anotherNumber - aNumber + 1)>
!

removeIndex: anInteger
	<self.splice(anInteger - 1, 1)>
!

removeLast
	<return self.pop();>
! !

!Array methodsFor: 'converting'!

asJavascript
	^ '[', ((self collect: [:each | each asJavascript ]) join: ', '), ']'
!

reversed
	<return self._copy().reverse()>
! !

!Array methodsFor: 'enumerating'!

collect: aBlock
	"Optimized version"
	
	<return self.map(function(each) {return aBlock._value_(each)})>
!

join: aString
	<return self.join(aString)>
!

select: aBlock
	"Optimized version"
	
	<
		var result = self.klass._new();
		for(var i=0; i<self.length; i++) {
			if(aBlock._value_(self[i])) {
				result.push(self[i]);
			}
		}
		return result;
	>
!

sort
	^ self sort: [ :a :b | a < b ]
!

sort: aBlock
	<
		return self.sort(function(a, b) {
			if(aBlock._value_value_(a,b)) {return -1} else {return 1}
		})
	>
!

sorted
	^ self copy sort
!

sorted: aBlock
	^ self copy sort: aBlock
! !

!Array methodsFor: 'printing'!

printOn: aStream
	super printOn: aStream.
	
	aStream nextPutAll: ' ('.
	self 
		do: [ :each | each printOn: aStream ]
		separatedBy: [ aStream nextPutAll: ' ' ].
	aStream nextPutAll: ')'
! !

!Array methodsFor: 'private'!

numericallyIndexable
	^ self
! !

!Array class methodsFor: 'instance creation'!

new: anInteger
	<return new Array(anInteger)>
!

with: anObject
		^ (self new: 1)
		at: 1 put: anObject;
		yourself
!

with: anObject with: anObject2
		^ (self new: 2)
		at: 1 put: anObject;
		at: 2 put: anObject2;
		yourself
!

with: anObject with: anObject2 with: anObject3
		^ (self new: 3)
		at: 1 put: anObject;
		at: 2 put: anObject2;
		at: 3 put: anObject3;
		yourself
!

withAll: aCollection
	| instance index |
	index := 1.
	instance := self new: aCollection size.
	aCollection do: [ :each |
		instance at: index put: each.
		index := index + 1 ].
	^ instance
! !

SequenceableCollection subclass: #CharacterArray
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!CharacterArray commentStamp!
I am the abstract superclass of string-like collections.!

!CharacterArray methodsFor: 'accessing'!

at: anIndex put: anObject
	self errorReadOnly
! !

!CharacterArray methodsFor: 'adding/removing'!

add: anObject
	self errorReadOnly
!

remove: anObject
	self errorReadOnly
! !

!CharacterArray methodsFor: 'converting'!

asLowercase
	^ self class fromString: self asString asLowercase
!

asNumber
	^ self asString asNumber
!

asString
	^ self subclassResponsibility
!

asSymbol
	^ self asString
!

asUppercase
	^ self class fromString: self asString asUppercase
! !

!CharacterArray methodsFor: 'copying'!

, aString
	^ self asString, aString asString
! !

!CharacterArray methodsFor: 'error handling'!

errorReadOnly
	self error: 'Object is read-only'
! !

!CharacterArray methodsFor: 'printing'!

printOn: aStream
	self asString printOn: aStream
! !

!CharacterArray methodsFor: 'streaming'!

putOn: aStream
	aStream nextPutString: self
! !

!CharacterArray class methodsFor: 'instance creation'!

fromString: aString
	self subclassResponsibility
! !

CharacterArray subclass: #String
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!String commentStamp!
I am an indexed collection of Characters. Unlike most Smalltalk dialects, Amber doesn't provide the Character class. Instead, elements of a String are single character strings.

String inherits many useful methods from its hierarchy, such as
	`Collection >> #,`!

!String methodsFor: 'accessing'!

asciiValue
	<return self.charCodeAt(0);>
!

at: anIndex ifAbsent: aBlock
	<return String(self)[anIndex - 1] || aBlock._value()>
!

at: anIndex ifPresent: aBlock ifAbsent: anotherBlock
	<
		var result = String(self)[anIndex - 1];
		return result ? aBlock._value_(result) : anotherBlock._value();
	>
!

charCodeAt: anInteger
	<return self.charCodeAt(anInteger - 1)>
!

identityHash
	^ self, 's'
!

size
	<return self.length>
! !

!String methodsFor: 'comparing'!

< aString
	<return String(self) < aString._asString()>
!

<= aString
	<return String(self) <= aString._asString()>
!

= aString
	<
		return aString !!= null &&
			typeof aString._isString === "function" &&
			aString._isString() &&
			String(self) === String(aString)
	>
!

== aString
	^ self = aString
!

> aString
	<return String(self) >> aString._asString()>
!

>= aString
	<return String(self) >>= aString._asString()>
! !

!String methodsFor: 'converting'!

asJSON
	^ self
!

asJavaScriptMethodName
	<return $core.st2js(self)>
!

asJavascript
	<
		if(self.search(/^[a-zA-Z0-9_:.$ ]*$/) == -1)
			return "\"" + self.replace(/[\x00-\x1f"\\\x7f-\x9f]/g, function(ch){var c=ch.charCodeAt(0);return "\\x"+("0"+c.toString(16)).slice(-2)}) + "\"";
		else
			return "\"" + self + "\"";
	>
!

asLowercase
	<return self.toLowerCase()>
!

asMutator
	"Answer a setter selector. For example,
	#name asMutator returns #name:"

	self last = ':' ifFalse: [  ^ self, ':' ].
	^ self
!

asNumber
	<return Number(self)>
!

asRegexp
	^ RegularExpression fromString: self
!

asString
	^ self
!

asSymbol
	^ self
!

asUppercase
	<return self.toUpperCase()>
!

capitalized
	^ self isEmpty
		ifTrue: [ self ]
		ifFalse: [ self first asUppercase, self allButFirst ]
!

crlfSanitized
	^ self lines join: String lf
!

escaped
	<return escape(self)>
!

reversed
	<return self.split("").reverse().join("")>
!

unescaped
	<return unescape(self)>
!

uriComponentDecoded
	<return decodeURIComponent(self)>
!

uriComponentEncoded
	<return encodeURIComponent(self)>
!

uriDecoded
	<return decodeURI(self)>
!

uriEncoded
	<return encodeURI(self)>
! !

!String methodsFor: 'copying'!

, aString
	<return String(self) + aString>
!

copyFrom: anIndex to: anotherIndex
	<return self.substring(anIndex - 1, anotherIndex)>
!

deepCopy
	^ self shallowCopy
!

shallowCopy
	^ self class fromString: self
! !

!String methodsFor: 'evaluating'!

value: anObject 
	^ anObject perform: self
! !

!String methodsFor: 'printing'!

printNl
	<console.log(self)>
!

printOn: aStream
	aStream 
		nextPutAll: '''';
		nextPutAll: self;
		nextPutAll: ''''
! !

!String methodsFor: 'private'!

numericallyIndexable
	<return String(self)>
! !

!String methodsFor: 'regular expressions'!

match: aRegexp
	<return self.search(aRegexp) !!= -1>
!

matchesOf: aRegularExpression
	<return self.match(aRegularExpression)>
!

replace: aString with: anotherString
	^ self replaceRegexp: (RegularExpression fromString: aString flag: 'g') with: anotherString
!

replaceRegexp: aRegexp with: aString
	<return self.replace(aRegexp, aString)>
!

trimBoth
	^ self trimBoth: '\s'
!

trimBoth: separators
	^ (self trimLeft: separators) trimRight: separators
!

trimLeft
	^ self trimLeft: '\s'
!

trimLeft: separators
	^ self replaceRegexp: (RegularExpression fromString: '^[', separators, ']+' flag: 'g') with: ''
!

trimRight
	^ self trimRight: '\s'
!

trimRight: separators
	^ self replaceRegexp: (RegularExpression fromString: '[', separators, ']+$' flag: 'g') with: ''
! !

!String methodsFor: 'split join'!

join: aCollection
	^ String
		streamContents: [ :stream | aCollection
				do: [ :each | stream nextPutAll: each asString ]
				separatedBy: [ stream nextPutAll: self ]]
!

lineIndicesDo: aBlock
	"execute aBlock with 3 arguments for each line:
	- start index of line
	- end index of line without line delimiter
	- end index of line including line delimiter(s) CR, LF or CRLF"
	
	| cr lf start sz nextLF nextCR |
	start := 1.
	sz := self size.
	cr := String cr.
	nextCR := self indexOf: cr startingAt: 1.
	lf := String lf.
	nextLF := self indexOf: lf startingAt: 1.
	[ start <= sz ] whileTrue: [ 
		(nextLF = 0 and: [ nextCR = 0 ])
			ifTrue: [ "No more CR, nor LF, the string is over"
					aBlock value: start value: sz value: sz.
					^ self ].
		(nextCR = 0 or: [ 0 < nextLF and: [ nextLF < nextCR ] ])
			ifTrue: [ "Found a LF"
					aBlock value: start value: nextLF - 1 value: nextLF.
					start := 1 + nextLF.
					nextLF := self indexOf: lf startingAt: start ]
			ifFalse: [ 1 + nextCR = nextLF
				ifTrue: [ "Found a CR-LF pair"
					aBlock value: start value: nextCR - 1 value: nextLF.
					start := 1 + nextLF.
					nextCR := self indexOf: cr startingAt: start.
					nextLF := self indexOf: lf startingAt: start ]
				ifFalse: [ "Found a CR"
					aBlock value: start value: nextCR - 1 value: nextCR.
					start := 1 + nextCR.
					nextCR := self indexOf: cr startingAt: start ] ]]
!

lineNumber: anIndex
	"Answer a string containing the characters in the given line number."

	| lineCount |
	lineCount := 0.
	self lineIndicesDo: [ :start :endWithoutDelimiters :end |
		(lineCount := lineCount + 1) = anIndex ifTrue: [ ^ self copyFrom: start to: endWithoutDelimiters ]].
	^ nil
!

lines
	"Answer an array of lines composing this receiver without the line ending delimiters."

	| lines |
	lines := Array new.
	self linesDo: [ :aLine | lines add: aLine ].
	^ lines
!

linesDo: aBlock
	"Execute aBlock with each line in this string. The terminating line
	delimiters CR, LF or CRLF pairs are not included in what is passed to aBlock"

	self lineIndicesDo: [ :start :endWithoutDelimiters :end |
		aBlock value: (self copyFrom: start to: endWithoutDelimiters) ]
!

subStrings: aString
	^ self tokenize: aString
!

tokenize: aString
	<return self.split(aString)>
! !

!String methodsFor: 'testing'!

includesSubString: subString
	<return self.indexOf(subString) !!= -1>
!

isCapitalized
	^ self first asUppercase == self first
!

isImmutable
	^ true
!

isString
	^ true
!

isVowel
	"Answer true if the receiver is a one character string containing a voyel"
	
	^ self size = 1 and: [ 'aeiou' includes: self asLowercase ]
! !

!String class methodsFor: 'accessing'!

cr
	<return '\r'>
!

crlf
	<return '\r\n'>
!

esc
	^ self fromCharCode: 27
!

lf
	<return '\n'>
!

space
	<return ' '>
!

streamClass
		^ StringStream
!

tab
	<return '\t'>
! !

!String class methodsFor: 'instance creation'!

fromCharCode: anInteger
	<return String.fromCharCode(anInteger)>
!

fromString: aString
		<return String(aString)>
!

value: aUTFCharCode

	<return String.fromCharCode(aUTFCharCode);>
! !

!String class methodsFor: 'random'!

random
	"Returns random alphanumeric string beginning with letter"
	<return (Math.random()*(22/32)+(10/32)).toString(32).slice(2);>
!

randomNotIn: aString
	| result |
	[ result := self random. aString includesSubString: result ] whileTrue.
	^ result
! !

Collection subclass: #Set
	instanceVariableNames: 'defaultBucket slowBucketStores fastBuckets size'
	package: 'Kernel-Collections'!
!Set commentStamp!
I represent an unordered set of objects without duplicates.

## Implementation notes

I put elements into different stores based on their type.
The goal is to store some elements into native JS object property names to be fast.

If an unboxed element has typeof 'string', 'boolean' or 'number', or an element is nil, null or undefined,
I store it as a property name in an empty (== Object.create(null)) JS object, different for each type
(for simplicity, nil/null/undefined is treated as one and included with the two booleans).

If element happen to be an object, I try to store them in `ArrayBucketStore`. I have two of them by default,
one hashed using the Smalltalk class name, the other one using the JS constructor name. It is possible to have more or less
instances of `ArrayBucketStores`, see `#initializeSlowBucketStores`.

As a last resort, if none of the `ArrayBucketStore` instances can find a suitable bucket, the `defaultBucket` is used,
which is an `Array`.!

!Set methodsFor: 'accessing'!

size
	^ size
! !

!Set methodsFor: 'adding/removing'!

add: anObject
	| bucket |
	bucket := self bucketsOfElement: anObject.
	^ bucket second
		ifNil: [
			| object slowBucket |
			object := bucket first.
			slowBucket := bucket third.
			slowBucket 
				indexOf: object 
				ifAbsent: [ 
					slowBucket add: object. 
					size := size + 1 ].
			object ]
		ifNotNil: [ :primitiveBucket | 
			self 
				add: bucket first 
				in: primitiveBucket ]
!

remove: anObject ifAbsent: aBlock
	| bucket |
	bucket := self bucketsOfElement: anObject.
	^ bucket second
		ifNil: [ bucket third remove: bucket first ifAbsent: [ ^aBlock value ]. size := size - 1 ]
		ifNotNil: [ :primitiveBucket | self remove: bucket first in: primitiveBucket ]
!

removeAll
	<
		self['@fastBuckets'] = {
			'boolean': { store: Object.create(null), fn: function (x) { return {'true': true, 'false': false, 'null': null}[x]; } },
			'number': { store: Object.create(null), fn: Number },
			'string': { store: Object.create(null) }
		};
		self['@slowBucketStores'].forEach(function (x) { x._removeAll(); });
		self['@defaultBucket']._removeAll();
		self['@size'] = 0;
	>
! !

!Set methodsFor: 'comparing'!

= aCollection
	self class = aCollection class ifFalse: [ ^ false ].
	self size = aCollection size ifFalse: [ ^ false ].
	self do: [ :each | (aCollection includes: each) ifFalse: [ ^ false ] ].
	^ true
! !

!Set methodsFor: 'enumerating'!

collect: aBlock
	| collection |
	collection := self class new.
	self do: [ :each | collection add: (aBlock value: each) ].
	^ collection
!

detect: aBlock ifNone: anotherBlock
	self do: [ :each | (aBlock value: each) ifTrue: [ ^each ] ].
	^ anotherBlock value
!

do: aBlock
	<
		var el, keys, i;
		el = self['@fastBuckets'];
		keys = Object.keys(el);
		for (i = 0; i < keys.length; ++i) {
			var fastBucket = el[keys[i]], fn = fastBucket.fn, store = Object.keys(fastBucket.store);
			if (fn) { for (var j = 0; j < store.length; ++j) { aBlock._value_(fn(store[j])); } }
			else { store._do_(aBlock); }
		}
		el = self['@slowBucketStores'];
		for (i = 0; i < el.length; ++i) { el[i]._do_(aBlock); }
		self['@defaultBucket']._do_(aBlock);
	>
!

select: aBlock
	| collection |
	collection := self class new.
	self do: [ :each |
		(aBlock value: each) ifTrue: [
			collection add: each ] ].
	^ collection
! !

!Set methodsFor: 'initialization'!

initialize
	super initialize.
	
	defaultBucket := #().
	self
		initializeSlowBucketStores;
		removeAll
!

initializeSlowBucketStores
	slowBucketStores := {
		ArrayBucketStore hashBlock: [ :x | self classNameOf: x ].
		ArrayBucketStore hashBlock: [ :x | self jsConstructorNameOf: x ]
	}
! !

!Set methodsFor: 'printing'!

printOn: aStream
	super printOn: aStream.
	
	aStream nextPutAll: ' ('.
	self 
		do: [ :each | each printOn: aStream ]
		separatedBy: [ aStream nextPutAll: ' ' ].
	aStream nextPutAll: ')'
! !

!Set methodsFor: 'private'!

add: anObject in: anotherObject
	<
		if (anObject in anotherObject.store) { return false; }
		self['@size']++;
		return anotherObject.store[anObject] = true;
	>
!

bucketsOfElement: anObject
	"Find the appropriate bucket for `anObject`.
	For optimization purposes, directly answer an array with: 
	- the object to be store
	- the primitive bucket
	- the slow bucket"
	
	<
		var type, bucket, prim = anObject == null ? (anObject = nil) : anObject.valueOf();
		if ((type = typeof prim) === "object") {
			if (anObject !!== nil) {
				bucket = null;
				self['@slowBucketStores'].some(function (store) {
					return bucket = store._bucketOfElement_(anObject);
				});
				return [ anObject, null, bucket || self['@defaultBucket'] ];
			}
			
			// include nil to well-known objects under 'boolean' fastBucket
			prim = null;
			type = 'boolean';
		}
		return [ prim, self['@fastBuckets'][type] ];
	>
!

classNameOf: anObject
	"Answer the class name of `anObject`, or `undefined` 
	if `anObject` is not an Smalltalk object"
	
	<return anObject.klass && anObject.klass.className>
!

includes: anObject in: anotherObject
	<return anObject in anotherObject.store>
!

jsConstructorNameOf: anObject
	<return anObject.constructor && anObject.constructor.name>
!

remove: anObject in: anotherObject
	<if (delete anotherObject.store[anObject]) self['@size']-->
! !

!Set methodsFor: 'testing'!

includes: anObject
	| bucket |
	bucket := self bucketsOfElement: anObject.
	^ bucket second
		ifNil: [ bucket third includes: bucket first ]
		ifNotNil: [ :primitiveBucket | self includes: bucket first in: primitiveBucket ]
! !

Object subclass: #Queue
	instanceVariableNames: 'read readIndex write'
	package: 'Kernel-Collections'!
!Queue commentStamp!
I am a one-sided queue.

## Usage

Use `#nextPut:` to add items to the queue.
Use `#next` or `#nextIfAbsent:` to get (and remove) the next item in the queue.

## Implementation notes

A Queue uses two OrderedCollections inside,
`read` is at the front, is not modified and only read using `readIndex`.
`write` is at the back and is appended new items.
When `read` is exhausted, `write` is promoted to `read` and new `write` is created.

As a consequence, no data moving is done by me, write appending may do data moving
when growing `write`, but this is left to engine to implement as good as it chooses to.!

!Queue methodsFor: 'accessing'!

next
	^ self nextIfAbsent: [ self error: 'Cannot read from empty Queue.' ]
!

nextIfAbsent: aBlock
	| result |
	result := read at: readIndex ifAbsent: [
		write isEmpty ifTrue: [
			readIndex > 1 ifTrue: [ read := #(). readIndex := 1 ].
			^ aBlock value ].
		read := write.
		readIndex := 1.
		write := OrderedCollection new.
		read first ].
	read at: readIndex put: nil.
	readIndex := readIndex + 1.
	^ result
!

nextPut: anObject
	write add: anObject
! !

!Queue methodsFor: 'initialization'!

initialize
	super initialize.
	read := OrderedCollection new.
	write := OrderedCollection new.
	readIndex := 1
! !

Object subclass: #RegularExpression
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!RegularExpression commentStamp!
I represent a regular expression object. My instances are JavaScript `RegExp` object.!

!RegularExpression methodsFor: 'evaluating'!

compile: aString
	<return self.compile(aString)>
!

exec: aString
	<return self.exec(aString) || nil>
!

test: aString
	<return self.test(aString)>
! !

!RegularExpression class methodsFor: 'instance creation'!

fromString: aString
		^ self fromString: aString flag: ''
!

fromString: aString flag: anotherString
	<return new RegExp(aString, anotherString)>
! !

Object subclass: #Stream
	instanceVariableNames: 'collection position streamSize'
	package: 'Kernel-Collections'!
!Stream commentStamp!
I represent an accessor for a sequence of objects. This sequence is referred to as my "contents".
My instances are read/write streams to the contents sequence collection.!

!Stream methodsFor: 'accessing'!

collection
	^ collection
!

contents
	^ self collection
		copyFrom: 1
		to: self streamSize
!

position
	^ position ifNil: [ position := 0 ]
!

position: anInteger
	position := anInteger
!

setCollection: aCollection
	collection := aCollection
!

setStreamSize: anInteger
	streamSize := anInteger
!

size
	^ self streamSize
!

streamSize
	^ streamSize
! !

!Stream methodsFor: 'actions'!

close
!

flush
!

reset
	self position: 0
!

resetContents
	self reset.
	self setStreamSize: 0
! !

!Stream methodsFor: 'enumerating'!

do: aBlock
	[ self atEnd ] whileFalse: [ aBlock value: self next ]
! !

!Stream methodsFor: 'positioning'!

setToEnd
	self position: self size
!

skip: anInteger
	self position: ((self position + anInteger) min: self size max: 0)
! !

!Stream methodsFor: 'reading'!

next
	^ self atEnd
		ifTrue: [ nil ]
		ifFalse: [
			self position: self position + 1.
			collection at: self position ]
!

next: anInteger
	| tempCollection |
	tempCollection := self collection class new.
	anInteger timesRepeat: [
		self atEnd ifFalse: [
		tempCollection add: self next ]].
	^ tempCollection
!

peek
	^ self atEnd ifFalse: [
		self collection at: self position + 1 ]
! !

!Stream methodsFor: 'testing'!

atEnd
	^ self position = self size
!

atStart
	^ self position = 0
!

isEmpty
	^ self size = 0
! !

!Stream methodsFor: 'writing'!

<< anObject
	self write: anObject
!

nextPut: anObject
	self position: self position + 1.
	self collection at: self position put: anObject.
	self setStreamSize: (self streamSize max: self position)
!

nextPutAll: aCollection
	aCollection do: [ :each |
		self nextPut: each ]
!

nextPutString: aString
	self nextPut: aString
!

write: anObject
	anObject putOn: self
! !

!Stream class methodsFor: 'instance creation'!

on: aCollection
		^ self new
		setCollection: aCollection;
		setStreamSize: aCollection size;
		yourself
! !

Stream subclass: #StringStream
	instanceVariableNames: ''
	package: 'Kernel-Collections'!
!StringStream commentStamp!
I am a Stream specific to `String` objects.!

!StringStream methodsFor: 'reading'!

next: anInteger
	| tempCollection |
	tempCollection := self collection class new.
	anInteger timesRepeat: [
		self atEnd ifFalse: [
		tempCollection := tempCollection, self next ]].
	^ tempCollection
! !

!StringStream methodsFor: 'writing'!

cr
	^ self nextPutAll: String cr
!

crlf
	^ self nextPutAll: String crlf
!

lf
	^ self nextPutAll: String lf
!

nextPut: aString
	self nextPutAll: aString
!

nextPutAll: aString
	| pre post |
	self atEnd ifTrue: [ self setCollection: self collection, aString ] ifFalse: [
		pre := self collection copyFrom: 1 to: self position.
		post := self collection copyFrom: (self position + 1 + aString size) to: self collection size.
		self setCollection: pre, aString, post
	].
	self position: self position + aString size.
	self setStreamSize: (self streamSize max: self position)
!

nextPutString: aString
	self nextPutAll: aString
!

space
	self nextPut: ' '
!

tab
	^ self nextPutAll: String tab
! !