Google

dictnary Specification Sheet

Portable Object Compiler (c) 1997,98. All Rights Reserved.

Dictionary

Inherits from: Object

Class Description

Dictionaries (instances of the Dictionary class) are key-value tables : to each key object, a value object is associated. The key can then be used to access the corresponding value. There are a few special provisions for tables with String instances as keys.

Method types

Creation

Interrogation

Comparing

Indexed Access

Adding and Removing

Blocks

Printing

Methods

new

+new
Returns a new empty dictionary.

copy

-copy
Returns a new copy of the dictionary.

deepCopy

-deepCopy
Returns a new copy of the dictionary. The members in the new dictionary are deep copies of the members in the original dictionary.

emptyYourself

-emptyYourself
Removes all the keys and values of the dictionary (without freeing them). Returns the receiver.

freeContents

-freeContents
This method is, in the case of the Dictionary class, equivalent to emptyYourself. Note that for the sake of Stepstone ICpak101 compatibility, this method does not free keys and values. Use freeAll for that.

freeAll

-freeAll
This method frees all the keys and values in the dictionary, without freeing the dictionary itself. Returns the dictionary.

Note: This method is ObjectPak specific.

free

-free
Frees the dictionary, but not its contents. Returns nil. Do :

aDic = [[aDic freeAll] free];
if you want to free the dictionary and its contents.

size

- (unsigned)size
Returns the number of key-value associations in the dictionary.

isEmpty

- (BOOL)isEmpty
Whether the number of associations in the dictionary is equal to zero.

includesKey:

- (BOOL)includesKey:aKey
Returns YES if there is an association with key matching aKey.

hash

- (unsigned)hash
Returns a hash value based on the receiver's address and the results of sending the hash message to the contents.

isEqual:

- (BOOL)isEqual:aDic
Returns YES if aDic is a dictionary, and if its keys and values respond affirmatively to the message isEqual: when compared to the corresponding objects of the receiver's contents.

atKey:

-atKey:aKey
Returns the value of the association matching aKey. Returns nil if the association is not found.

atKey:ifAbsent:

-atKey:aKeyifAbsent:exceptionBlock
Returns the value of the association matching aKey. Evaluates exceptionBlock and returns its return value, if the association is not found.

atKeySTR:

-atKeySTR:(STR)strKey
Returns the value of the association matching strKey. Returns nil if the association is not found.

atKey:put:

-atKey:aKeyput:anObject
Associates aKey to anObject. Adds the objects to the dictionary. If aKey was already in the dictionary, makes anObject the value for this key and returns the old value. Otherwise returns nil.

atKeySTR:put:

-atKeySTR:(STR)strKeyput:anObject
Associates strKey to anObject. Adds the objects to the dictionary. If strKey was already in the dictionary, makes anObject the value for this key and returns the old value. Otherwise returns nil.

eachKey

-eachKey
Returns a sequence of the key objects in the dictionary.

keys = [aDic eachKey];
while ((aKey = [aSeq next])) {
    /* do something */
}
keys = [keys free];
See also: eachValue

eachValue

-eachValue
Returns a sequence of the value objects in the dictionary.

keys   = [aDic eachKey];
values = [aDic eachValue];
while ((aKey = [aSeq next])) {
    aValue = [values next];
    /* do something */
}
keys   = [keys free];
values = [values free];
See also: eachKey

removeKey:

-removeKey:key
Remove key from the receiver and return value for given key. If key is not in the receiver, notify an error.

removeKey:ifAbsent:

-removeKey:keyifAbsent:aBlock
Remove key (and its associated value) from the receiver. If key is not in the receiver, answers the result of evaluating aBlock. Otherwise, answers the value externally named by key.

keysDo:

-keysDo:aBlock
The keysDo: message iterates through all the Dictionary elements, running a one-argument block of code specified by the aBlock argument with the argument set to the key of each assocation.

printOn:

-printOn:(IOD)aFile
Prints a comma separated list of the key-value pairs by sending each individual object a printOn: message. Returns the receiver.