Topic: object modification

topics > computer science > Group: data

immutable files and data
object-oriented objects
object transformation language
referential transparency
structure transformation languages
value as an object


Operations on data objects may modify the objects instead of replacing their values. For instance integers can be incremented or decremented. Modification is dependent on the object's current value. This makes the object a state machine and prevents referential transparency. If the object is a machine's store then modification is identified with program execution. (cbb 5/80)
Subtopic: updating as recreating environment up

Quote: updating a location is the same as producing a new store which is a slight modification of the original one [»straC3_1973]
QuoteRef: hehnEC7_1975 ;;63 L[5]<- 8 means L<-# replace 5 by 8 i.e. L[5] now stands for a different value

Subtopic: values vs. objects up

Quote: programming languages treat atomic data types as values and compound ones as objects; causes unnecessary confusion [»maclBJ12_1982]

Subtopic: incremental operations up

Quote: C includes pre- and post-increment of a variable [»ritcDM7_1978c]
Quote: implement binary operators of complicated types with assignment operators; e.g., implement matrix addition in terms of '+=' [»stroB_1991]

Subtopic: update by add/delete up

Quote: modify a relation tuple by adding the new one and deleting the old [»earlJ4_1974, OK]
QuoteRef: seedH_1971 ;;123 replacement by operation zero result and add operand

Subtopic: read-only up

Quote: a 'const' member function can read but not write its object [»stroB_1991]

Subtopic: read-only plus maintenance modifications up

Quote: a member function can "cast away const" if the object is modified but it appears constant to its users; e.g., caching values, maintaining statistics, updating use counts

Subtopic: combining editing with compiling/running up

Quote: Self allows modification at any time; most interface builders separate editing from running the interface

Related Topics up

Topic: immutable files and data (59 items)
Topic: object-oriented objects (39 items)
Topic: object transformation language (10 items)
Topic: referential transparency (26 items)
Topic: structure transformation languages (7 items)
Topic: value as an object
(29 items)

Updated barberCB 9/04
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