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Topic: referential transparency
topics >
philosophy >
definition
Topic:
expression language
Topic:
formal methods and languages
Topic:
functional programming
Topic:
meaning vs. reference
Topic:
names as rigid designators
Topic:
number representation
Topic:
object and value equivalence
Topic:
object modification
Topic:
proper names
Topic:
reduction languages
Topic:
reductionism
Topic:
restricted and extended types
Topic:
safe use of pointers
Topic:
uniform reference to data
Topic:
value as an abstraction
Topic:
value as an object
Topic:
weak vs. strong type checking
Summary
With referential transparency, values and expressions are the same. There are no side-effects to executing an expression. The value of an expression is independent of its context. This allows expressions to be reduced to a value. Quine developed the idea. (cbb 1/90)
Subtopic: syntactic analysis
Quote: referential transparency means that the value of an expression is determined by the values of its sub-expressions [»straC8_1967] Quote: referential transparency: value and expression are equivalent in any position [»stoyJ_1977, OK] Quote: referential transparency: expression can be replaced with another expression of same value [»tennRD8_1976, OK] Quote: referential transparency--the result of a function is solely dependent on its arguments; a pure functional language [»plasR6_1999] Quote: in a reduction language can reduce any subexpression without changing its value [»backJ_1972] Quote: reduce an expression by replacing a subexpression by its value; reduction language Quote: variables in mathematics are names that do not vary; e.g., x is the same x in 3x^2+2x+17; consequence of referential transparency [»straC8_1967]
Subtopic: natural language
Quote: the symbol string 1+5 is not 6 in all circumstances, for example 21+52; requires syntactic analysis
Subtopic: values vs. objects
Quote: if a language contains intension adverbs (necessarily) then interchanging equivalent predicates can demonstrate cognitive synonymy; analytic already [»quinWV1_1951] Quote: in an extensional language can interchange equivalent extensional predicates but the agreement may be accidental and not due to meaning
Subtopic: substitutivity
Quote: values are referentially transparent while objects are referentially opaque; i.e., values do not have side effects and identical values may be substituted freely [»taivA4_1993]
Subtopic: recursive understanding
Quote: data type abstraction allows one variable to be substituted for another without making the program illegal or meaningless [»parnDL3_1976] Quote: a term is a name of an entity if identical entities may be substituted; Frege [»quinWV_1950] Quote: a restricted type matches the base type's structure and may be used everywhere the base type is used [»simeJ1_2003] Quote: indiscernibility of identicals--identicals may be substituted in any true statement [»quinWV_1947]
Subtopic: unique reference
Quote: understand X+Y by recursively understanding each part independently; manifest structure, clear meaning and purpose Quote: pidgins are semantically transparent with one form for one meaning; e.g., two words to specify gender of all species [»sebbM_1997] Quote: a concept is the entity which a predicate means; the meaning of a complex name depends on the meaning, not the sense, of its parts [»dummM_1967]
Subtopic: functional language
Quote: CLEAN maintains referential transparency of mutable arguments by guaranteeing unique references; e.g., via a copy Quote: SafeTSA is compact, type-safe mobile code based on static single assignment; safe by construction with referential integrity, type separation, and type check elimination [»ammeW6_2001]
Subtopic: databases
Quote: complete language <=> fixed points of a semantic function are the values of its expressions [»backJ_1973, OK] Quote: a functional language needs substitutivity of equivalence for mathematical proofs about evaluations Quote: in FAD, the name for an item expression can always be replaced by its definition [»martJJ_1980]
Subtopic: failure of substitutivity
Quote: Codd developed relational databases to solve data-maintenance abnormalities due to failures in referential transparency [»cobbRH11_1990]
Quote: substitutivity fails for Giorgione = Barbarelli in "Giorgione was so-called because of his size" Quote: the assignment statement undoes referential transparency and identity; how much of mathematics can survive?
[»straC8_1967]
Topic: definition (17 items)
Topic: expression language (14 items)
Topic: formal methods and languages (53 items)
Topic: functional programming (45 items)
Topic: meaning vs. reference (49 items)
Topic: names as rigid designators (43 items)
Topic: number representation (16 items)
Topic: object and value equivalence (60 items)
Topic: object modification (10 items)
Topic: proper names (35 items)
Topic: reduction languages (17 items)
Topic: reductionism (51 items)
Topic: restricted and extended types (35 items)
Topic: safe use of pointers (102 items)
Topic: uniform reference to data (34 items)
Topic: value as an abstraction (25 items)
Topic: value as an object (29 items)
Topic: weak vs. strong type checking
(42 items)