Term
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Definition
| any entity that exists during computation |
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Term
| Why can't all values be stored? |
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Definition
| space limitations in memory |
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Term
|
Definition
| a classification for identifying data |
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Term
| What are the 3 kinds of types? |
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Definition
| primitive, composite, recursive |
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Term
| How can one represent composite types in Java? |
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Definition
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Term
| What is a primitive type? |
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Definition
one whose values are atomic and therefore
cannot be decomposed into simpler values |
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Term
| How and why do values of primitive types vary from one machine to another? |
|
Definition
| different word sizes in different machines, instruction set |
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Term
| What is an enumerated type? |
|
Definition
a user-defined (usually ordinal) primitive
type where all possible values have been provided (or enumerated) |
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Term
|
Definition
a type where all possible values (except the
first and last ones) have a unique predecessor and successor |
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Term
| What primitive types found in most languages are not also ordinal types? Why? |
|
Definition
| Real values, because there are infinite # of them and cant be enumerated |
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Term
| What is the cardinality of a type? |
|
Definition
the number of distinct or
unique values in the set |
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Term
| What is a composite type? |
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Definition
| a type whose values are composed or structured from simpler values |
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Term
| What is a cartesian product type? |
|
Definition
the pairing of two (or more) (possibly
different) values where the order is significant |
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Term
How would we define (formally and in Pascal) the type of an individual entry (value)
in a phone book consisting of a first name, last name, and a phone number? What is this new type's cardinality? |
|
Definition
Cartisian Product
String x String x Integer |
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Term
| How does one implement a cartesian product type in Java? |
|
Definition
| a method with instance variables |
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Term
| What are homogeneous tuples? 0-tuples? |
|
Definition
all tuple components are chosen from
the same set
homogeneous tuple with no components |
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Term
| What is a disjoint union type? |
|
Definition
value is chosen from either of two (or
more) (usually different) types |
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Term
| What are tags in disjoint union types? |
|
Definition
| considered part of a disjoint union value |
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Term
How would we define (formally and in Pascal) a disjoint union type with 3 fields
of type integer, real, and string? What is the cardinality of this new type? |
|
Definition
Integer + Real + String
#Integer + #Real + #String |
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Term
| What is the problem with how disjoint unions types are implemented in Pascal? |
|
Definition
| tags are essentially ignored in pascal so it doesnt do the proper checking |
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Term
| Is a disjoint union the same thing as set union? Why or why not? |
|
Definition
| no because there are tags associated with both the values that are linked by the disjoint union |
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Term
|
Definition
a mathematical relation such that each element of a
given set (type) is associated with an element of another set |
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Term
| What are the operations for mapping types? |
|
Definition
for arrays: indexing
for functions abstractions: calling the function |
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Term
| What are the two types of mappings and how are they implemented in programming languages? |
|
Definition
Finite mappings using arrays
non finite mappings using function abstractions |
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Term
| How would we define (formally and in Pascal) a mapping type that maps integers to strings? What is the cardinality of this new type? |
|
Definition
Integer --> String
#Integer --> #String |
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Term
| Are functions in Pascal the same thing as mathematical functions? Why or why not? |
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Definition
| no, because since the state of global variables can be updated in pascal, a function given the same parameter value may not return the same answer |
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Term
| How would the mapping (Integer X Real X String) --> Truth-Value be implemented in Pascal? |
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Definition
| function add (x:integer; y:string; z:real):boolean; |
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