setConstructor
| Syntax | A setConstructor is:
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| Description | Each value of a set type consists of a set of elements. In classical mathematics, the set consisting of 0 and 1 is written as {0,1}. This is written in Turing using a set constructor consisting of the name of the set type (setTypeId) followed by a parenthesized list of elements.
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| Example | The smallSet type is declared so that it can contain any and all of the values 0, 1 and 2. Variable s is initialized to be the set containing 1 and 2. The set {0,1} is written in this Turing example as smallInt (0,1).
type smallSet : set of 0 .. 2
var s : smallSet := smallSet ( 0, 1 )
…
if 2 in s then …
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| Details | The form of membersOfSet is one of:
(a) expn { , expn} % List of members of set
(b) all % All member of index type of set
(c) % Nothing, meaning the empty set
The empty set is written, for example, as smallInt (). The full set is written as smallInt (all), so smallInt (all) = smallInt (0,1,2). See also the set type.The syntax of setConstructor as given above has been simplified by ignoring the fact that set types can be exported from modules. When a set type is exported and used outside of a module, you must write the module name, a dot and then the type name. For example, the set constructor above would be written as m.smallSet(1,2), where m is the module name.
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