# OCL operation reference

## Ocl operations for type *Classifier*

### allInstances () : Set{T}

Returns a Set containing all of the existing instances of the current classifier (along with instances of all its inherited classifiers).

Expression | Result
--- | ---
let a : String = 'a', b : String = 'b', c : Integer = 2 in String.allInstances() | Set{'a','b'}

## Ocl operations for type *OclAny*

### oclAsType ( typespec : Classifier ) : T

Returns *self* statically typed as typespec if it is an instance of this type. *Note* that this does not alter the runtime value of *self*, it only enables access to subtype operations. This operation allows users to cast self to another type.

Expression | Result
--- | ---
aPerson.oclAsType(Employee) | an object of Employee type

### oclIsInvalid () : Boolean

Returns true if self is equal to *invalid*.

Expression | Result
--- | ---
let anObject : String = null in anObject.oclIsUndefined() | false
let anObject : String = invalid in anObject.oclIsUndefined() | true
let anObject : String = 'null' in anObject.oclIsUndefined() | false

### oclIsKindOf( Classifier typespec ) : Boolean

Returns **true** if the type of self corresponds to the type or supertype of typespec, false otherwise. This operation allows users to check the class hierarchy of self much like would an instanceof Java.

Expression | Result
--- | ---
anEmployee.oclIsKindOf(Employee) | true
anEmployee.oclIsKindOf(Person) | true
aCat.oclIsKindOf(Person) | false

### oclIsTypeOf( typespec : Classifier ) : Boolean

Returns true if the type of self is the same as typespec, or **false** otherwise. This operation allows users to check the exact class type of self.

Expression | Result
--- | ---
anEmployee.oclIsTypeOf(Employee) | true
anEmployee.oclIsTypeOf(Person) | false
aCat.oclIsTypeOf(Person) | false

### oclIsUndefined () : Boolean

Returns **true** if *self* is equal to *invalid* or *null*.

Expression | Result
--- | ---
let anObject : String = null in anObject.oclIsUndefined() | true
let anObject : String = invalid in anObject.oclIsUndefined() | true
let anObject : String = 'null' in anObject.oclIsUndefined() | false

### <> ( object : OclAny ) : Boolean

Returns **true** if *self* is a different object from *object*.

Expression | Result
--- | ---
let a : String = 'a', b : String = 'a' in a <> b | false
let a : Integer = 2, b : Real = 2.0 in a <> b | false
let a : Integer = -2, b : Integer = 2 in a <> b | true

### = ( object : OclAny) : Boolean

Returns **true** if *self* is equal to *object*.

Expression | Result
--- | ---
let a : String = 'a', b : String = 'a' in a = b | true
let a : Integer = 2, b : Real = 2.0 in a = b | true
let a : Integer = -2, b : Integer = 2 in a = b | false

### < ( object : T ) : Boolean

Returns **true** if *self* is comparable to *object* and less than *object*.

Expression | Result
--- | ---
let a : Integer = 1, b : Integer = 2 in a < b | true
let a : Real = 1.5, b : Integer = 2 in a < b | true
let a : String = 'Anteater', b : String = 'Aardvark' in a < b | false

### > ( object : T ) : Boolean

Returns **true** if *self* is comparable to *object* and greater than *object*.

Expression | Result
--- | ---
let a : Integer = 1, b : Integer = 2 in a > b | false
let a : Real = 1.5, b : Integer = 2 in a > b | false
let a : String = 'Anteater', b : String = 'Aardvark' in a > b | true

### <= ( object : T ) : Boolean

Returns **true** if *self* is comparable to *object* and less than or equal to *object*.

Expression | Result
--- | ---
let a : Integer = 1, b : Integer = 2 in a <= b | true
let a : Real = 1.5, b : Integer = 2 in a <= b | true
let a : String = 'Anteater', b : String = 'Aardvark' in a <= b | false

### >= ( object : T ) : Boolean

Returns **true** if *self* is comparable to *object* and greater than or equal to *object*.

Expression | Result
--- | ---
let a : Integer = 1, b : Integer = 2 in a >= b | false
let a : Real = 1.5, b : Integer = 2 in a >= b | false
let a : String = 'Anteater', b : String = 'Aardvark' in a >= b | true

## Ocl operations for type *String*

- - A note on Strings** : OCL Strings begin at index *1*, not *0* as in most languages. Thus *'test'.at(0)* fails in
- invalid* whereas *'test'.at(1)* yields *'t'*. Likewise, *'test'.substring(2, 2)* returns *'e'*.

### concat ( s : String ) : String

Returns a string containing *self* followed by *s*.

Expression | Result
--- | ---
'concat'.concat(' ').concat('operation') | 'concat operation'

### size () : Integer

Returns the number of characters composing *self*.

Expression | Result
--- | ---
'size operation'.size() | 14

### substring ( lower : Integer, upper : Integer ) : String

Returns a string containing all characters from *self* starting from index *lower* up to index *upper* included. Both *lower* and *upper* parameters should be contained between *1* and *self.size()* included. *lower* cannot be greater than *upper*.

Expression | Result
--- | ---
'substring operation'.substring(11, 19) | 'operation'
'substring operation'.substring(1, 1) | 's'
'substring operation'.substring(0, 1) | invalid

### toInteger () : Integer

Returns an Integer of value equal to *self*, or |invalid| if *self* does not represent an integer.

Expression | Result
--- | ---
'3.0'.toInteger() | invalid
'4'.toInteger() | 4
'toInteger'.toInteger() | invalid

### toLower () : String

Returns *self* with all characters converted to lowercase.

Expression | Result
--- | ---
'LoWeR OpErAtIoN'.toLower() | 'lower operation'

### toReal () : Real

Returns a Real of value equal to *self*, or |invalid| if *self* does not represent a real.

Expression | Result
--- | ---
'3.0'.toReal() | 3.0
'4'.toReal() | 4.0
'toReal'.toReal() | invalid

### toUpper () : String

Returns *self* with all characters converted to uppercase.

Expression | Result
--- | ---
'UpPeR OpErAtIoN'.toUpper() | 'UPPER OPERATION'

## Ocl operations for type *Number*

In addition to the basic math functions (+, -, /, \*) are a number of advanced functions. Take note that *Number* denotes both *Integer* and *Real*, and they're substitutive unless otherwise specified.

### Number::abs () : Number

Returns the absolute value of *self*, *self* if it is already a positive number.

Expression | Result
--- | ---
(-2.3).abs() | 2.3
-5.abs() | 5

### Number::floor () : Integer

Returns the integer part of *self* if it is a Real, *self* if it is an Integer.

Expression | Result
--- | ---
(2.3).floor() | 2
(2.8).floor() | 2
2.floor() | 2

### Number::max ( r : Number ) : Number

Returns the greatest number between *self* and *r*.

Expression | Result
--- | ---
6.max(3) | 6
6.max(5.2) | 6.0
(2.3).max(3) | 3.0
(2.3).max(5.2) | 5.2

### Number::min ( r : Number ) : Number

Returns the lowest number between *self* and *r*.

Expression | Result
--- | ---
6.min(3) | 3
6.min(5.2) | 5.2
(2.3).min(3) | 2.3
(2.3).min(5.2) | 2.3

### Number::round () : Integer

Returns the nearest integer to *self* if it is a Real, *self* if it is an Integer.

Expression | Result
--- | ---
(2.3).round() | 2
(2.5).round() | 3
(2.8).round() | 3
2.round() | 2

### Integer::div ( i : Integer ) : Integer

Returns the integer quotient of the division of *self* by *i*.

Expression | Result
--- | ---
3.div(2) | 1
11.div(3) | 3

### Integer::mod ( i : Integer ) : Integer

Returns the integer remainder of the division of *self* by *i*.

Expression | Result
--- | ---
3.mod(2) | 1
11.mod(3) | 2

## Ocl operations for type *Collection*

Please note that OCL collections can contain the *null* value (null) but not the *invalid* value (|invalid|). Trying to add |invalid| within a new or existing collection will yield |invalid| as a result. OCL proposes four distinct kinds of collections offering all possibilities of ordering/unicity.

Collection type | Ordered | Unique
--- | --- | ---
Sequence | true | false
OrderedSet | true | true
Bag | false | false
Set | false | true

### any ( expr : OclExpression ) : T

Returns any element contained in *self* that validates the condition *expr*, null otherwise. Evaluation is shortcut as soon as an element validating *expr* is found. Note that the result of this on unordered collections will be random if more than one element validates *expr*.

Expression | Result
--- | ---
Sequence{1.2, 2.3, 5.2, 0.9}->any(self < 1) | 0.9
Sequence{1.2, 2.3, 5.2, 0.9}->any(self < 2) | 1.2

### asBag () : Bag(T)

Returns a Bag containing all elements of *self*.

Expression | Result
--- | ---
Sequence{'3', 1, 2.0, '3'}->asBag() | Bag{2.0, '3', 1, '3'}
Bag{1, 2.0, '3'}->asBag() | Bag{2.0, 1, '3'}
OrderedSet{1, 2.0, '3'}->asBag() | Bag{2.0, 1, '3'}
OrderedSet{1, 1, 2.0, '3'}->asBag() | Bag{'3', 1, 2.0}
Set{1, 2.0, '3'}->asBag() | Bag{2.0, 1, '3'}
Set{1, 1, 2.0, '3'}->asBag() | Bag{2.0, '3', 1}

### asOrderedSet () : OrderedSet(T)

Returns an OrderedSet containing all elements of *self*. Element ordering is preserved when possible.

Expression | Result
--- | ---
Sequence{1, 2.0, '3'}->asOrderedSet() | OrderedSet{1, '3', 2.0}
Sequence{1, 1, 2.0, '3'}->asOrderedSet() | OrderedSet{'3', 1, 2.0}
Bag{1, 2.0, '3'}->asOrderedSet() | OrderedSet{2.0, 1, '3'}
Bag{1, 1, 2.0, '3'}->asOrderedSet() | OrderedSet{1, '3', 2.0}
OrderedSet{1, 2.0, '3'}->asOrderedSet() | OrderedSet{1, 2.0, '3'}
Set{1, 2.0, '3'}->asOrderedSet() | OrderedSet{'3', 1, 2.0}

### asSequence () : Boolean

Returns a Sequence containing all elements of *self*. Element ordering is preserved when possible.

Expression | Result
--- | ---
Sequence{1, 2.0, '3'}->asSequence() | Sequence{1, 2.0, '3'}
Bag{1, 2.0, '3'}->asSequence() | Sequence{2.0, 1, '3'}
OrderedSet{1, 2.0, '3'}->asSequence() | Sequence{1, 2.0, '3'}
Set{1, 2.0, '3'}->asSequence() | Sequence{'3', 1, 2.0}

### asSet () : Set(T)

Returns a Set containing all elements of *self*.

Expression | Result
--- | ---
Sequence{1, 2.0, '3'}->asSet() | Set{1, '3', 2.0}
Sequence{1, 1, 2.0, '3'}->asSet() | Set{'3', 1, 2.0}
Bag{1, 2.0, '3'}->asSet() | Set{2.0, 1, '3'}
Bag{1, 1, 2.0, '3'}->asSet() | Set{1, '3', 2.0}
OrderedSet{1, 2.0, '3'}->asSet() | Set{1, '3', 2.0}
OrderedSet{1, 1, 2.0, '3'}->asSet() | Set{'3', 1, 2.0}
Set{1, 2.0, '3'}->asSet() | Set{2.0, 1, '3'}
Set{1, 1, 2.0, '3'}->asSet() | Set{'3', 1, 2.0}

### collect ( expr : OclExpression ) : Collection(T2)

Returns a collection containing the result of applying *expr* on all elements contained in *self*.

Expression | Result
--- | ---
Sequence{'first', 'second'}->collect(toUpper()) | Sequence{'FIRST', 'SECOND'}

### collectNested ( expr : OclExpression ) : Collection(T2)

Returns a collection containing all the elements contained in *self* on which we applied the OclExpression *expr*. The results won't be flattened. The type of the resulting collection depends on the type of *self*.

For the purpose of these examples we'll assume here that we have a Class *Person* with a reference *children*. Our model contains two persons such as *person1.children = {James, Jane}* and *person2.children = {John}*.

Expression | Result
--- | ---
self.persons->collectNested(children.firstname) | Sequence{Sequence{James, Jane}, Sequence{John}}

### count ( object : T ) : Integer

Returns how many times *object* is in the collection *self*.

Expression | Result
--- | ---
Sequence{2.3, 5.2}->count(5.2) | 1
Set{3, 'test', 4.0, 4, 4.0, 'test'}->count(null) | 0
Set{3, null, 4.0, null, 'test'}->count(null) | 1
Bag{3, null, 4.0, null, 'test'}->count(null) | 2

### excludes ( object : T ) : Boolean

Returns **true** if *object* is not contained in *self*, **false** otherwise.

Expression | Result
--- | ---
Sequence{2.3}->excludes(2.1) | true
Sequence{2.0}->excludes(2) | false

### excludesAll ( c2 : Collection(T) ) : Boolean

Returns **true** if no element of *c2* is contained in *self*, **false** otherwise.

Expression | Result
--- | ---
Sequence{2.3, 5.2, 'a', 3, null}->excludesAll(Set{4, null}) | false
Sequence{2.3, 5.2, 'a', 3}->excludesAll(Set{4, null}) | true

### excluding ( object : T ) : Collection(T)

Returns a collection containing all elements of *self* minus all occurences of *object*. **Note** : at the time of writing, the OCL standard library sports a bug which changes *OrderedSets* in *Sets* when excluding elements.

Expression | Result
--- | ---
Sequence{'b', 'a', 'b', 'c'}->excluding('b') | Sequence{'a', 'c'}
Bag{'b', 'a', 'b', 'c'}->excluding('b') | Bag{'c', 'a'}
OrderedSet{'b', 'a', 'b', 'c'}->excluding('b') | Set{'c', 'a'}
Set{'b', 'a', 'b', 'c'}->excluding('b') | Set{'c', 'a'}

### exists ( expr : OclExpression ) : Boolean

Returns **true** if at least one element in *self* validates the condition *expr*, **false** otherwise. The evaluation stops as soon as one element validating *expr* is found.

Expression | Result
--- | ---
Sequence{2.3, 5.2}->exists(self > 3) | true

### flatten () : Collection(T2)

Returns a collection containing all elements of *self* recursively flattened. **Note** : at the time of writing, the OCL standard library sports a bug which changes *OrderedSets* in *Sets* when flattening.

Expression | Result
--- | ---
Sequence{Set{1, 2, 3}, Sequence{2.0, 3.0}, Bag{'test'}}->flatten() | Sequence{1, 2, 3, 2.0, 3.0, 'test'}
Bag{Set{Bag{'test', 2, 3.0}}, Sequence{OrderedSet{2.0, 3, 1}}}->flatten() | Bag{1, 2, 3, 2.0, 3.0, 'test'}
OrderedSet{Set{Bag{'test', 2, 3.0}}, Sequence{Set{2.0, 3, 1}}}->flatten() | Set{3.0, 2, 1, 3, 'test', 2.0}
Set{Set{Bag{'test', 2, 3.0}}, Sequence{OrderedSet{2.0, 3, 1}}}->flatten() | Set{3.0, 2, 1, 3, 'test', 2.0}

### forAll ( expr : OclExpression ) : Boolean

Returns **true** if the all the elements contained in *self* validate the condition *expr*, **false** otherwise.

Expression | Result
--- | ---
Sequence{2.3, 5.2}->forAll(self > 3) | false
Sequence{2.3, 5.2}->forAll(self > 1.2) | true

### includes ( object : T ) : Boolean

Returns **true** if *object* is contained in *self*, **false** otherwise.

Expression | Result
--- | ---
Sequence{2.3}->includes(2.1) | false
Sequence{2.0}->includes(2) | true

### includesAll ( c2 : Collection(T) ) : Boolean

Returns **true** if all element of *c2* are contained in *self*, **false** otherwise.

Expression | Result
--- | ---
Sequence{2.3, 5.2, 'a', 3, null}->includesAll(Set{3, null}) | true
Sequence{2.3, 5.2, 'a', 3}->includesAll(Set{3, null}) | false

### including ( object : T ) : Collection(T)

Returns a collection containing all elements of *self* followed by *object*. **Note** : at the time of writing, the OCL standard library sports a bug which changes *OrderedSets* in *Sets* when including elements.

Expression | Result
--- | ---
Sequence{'a', 'b'}->including('c') | Sequence{'a', 'b', 'c'}
Bag{'a', 'b'}->including('c') | Bag{'a', 'c', 'b'}
OrderedSet{'a', 'b'}->including('c') | Set{'a', 'c', 'b'}
Set{'a', 'b'}->including('c') | Set{'a', 'c', 'b'}

### isEmpty () : Boolean

Returns **true** if *self* is empty, **false** otherwise.

Expression | Result
--- | ---
Sequence{2, 'a'}->isEmpty() | false
Sequence{null}->isEmpty() | false
Sequence{}->isEmpty() | true

### isUnique ( expr : OclExpression ) : Boolean

Returns **true** if all elements contained in *self* evaluate to a distinct value for *expr*.

Expression | Result
--- | ---
Sequence{2.3, 5.2}->isUnique(self > 3) | true
Sequence{2.3, 5.2}->isUnique(self > 1) | false

### notEmpty () : Boolean

Returns **true** if *self* contains at least one element, **false** otherwise.

Expression | Result
--- | ---
Sequence{2, 'a'}->notEmpty() | true
Sequence{null}->notEmpty() | true
Sequence{}->notEmpty() | false

### one ( expr : OclExpression ) : Boolean

Returns **true** if there is only one element contained in *self* that validates the condition *expr*, **false** otherwise.

Expression | Result
--- | ---
Sequence{1.2, 2.3, 5.2, 0.9}->one(self < 1) | true
Sequence{1.2, 2.3, 5.2, 0.9}->one(self < 2) | false

### product ( c2 : Collection(T2) ) : Set(Tuple(first : T, second : T2))

Returns a Set of Tuples which represents the cartesian product of *self* with *c2*.

Expression | Result
--- | ---
Sequence{3, 4}->product(Bag{3.0, 4.0}) | Set{Tuple{3, 3.0}, Tuple{3, 4.0}, Tuple{4, 3.0}, Tuple{4, 4.0}}
Set{3, 4}->product(OrderedSet{3.0, 4.0}) | Set{Tuple{3, 3.0}, Tuple{3, 4.0}, Tuple{4, 3.0}, Tuple{4, 4.0}}

### reject ( expr : OclExpression ) : Collection(T)

Returns a collection with all elements of *self* except for those who validate the OclExpression *expr*.

Expression | Result
--- | ---
i > 1 ) | Sequence{1}
i > 1 ) | Bag{1}
i > 1 ) | OrderedSet{1}
i > 1 ) | Set{1}

### select ( expr : OclExpression ) : Collection(T)

Returns a collection with all elements of *self* that validate the OclExpression *expr*.

Expression | Result
--- | ---
i > 1) | Sequence{2, 3}
i > 1 ) | Bag{3, 2}
i > 1 ) | OrderedSet{2, 3}
i > 1 ) | Set{3, 2}

### size () : Integer

Returns the number of elements contained in *self*.

Expression | Result
--- | ---
Sequence{2.3, 5}->size() | 2
Sequence{}->size() | 0

### sortedBy ( expr : OclExpression ) : Sequence(T)

Returns a sorted collection containing all elements from *self* sorted in accordance with the OclExpression *expr*. This can be used on all kind of collections yet will always yield a Sequence-typed result except for OrderedSet which returns an OrderedSet.

For the purpose of these examples we'll assume here that we have a Class *Employee* with an attribute *age*. Our model contains two employees such as *employee1.age = 24* and *employee2.age = 27*.

Expression | Result
--- | ---
self.employees->sortedBy(age) | Sequence{employee1, employee2}

### sum () : Real

Returns the sum of all elements contained in *self* if they support the '+' operation.

Expression | Result
--- | ---
Sequence{2.3, 5.2} in c->sum() | 7.5
Sequence{2, 4} in c->sum() | 6
Sequence{2, '4'} in c->sum() | invalid

## Ocl operations for type *Sequence*

### = ( seq : Sequence(T) ) : Boolean

Returns **true** if *self* contains the very same objects as *seq* in the very same order as they are in *seq*.

Expression | Result
--- | ---
Sequence{4, 5, 'test'} = Sequence{4, 5, 'test'} | true
Sequence{4, 5, 'test'} = Sequence{4, 'test', 5} | false
Sequence{4, 5, 'test', 5} = Sequence{4, 5, 'test'} | false

### <> ( seq : Sequence(T) ) : Boolean

Returns **true** if *self* does not contain the same objects as *seq*, or if these objects are not in the same order as they are in *seq*.

Expression | Result
--- | ---
Sequence{4, 5, 'test'} = Sequence{4, 5, 'test'} | false
Sequence{4, 5, 'test'} = Sequence{4, 'test', 5} | true
Sequence{4, 5, 'test', 5} = Sequence{4, 5, 'test'} | true

### append ( object : T ) : Sequence(T)

Returns a Sequence containing all elements of *self* followed by *object*.

Expression | Result
--- | ---
Sequence{'a', 'b'}->append('c') | Sequence{'a', 'b', 'c'}

### at ( index : Integer ) : T

Returns the element of *self* at the *index* position.

Expression | Result
--- | ---
Sequence{'a', 'b'}->at(1) | a

### first () : T

Returns the first element of *self*.

Expression | Result
--- | ---
Sequence{1, 2.0, '3'}->first() | 1

### indexOf ( object : T ) : Integer

Returns the position of *object* in sequence *self*.

Expression | Result
--- | ---
Sequence{'a', 'b'}->indexOf('a') | 1

### insertAt ( index : Integer, object : T) : Sequence(T)

Returns a Sequence containing *self* with *object* inserted at the *index* position.

Expression | Result
--- | ---
Sequence{'a', 'b'}->insertAt(0, 'c') | invalid
Sequence{'a', 'b'}->insertAt(1, 'c') | Sequence{'c', 'a', 'b'}
Sequence{'a', 'b'}->insertAt(3, 'c') | Sequence{'a', 'b', 'c'}
Sequence{'a', 'b'}->insertAt(4, 'c') | invalid

### last () : T

Returns the last element of *self*.

Expression | Result
--- | ---
Sequence{1, 2.0, '3'}->last() | '3'

### prepend ( object : T ) : Sequence(T)

Returns a Sequence containing *object* followed by all elements of *self* .

Expression | Result
--- | ---
Sequence{'a', 'b'}->prepend('c') | Sequence{'c', 'a', 'b'}

### subSequence ( startIndex : Integer, endIndex : Integer ) : Sequence(T)

Returns a Sequence containing all elements of *self* between the positions 'startIndex' and 'endIndex'.

Expression | Result
--- | ---
Sequence{'a', 'b', 'c', 'd'}->subSequence(2, 3) | Sequence{'b', 'c'}
Sequence{'a', 'b', 'c', 'd'}->subSequence(4, 4) | Sequence{'d'}

### union ( seq : Sequence(T) ) : Sequence(T)

Returns a Sequence containing all elements of *self* followed by all elements of *seq*.

Expression | Result
--- | ---
Sequence{'a', 'b', 'a'}->union(Sequence{'b', 'c'}) | Sequence{'a', 'b', 'a', 'b', 'c'}

## Ocl operations for type *Bag*

### = ( bag : Bag(T) ) : Boolean

Returns **true** if *self* contains the same objects as *bag* in the same quantities.

Expression | Result
--- | ---
Bag{4, 5, 'test', 4} = Bag{4, 'test', 5, 4} | true
Bag{4, 5, 'test'} = Bag{4, 'test', 5} | true
Bag{4, 5, 'test', 5} = Bag{4, 5, 'test'} | false

### <> ( bag : Bag(T) ) : Boolean

Returns **true** if *self* does not contain the same objects as *bag* in the same quantities.

Expression | Result
--- | ---
Bag{4, 5, 'test'} = Bag{4, 5, 'test'} | false
Bag{4, 5, 'test'} = Bag{4, 'test', 5} | false
Bag{4, 5, 'test', 5} = Bag{4, 5, 'test'} | true

### intersection ( bag : Bag(T) ) : Bag(T)

Returns a Bag containing all elements of *self* that are also contained by *bag*.

Expression | Result
--- | ---
Bag{'a', 'b', 'a'}->intersection(Bag{'a', 'b'}) | Bag{'a', 'b'}
Bag{'a', 'b', 'a', 'b'}->intersection(Bag{'a', 'b', 'b'}) | Bag{'b', 'a', 'b'}

### intersection ( set : Set(T) ) : Set(T)

Returns a Set containing all elements of *self* that are also contained by *set*.

Expression | Result
--- | ---
Bag{'a', 'b', 'a'}->intersection(Set{'a', 'b', 'c'}) | Set{'a', 'b'}

### union ( bag : Bag(T) ) : Bag(T)

Returns a Bag containing all elements of *self* and all elements of *bag*.

Expression | Result
--- | ---
Bag{'a', 'b', 'a'}->union(Bag{'b', 'c'}) | Bag{'b', 'a', 'b', 'a', 'c'}

### union ( set : Set(T) ) : Bag(T)

Returns a Bag containing all elements of *self* and all elements of *set*.

Expression | Result
--- | ---
Bag{'a', 'b', 'a'}->union(Set{'b', 'c'}) | Bag{'b', 'c', 'a', 'b', 'a'}

## Ocl operations for type *OrderedSet*

### = ( set : Set(T) ) : Boolean

Returns **true** if *self* contains the same objects as *set*.

Expression | Result
--- | ---
OrderedSet{3, 5, 4} = Set{3, 5, 4} | true
OrderedSet{3, 5, 4} = Set{4, 3, 5, 4, 4} | true
OrderedSet{3, 5, 4} = Set{2, 5 ,4, 4} | false

### = ( orderedset : OrderedSet(T) ) : Boolean

Returns **true** if *self* contains the same objects as *orderedset* regardless of element ordering.

Expression | Result
--- | ---
OrderedSet{3, 5, 4} = OrderedSet{3, 5, 4} | true
OrderedSet{4, 5, 'test', 5} = OrderedSet{4, 5, 'test'} | true
OrderedSet{4, 5, 'test'} = OrderedSet{4, 'test', 5} | true
OrderedSet{4, 5, 'test'} = OrderedSet{4, 'test'} | false

### <> ( set : Set(T) ) : Boolean

Returns **true** if *self* does not contain the same objects as *set*.

Expression | Result
--- | ---
OrderedSet{4, 5, 'test', 4} <> Set{4, 5, 'test'} | false
OrderedSet{4, 5, 'test', 4} <> Set{4, 'test', 5, 4} | false
OrderedSet{4, 5, 'test', 4} <> Set{4, 5, 'test', 2} | true

### <> ( orderedset : OrderedSet(T) ) : Boolean

Returns **true** if *self* does not contain the same objects as *orderedset*.

Expression | Result
--- | ---
OrderedSet{4, 5, 'test', 4} <> OrderedSet{4, 5, 'test') | false
OrderedSet{4, 5, 'test', 4} <> OrderedSet{4, 'test', 5, 4} | false
OrderedSet{4, 5, 'test', 4} <> OrderedSet{4, 5, 'test', 2} | true

### `-` ( set : Set(T) ) : Set(T)

Returns a Set containing all elements of *self* minus all elements of *set*.

Expression | Result
--- | ---
OrderedSet{'a', 'b', 'c'} - Set{'c', 'a'} | Set{'b'}

### append ( object : T ) : OrderedSet(T)

Returns an OrderedSet containing all elements of *self* followed by *object*.

Expression | Result
--- | ---
OrderedSet{'a', 'b'}->append('c') | OrderedSet{'a', 'b', 'c'}

### at ( index : Integer ) : T

Returns the element of *self* located at position *index* in the collection.

Expression | Result
--- | ---
OrderedSet{'a', 'b'}->at(1) | 'a'

### first () : T

Returns the first element of *self*.

Expression | Result
--- | ---
OrderedSet{1, 2.0, '3'}->first() | 1

### indexOf ( object : T ) : Integer

Returns the position of *object* in *self*.

Expression | Result
--- | ---
OrderedSet{'a', 'b'}->indexOf('a') | 1

### insertAt ( index : Integer, object : T ) : OrderedSet(T)

Returns an OrderedSet containing *self* with *object* inserted at the *index* position.

Expression | Result
--- | ---
OrderedSet{'a', 'b'}->insertAt(1, 'c') | OrderedSet{'c', 'a', 'b'}
OrderedSet{'a', 'b'}->insertAt(3, 'c') | OrderedSet{'a', 'b', 'c'}

### intersection ( bag : Bag(T) ) : Set(T)

Returns a Set containing all elements of *self* that are also contained by *bag*.

Expression | Result
--- | ---
OrderedSet{'a', 'b', 'a'}->intersection(Bag{'a', 'b'}) | Set{'a', 'b'}

### intersection ( set : Set(T) ) : Set(T)

Returns a Set containing all elements of *self* that are also contained by *set*.

Expression | Result
--- | ---
OrderedSet{'a', 'b', 'a'}->intersection(Set{'a', 'b'}) | Set{'a', 'b'}

### last () : T

Returns the last element of *self*.

Expression | Result
--- | ---
OrderedSet{1, 2.0, '3'}->last() | '3'

### prepend ( object : T ) : OrderedSet(T)

Returns an OrderedSet containing *object* followed by all elements of *self*.

Expression | Result
--- | ---
OrderedSet{'a', 'b'}->prepend('c') | OrderedSet{'c', 'a', 'b'}

### subOrderedSet ( startIndex : Integer, endIndex : Integer ) : OrderedSet(T)

Returns an OrderedSet containing all elements of *self* between the positions *startIndex* and *endIndex*.

Expression | Result
--- | ---
OrderedSet{'a', 'b', 'c', 'd'}->subOrderedSet(2, 3) | OrderedSet{'b', 'c'}
OrderedSet{'a', 'b', 'c', 'd'}->subOrderedSet(4, 4) | OrderedSet{'d'}

### symmetricDifference ( set : Set(T) ) : Set(T)

Returns a Set containing all of the elements of *self* and *set* that are not present in both.

Expression | Result
--- | ---
OrderedSet{'b', 'a', 'b', 'c'}->symmetricDifference(Set{'a', 'c', 'd'}) | Set{'d', 'b'}

### union ( bag : Bag(T) ) : Bag(T)

Returns a Bag containing all elements of *self* followed by all elements of *bag*.

Expression | Result
--- | ---
OrderedSet{'a', 'b', 'a'}->union(Bag{'b', 'c'}) | Bag{'a', 'c', 'b', 'b'}

### union ( set : Set(T) ) : Set(T)

Returns a Set containing all elements of *self* followed by all elements of *set*.

Expression | Result
--- | ---
OrderedSet{'a', 'b', 'a'}->union(Set{'b', 'c'}) | Set{'a', 'c', 'b'}

## Ocl operations for type *Set*

### = ( set : Set(T) ) : Boolean

Returns **true** if *self* contains the same objects as *set*.

Expression | Result
--- | ---
Set{3, 5, 4} = Set{3, 5, 4} | true
Set{3, 5, 4} = Set{3, 4, 4, 5} | true
Set{3, 5, 4} = Set{2, 3, 5, 4} | false

### <> ( set : Set(T) ) : Boolean

Returns **true** if *self* does not contain the same objects as *set*.

Expression | Result
--- | ---
Set{4, 5, 'test', 4} <> Set{4, 5, 'test'} | false
Set{4, 5, 'test', 4} <> Set{5, 4, 'test', 4} | false
Set{4, 5, 'test', 4} <> Set{4, 'test', 5, 2} | true

### `-` ( set : Set(T) ) : Set(T)

Returns a Set containing all elements of *self* minus all elements of *set*.

Expression | Result
--- | ---
Set{'a', 'b', 'c'} - Set{'c', 'a'} | Set{'b'}

### intersection ( bag : Bag(T) ) : Set(T)

Returns a Bag containing all elements of *self* that are also contained in *bag*.

Expression | Result
--- | ---
Set{'a', 'b', 'a'}->intersection(Bag{'a', 'b', 'c'}) | Set{'a', 'b'}

### intersection ( set : Set(T) ) : Set(T)

Returns a Set containing all elements of *self* that are also contained in *set*.

Expression | Result
--- | ---
Set{'a', 'b', 'a'}->intersection(Set{'a', 'b', 'c'}) | Set{'b', 'a'}

### symmetricDifference ( set : Set(T) ) : Set(T)

Returns a Set containing all of the elements of *self* and *set* that are not present in both.

Expression | Result
--- | ---
Set{'b', 'a', 'b', 'c'}->symmetricDifference(Set{'a', 'c', 'd'}) | Set{'b', 'd'}

### union ( bag : Bag(T) ) : Bag(T)

Returns a Bag containing all elements of *self* and all elements of *bag*.

Expression | Result
--- | ---
Set{'a', 'b', 'a'}->union(Bag{'b', 'c'}) | Bag{'a', 'c', 'b', 'b'}

### union ( set : Set(T) ) : Set(T)

Returns a Set containing all elements of *self* and all elements of *set*.

Expression | Result
--- | ---
Set{'a', 'b', 'a'}->union(Set{'b', 'c'}) | Set{'a', 'c', 'b'}

## Ocl operations for type *Boolean*

### And

And | True | False | Invalid
--- | --- | --- | ---
True | true | false | true
False | false | false | false
Invalid | invalid | false | invalid

### Implies

Implies | True | False | Invalid
--- | --- | --- | ---
True | true | false | invalid
False | true | true | true
Invalid | true | invalid | invalid

### Or

Or | True | False | Invalid
--- | --- | --- | ---
True | true | true | true
False | true | false | invalid
Invalid | true | invalid | invalid

### Not

Not | Result
--- | ---
True | false
False | true
Invalid | invalid

### Xor

Xor | True | False | Invalid
--- | --- | --- | ---
True | false | true | invalid
False | true | false | invalid
Invalid | invalid | invalid | invalid