syntax
Extensions
Extensions
Returns a $Nullable containing the result of
applying pf to a Nullable's contained
value, '''if''' a option is
nonempty '''and''' pf is defined for that value.
Returns $null otherwise.
Returns a $Nullable containing the result of
applying pf to a Nullable's contained
value, '''if''' a option is
nonempty '''and''' pf is defined for that value.
Returns $null otherwise.
- Value Params
- pf
the partial function.
- Returns
the result of applying
pfto a Nullable's value (if possible), or $null.- Example
// Returns Nullable(HTTP) because the partial function covers the case. Nullable("http") collect {case "http" => "HTTP"} // Returns null because the partial function doesn't cover the case. Nullable("ftp") collect {case "http" => "HTTP"} // Returns null because the option is empty. There is no value to pass to the partial function. null collect {case value => value}
Tests whether the option contains a given value as an element.
Tests whether the option contains a given value as an element.
- Value Params
- elem
the element to test.
- Returns
trueif the option has an element that is equal (as determined by==) toelem,falseotherwise.- Example
// Returns true because Nullable instance contains string "Nullablething" which equals "Nullablething". Nullable("Nullablething") contains "Nullablething" // Returns false because "Nullablething" != "anything". Nullable("Nullablething") contains "anything" // Returns false when method called on null. null contains "anything"
Returns true if a value is not null '''and''' the predicate $p returns true when applied to the value. Otherwise, returns false.
Returns true if a value is not null '''and''' the predicate $p returns true when applied to the value. Otherwise, returns false.
- Value Params
- p
the predicate to test
Returns a Nullable if it is nonempty '''and''' applying the predicate $p to a Nullable's value returns false. Otherwise, return $null.
Returns a Nullable if it is nonempty '''and''' applying the predicate $p to a Nullable's value returns false. Otherwise, return $null.
- Value Params
- p
the predicate used for testing.
Returns the result of applying $f to a Nullable's
value if the Nullable is nonempty. Otherwise, evaluates
expression ifEmpty.
Returns the result of applying $f to a Nullable's
value if the Nullable is nonempty. Otherwise, evaluates
expression ifEmpty.
a is equivalent to:
nullable map f getOrElse ifEmpty
- Value Params
- f
the function to apply if nonempty.
- ifEmpty
the expression to evaluate if empty.
Returns true if a value is null '''or''' the predicate $p returns true when applied to the value.
Returns true if a value is null '''or''' the predicate $p returns true when applied to the value.
- Value Params
- p
the predicate to test
Apply the given procedure $f to the option's value, if it is nonempty. Otherwise, do nothing.
Apply the given procedure $f to the option's value, if it is nonempty. Otherwise, do nothing.
- Value Params
- f
the procedure to apply.
- See also
map
flatMap
Returns the wrapped value,
unless it's null, in which case it returns the result of evaluating default.
Returns the wrapped value,
unless it's null, in which case it returns the result of evaluating default.
- Value Params
- default
the default (fallback) expression.
Docs and some of the code below has been adaped from scala.Option whose license is:
Docs and some of the code below has been adaped from scala.Option whose license is:
Scala (https://www.scala-lang.org)
Copyright EPFL and Lightbend, Inc.
Licensed under Apache License 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
Returns a singleton iterator returning the Nullable's value if it is nonempty, or an empty iterator if the option is empty.
Returns a singleton iterator returning the Nullable's value if it is nonempty, or an empty iterator if the option is empty.
Returns false if the option is $null, true otherwise.
Returns false if the option is $null, true otherwise.
Returns a Nullable if it is nonempty,
otherwise return the result of evaluating alternative.
Returns a Nullable if it is nonempty,
otherwise return the result of evaluating alternative.
- Value Params
- alternative
the alternative expression.
Returns a scala.util.Right containing the given
argument right if a is empty, or
a scala.util.Left containing a Nullable's value
if a Nullable is nonempty.
Returns a scala.util.Right containing the given
argument right if a is empty, or
a scala.util.Left containing a Nullable's value
if a Nullable is nonempty.
- Value Params
- right
the expression to evaluate and return if a is empty
- See also
toRight
Returns a singleton list containing the Nullable's value if it is nonempty, or the empty list if the Nullable is empty.
Returns a singleton list containing the Nullable's value if it is nonempty, or the empty list if the Nullable is empty.
Returns a scala.util.Left containing the given
argument left if a Nullable is empty, or
a scala.util.Right containing a Nullable's value if
a is nonempty.
Returns a scala.util.Left containing the given
argument left if a Nullable is empty, or
a scala.util.Right containing a Nullable's value if
a is nonempty.
- Value Params
- left
the expression to evaluate and return if a is empty
- See also
toLeft
Converts a Nullable of a pair into a Nullable of the first element and a Nullable of the second element.
Converts a Nullable of a pair into a Nullable of the first element and a Nullable of the second element.
- Type Params
- A1
the type of the first half of the element pair
- A2
the type of the second half of the element pair
- Value Params
- asPair
an implicit conversion which asserts that the element type of a Option is a pair.
- Returns
a pair of Options, containing, respectively, the first and second half of the element pair of a Option.
Converts a Nullable of a triple into three Options, one containing the element from each position of the triple.
Converts a Nullable of a triple into three Options, one containing the element from each position of the triple.
- Type Params
- A1
the type of the first of three elements in the triple
- A2
the type of the second of three elements in the triple
- A3
the type of the third of three elements in the triple
- Value Params
- asTriple
an implicit conversion which asserts that the element type of a Option is a triple.
- Returns
a triple of Options, containing, respectively, the first, second, and third elements from the element triple of a Option.
Returns a $Nullable formed from a option and another option by combining the corresponding elements in a pair. If either of the two options is empty, $null is returned.
Returns a $Nullable formed from a option and another option by combining the corresponding elements in a pair. If either of the two options is empty, $null is returned.
- Value Params
- that
the options which is going to be zipped
- Example
// Returns Nullable(("foo", "bar")) because both options are nonempty. Nullable("foo") zip Nullable("bar") // Returns null because `that` option is empty. Nullable("foo") zip null // Returns null because `a` option is empty. null zip Nullable("bar")