Map2
Attributes
Members list
Value members
Concrete methods
Retrieves the value which is associated with the given key.
Retrieves the value which is associated with the given key. This method invokes the default method of the map if there is no mapping from the given key to a value. Unless overridden, the default method throws a NoSuchElementException.
Value parameters
- key
-
the key
Attributes
- Returns
-
the value associated with the given key, or the result of the map's
defaultmethod, if none exists. - Definition Classes
- Source
- Map.scala
Tests whether a predicate holds for at least one element of this immutable map.
Tests whether a predicate holds for at least one element of this immutable map.
Note: may not terminate for infinite-sized collections.
Value parameters
- p
-
the predicate used to test elements.
Attributes
- Returns
-
trueif the given predicatepis satisfied by at least one element of this immutable map, otherwisefalse - Definition Classes
- Source
- Map.scala
Tests whether a predicate holds for all elements of this immutable map.
Tests whether a predicate holds for all elements of this immutable map.
Note: may not terminate for infinite-sized collections.
Value parameters
- p
-
the predicate used to test elements.
Attributes
- Returns
-
trueif this immutable map is empty or the given predicatepholds for all elements of this immutable map, otherwisefalse. - Definition Classes
- Source
- Map.scala
Applies f to each element for its side effects.
Applies f to each element for its side effects. Note: U parameter needed to help scalac's type inference.
Attributes
- Definition Classes
- Source
- Map.scala
Optionally returns the value associated with a key.
Optionally returns the value associated with a key.
Value parameters
- key
-
the key value
Attributes
- Returns
-
an option value containing the value associated with
keyin this map, orNoneif none exists. - Source
- Map.scala
Returns the value associated with a key, or a default value if the key is not contained in the map.
Returns the value associated with a key, or a default value if the key is not contained in the map.
Type parameters
- V1
-
the result type of the default computation.
Value parameters
- default
-
a computation that yields a default value in case no binding for
keyis found in the map. - key
-
the key.
Attributes
- Returns
-
the value associated with
keyif it exists, otherwise the result of thedefaultcomputation. - Definition Classes
- Source
- Map.scala
Calculates a hash code value for the object.
Calculates a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.
Attributes
- Returns
-
the hash code value for this object.
- Definition Classes
- Source
- Map.scala
Tests whether the immutable map is empty.
Tests whether the immutable map is empty.
Note: The default implementation creates and discards an iterator.
Note: Implementations in subclasses that are not repeatedly iterable must take care not to consume any elements when isEmpty is called.
Attributes
- Returns
-
trueif the immutable map contains no elements,falseotherwise. - Definition Classes
- Source
- Map.scala
An scala.collection.Iterator over the elements of this immutable map.
An scala.collection.Iterator over the elements of this immutable map.
If an IterableOnce object is in fact an scala.collection.Iterator, this method always returns itself, in its current state, but if it is an scala.collection.Iterable, this method always returns a new scala.collection.Iterator.
Attributes
- Source
- Map.scala
The number of elements in this immutable map, if it can be cheaply computed, -1 otherwise.
The number of elements in this immutable map, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.
Attributes
- Definition Classes
- Source
- Map.scala
Removes a key from this map, returning a new map.
Removes a key from this map, returning a new map.
Value parameters
- key
-
the key to be removed
Attributes
- Returns
-
a new map without a binding for key
- Source
- Map.scala
The size of this immutable map.
The size of this immutable map.
Note: will not terminate for infinite-sized collections.
Attributes
- Returns
-
the number of elements in this immutable map.
- Definition Classes
- Source
- Map.scala
This function transforms all the values of mappings contained in this map with function f.
Creates a new map obtained by updating this map with a given key/value pair.
Creates a new map obtained by updating this map with a given key/value pair.
Type parameters
- V1
-
the type of the added value
Value parameters
- key
-
the key
- value
-
the value
Attributes
- Returns
-
A new map with the new key/value mapping added to this map.
- Source
- Map.scala
Inherited methods
Alias for concat
Appends all elements of this collection to a string builder.
Appends all elements of this collection to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this collection without any separator string.
Example:
scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)
scala> val b = new StringBuilder()
b: StringBuilder =
scala> val h = a.addString(b)
h: StringBuilder = 1234
Value parameters
- b
-
the string builder to which elements are appended.
Attributes
- Returns
-
the string builder
bto which elements were appended. - Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala
Appends all elements of this collection to a string builder using a separator string.
Appends all elements of this collection to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method toString) of all elements of this collection, separated by the string sep.
Example:
scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)
scala> val b = new StringBuilder()
b: StringBuilder =
scala> a.addString(b, ", ")
res0: StringBuilder = 1, 2, 3, 4
Value parameters
- b
-
the string builder to which elements are appended.
- sep
-
the separator string.
Attributes
- Returns
-
the string builder
bto which elements were appended. - Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala
Appends all elements of this map to a string builder using start, end, and separator strings.
Appends all elements of this map to a string builder using start, end, and separator strings. The written text begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this map are separated by the string sep.
Example:
scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)
scala> val b = new StringBuilder()
b: StringBuilder =
scala> a.addString(b , "List(" , ", " , ")")
res5: StringBuilder = List(1, 2, 3, 4)
Value parameters
- b
-
the string builder to which elements are appended.
- end
-
the ending string.
- sep
-
the separator string.
- start
-
the starting string.
Attributes
Composes this partial function with another partial function that gets applied to results of this partial function.
Composes this partial function with another partial function that gets applied to results of this partial function.
Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.
Type parameters
- C
-
the result type of the transformation function.
Value parameters
- k
-
the transformation function
Attributes
- Returns
-
a partial function with the domain of this partial function narrowed by other partial function, which maps arguments
xtok(this(x)). - Inherited from:
- PartialFunction
- Source
- PartialFunction.scala
Composes this partial function with a transformation function that gets applied to results of this partial function.
Composes this partial function with a transformation function that gets applied to results of this partial function.
If the runtime type of the function is a PartialFunction then the other andThen method is used (note its cautions).
Type parameters
- C
-
the result type of the transformation function.
Value parameters
- k
-
the transformation function
Attributes
- Returns
-
a partial function with the domain of this partial function, possibly narrowed by the specified function, which maps arguments
xtok(this(x)). - Definition Classes
- Inherited from:
- PartialFunction
- Source
- PartialFunction.scala
Applies this partial function to the given argument when it is contained in the function domain.
Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.
Note that expression pf.applyOrElse(x, default) is equivalent to
if(pf isDefinedAt x) pf(x) else default(x)
except that applyOrElse method can be implemented more efficiently. For all partial function literals the compiler generates an applyOrElse implementation which avoids double evaluation of pattern matchers and guards. This makes applyOrElse the basis for the efficient implementation for many operations and scenarios, such as:
- combining partial functions into orElse/andThen chains does not lead to excessive apply/isDefinedAt evaluation - lift and unlift do not evaluate source functions twice on each invocation - runWith allows efficient imperative-style combining of partial functions with conditionally applied actions
For non-literal partial function classes with nontrivial isDefinedAt method it is recommended to override applyOrElse with custom implementation that avoids double isDefinedAt evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.
Value parameters
- default
-
the fallback function
- x
-
the function argument
Attributes
Checks whether this instance can possibly equal that.
Checks whether this instance can possibly equal that.
A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.
Value parameters
- that
-
the value being probed for possible equality
Attributes
Builds a new iterable collection by applying a partial function to all elements of this iterable collection on which the function is defined.
Builds a new iterable collection by applying a partial function to all elements of this iterable collection on which the function is defined.
Type parameters
- B
-
the element type of the returned iterable collection.
Value parameters
- pf
-
the partial function which filters and maps the iterable collection.
Attributes
- Returns
-
a new iterable collection resulting from applying the given partial function
pfto each element on which it is defined and collecting the results. The order of the elements is preserved. - Definition Classes
- Inherited from:
- StrictOptimizedIterableOps
- Source
- StrictOptimizedIterableOps.scala
Builds a new collection by applying a partial function to all elements of this map on which the function is defined.
Builds a new collection by applying a partial function to all elements of this map on which the function is defined.
Type parameters
- K2
-
the key type of the returned map.
- V2
-
the value type of the returned map.
Value parameters
- pf
-
the partial function which filters and maps the map.
Attributes
Finds the first element of the collection for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the collection for which the given partial function is defined, and applies the partial function to it.
Note: may not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered.
Value parameters
- pf
-
the partial function
Attributes
- Returns
-
an option value containing pf applied to the first value for which it is defined, or
Noneif none exists. - Example
-
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10) - Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala
Composes another partial function k with this partial function so that this partial function gets applied to results of k.
Composes another partial function k with this partial function so that this partial function gets applied to results of k.
Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.
Type parameters
- R
-
the parameter type of the transformation function.
Value parameters
- k
-
the transformation function
Attributes
- Returns
-
a partial function with the domain of other partial function narrowed by this partial function, which maps arguments
xtothis(k(x)). - Inherited from:
- PartialFunction
- Source
- PartialFunction.scala
Composes two instances of Function1 in a new Function1, with this function applied last.
Composes two instances of Function1 in a new Function1, with this function applied last.
Type parameters
- A
-
the type to which function
gcan be applied
Value parameters
- g
-
a function A => T1
Attributes
- Returns
-
a new function
fsuch thatf(x) == apply(g(x)) - Inherited from:
- Function1
- Source
- Function1.scala
Returns a new iterable collection containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new iterable collection containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the iterable collection is the most specific superclass encompassing the element types of the two operands.
Type parameters
- B
-
the element type of the returned collection.
Value parameters
- suffix
-
the iterable to append.
Attributes
- Returns
-
a new iterable collection which contains all elements of this iterable collection followed by all elements of
suffix. - Inherited from:
- IterableOps
- Source
- Iterable.scala
Returns a new map containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new map containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the map is the most specific superclass encompassing the element types of the two operands.
Value parameters
- suffix
-
the iterable to append.
Attributes
Copy elements to an array, returning the number of elements written.
Copy elements to an array, returning the number of elements written.
Fills the given array xs starting at index start with at most len elements of this collection.
Copying will stop once either all the elements of this collection have been copied, or the end of the array is reached, or len elements have been copied.
Type parameters
- B
-
the type of the elements of the array.
Value parameters
- len
-
the maximal number of elements to copy.
- start
-
the starting index of xs.
- xs
-
the array to fill.
Attributes
- Returns
-
the number of elements written to the array
- Note
-
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array xs starting at index start with values of this collection.
Copying will stop once either all the elements of this collection have been copied, or the end of the array is reached.
Type parameters
- B
-
the type of the elements of the array.
Value parameters
- start
-
the starting index of xs.
- xs
-
the array to fill.
Attributes
- Returns
-
the number of elements written to the array
- Note
-
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array xs starting at index start with values of this collection.
Copying will stop once either all the elements of this collection have been copied, or the end of the array is reached.
Type parameters
- B
-
the type of the elements of the array.
Value parameters
- xs
-
the array to fill.
Attributes
- Returns
-
the number of elements written to the array
- Note
-
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala
Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.
Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.
Note: will not terminate for infinite-sized collections.
Type parameters
- B
-
the type of the elements of
that
Value parameters
- p
-
the test predicate, which relates elements from both collections
- that
-
the other collection
Attributes
- Returns
-
trueif both collections have the same length andp(x, y)istruefor all corresponding elementsxof this iterator andyofthat, otherwisefalse - Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala
Counts the number of elements in the collection which satisfy a predicate.
Counts the number of elements in the collection which satisfy a predicate.
Note: will not terminate for infinite-sized collections.
Value parameters
- p
-
the predicate used to test elements.
Attributes
- Returns
-
the number of elements satisfying the predicate
p. - Inherited from:
- IterableOnceOps
- Source
- IterableOnce.scala