website/docs/Seq.Set.mdx
import Repl from '@/repl/Repl.tsx'; import CodeLink from '@/mdx-components/CodeLink.tsx';
<CodeLink to="../Seq" /> which represents a set of values.
<Signature code="type Seq.Set<T> extends Seq<T, T>, Collection.Set<T>" />Because <CodeLink to="../Seq" /> are often lazy, Seq.Set does not provide the same guarantee
of value uniqueness as the concrete <CodeLink to="../Set" />.
Always returns a Seq.Set, discarding associated indices or keys.
<Signature code="Seq.Set<T>(collection?: Iterable<T> | ArrayLike<T>): Seq.Set<T>" />Note: Seq.Set is a conversion function and not a class, and does not use the new keyword during construction.
Returns a Seq.Set of the provided values.
<Signature code="Seq.Set.of<T>(...values: Array<T>): Seq.Set<T>" />Returns a new Seq.Set with values passed through a mapper function.
<Signature
code={map<M>(mapper: (value: T, key: T, iter: this) => M, context?: unknown): Set<M>}
/>
<Repl defaultValue={Seq.Set([ 1, 2 ]).map(x => 10 * x)} />
Note: map() always returns a new instance, even if it produced the same value at every step.
Flat-maps the Seq, returning a Seq of the same type.
Similar to set.map(...).flatten(true).
<Signature
code={flatMap<M>(mapper: (value: T, key: T, iter: this) => Iterable<M>, context?: unknown): Seq.Set<M>}
/>
Returns a new Set with only the values for which the predicate function returns true.
Note: filter() always returns a new instance, even if it results in not filtering out any values.
<Signature
code={filter(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): Seq.Set<T>}
/>
Returns a new Set with only the values for which the predicate function returns false.
<Signature
code={filterNot(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): Seq.Set<T>}
/>
Note: filterNot() always returns a new instance, even if it results in not filtering out any values.
Returns a new Set with the values for which the predicate function returns false and another for which is returns true.
<Signature
code={partition(predicate: (this: C, value: T, key: T, iter: this) => boolean, context?: C): [Seq.Set<T>, Seq.Set<T>]}
/>
Returns a new Collection of the same type which includes the same entries, stably sorted by using a comparator.
<Signature code={sort(comparator?: Comparator<T>): OrderedSet<T>} />
If a comparator is not provided, a default comparator uses < and >.
comparator(valueA, valueB):
0 if the elements should not be swapped.-1 (or any negative number) if valueA comes before valueB1 (or any positive number) if valueA comes after valueBPairSorting enum typeNote: sort() Always returns a new instance, even if the original was already sorted.
Note: This is always an eager operation.
<MemberLabel label="sortBy()" />Like sort, but also accepts a comparatorValueMapper which allows for sorting by more sophisticated means:
<Signature
code={sortBy<C>(comparatorValueMapper: (value: T, key: T, iter: this) => C, comparator?: Comparator<C>): this & OrderedSet<T>}
/>
<Repl
defaultValue={Seq.Set([ { name: 'Bob', age: 30 }, { name: 'Max', age: 25 }, { name: 'Lili', age: 35 } ]).sortBy(person => person.age)}
/>
Note: sortBy() Always returns a new instance, even if the original was already sorted.
Note: This is always an eager operation.
<MemberLabel label="reverse()" />Returns a new Set with the order of the values reversed.
<Signature code={reverse(): Set<T>} />
Returns a Map of Set, grouped by the return value of the grouper function.
<Signature
code={groupBy<G>(grouper: (value: T, key: T, iter: this) => G, context?: unknown): Map<G, Set<T>>}
/>
Note: This is not a lazy operation.
Deeply converts this Set Seq to equivalent native JavaScript Array.
<Signature code={toJS(): Array<DeepCopy<T>>} />
Shallowly converts this Set Seq to equivalent native JavaScript Array.
<Signature code={toJSON(): Array<T>} />
Shallowly converts this collection to an Array.
<Signature code={toArray(): Array<T>} />
Shallowly converts this Collection to an Object.
<Signature code={toObject(): { [key: string]: T }} />
Converts keys to Strings.
Returns itself.
<Signature code={toSeq(): Seq.Set<T>} />
Returns a Seq.Keyed from this Collection where indices are treated as keys.
This is useful if you want to operate on a Collection and preserve the [value, value] pairs.
<Signature code={toKeyedSeq(): Seq.Keyed<T, T>} />
Returns an Seq.Indexed of the values of this Collection, discarding keys.
<Signature code={toIndexedSeq(): Seq.Indexed<T>} />
Returns a Seq.Set of the values of this Collection, discarding keys.
<Signature code={toSetSeq(): Seq.Set<T>} />
True if this and the other Collection have value equality, as defined by Immutable.is().
<Signature code={equals(other): boolean} />
Note: This is equivalent to Immutable.is(this, other), but provided to allow for chained expressions.
Computes and returns the hashed identity for this Collection.
The hashCode of a Collection is used to determine potential equality, and is used when adding this to a Set or as a key in a Map, enabling lookup via a different instance.
<Signature code={hashCode(): number} />
<Repl
defaultValue={const a = Set([ 1, 2, 3 ]); const b = Set([ 1, 2, 3 ]); assert.notStrictEqual(a, b); // different instances const set = Set([ a ]); assert.equal(set.has(b), true);}
/>
If two values have the same hashCode, they are not guaranteed to be equal. If two values have different hashCodes, they must not be equal.
Returns the value associated with the provided key, or notSetValue if the Collection does not contain this key.
Note: it is possible a key may be associated with an undefined value, so if notSetValue is not provided and this method returns undefined, that does not guarantee the key was not found.
<Signature
code={get<NSV>(key: T, notSetValue: NSV): T | NSV get(key: T): T | undefined}
/>
True if a key exists within this Collection, using Immutable.is to determine equality.
<Signature code={has(key: T): boolean} />
True if a value exists within this Collection, using Immutable.is to determine equality.
<Signature code={includes(value: T): boolean} />
Returns the first value in this Collection.
<Signature
code={first<NSV>(notSetValue: NSV): T | NSV first(): T | undefined}
/>
Returns the last value in this Collection.
<Signature
code={last<NSV>(notSetValue: NSV): T | NSV last(): T | undefined}
/>
Returns the value found by following a path of keys or indices through nested Collections.
<Signature
code={getIn(searchKeyPath: Iterable<unknown>, notSetValue?: unknown): unknown}
/>
<Repl
defaultValue={const deepSet = Set([Set([1, 2, 3])]); deepSet.getIn([0, 1])}
/>
Plain JavaScript Object or Arrays may be nested within an Immutable.js Collection, and getIn() can access those values as well:
<Repl
defaultValue={const deepSet = Set([{ a: 1, b: 2 }]); deepSet.getIn([0, 'b'])}
/>
True if the result of following a path of keys or indices through nested Collections results in a set value.
<Signature code={hasIn(searchKeyPath: Iterable<unknown>): boolean} />
Converts this Collection to a Map, Throws if keys are not hashable.
<Signature code={toMap(): Map<T, T>} />
Note: This is equivalent to Map(this.toKeyedSeq()), but provided for convenience and to allow for chained expressions.
Converts this Collection to a Map, maintaining the order of iteration.
<Signature code={toOrderedMap(): OrderedMap<T, T>} />
Note: This is equivalent to OrderedMap(this.toKeyedSeq()), but provided for convenience and to allow for chained expressions.
Returns itself.
<Signature code={toSet(): Set<T>} />
Converts this Collection to a Set, maintaining the order of iteration.
<Signature code={toOrderedSet(): OrderedSet<T>} />
Note: This is equivalent to OrderedSet(this), but provided for convenience and to allow for chained expressions.
Converts this Collection to a List.
<Signature code={toList(): List<T>} />
Converts this Collection to a Stack, discarding keys. Throws if values are not hashable.
<Signature code={toStack(): Stack<T>} />
Note: This is equivalent to Stack(this), but provided to allow for chained expressions.
An iterator of this Set's keys.
<Signature code={keys(): IterableIterator<T>} />
Note: this will return an ES6 iterator which does not support Immutable.js sequence algorithms. Use keySeq instead, if this is what you want.
An iterator of this Set's values.
<Signature code={values(): IterableIterator<T>} />
Note: this will return an ES6 iterator which does not support Immutable.js sequence algorithms. Use valueSeq instead, if this is what you want.
An iterator of this Set's entries as [value, value] tuples.
<Signature code={entries(): IterableIterator<[T, T]>} />
Note: this will return an ES6 iterator which does not support Immutable.js sequence algorithms. Use entrySeq instead, if this is what you want.
Returns a new Seq.Indexed of the keys of this Collection, discarding values.
<Signature code={keySeq(): Seq.Indexed<T>} />
Returns an Seq.Indexed of the values of this Collection, discarding keys.
<Signature code={valueSeq(): Seq.Indexed<T>} />
Returns a new Seq.Indexed of [value, value] tuples.
<Signature code={entrySeq(): Seq.Indexed<[T, T]>} />
The sideEffect is executed for every entry in the Collection.
<Signature
code={forEach(sideEffect: (value: T, key: T, iter: this) => unknown, context?: unknown): number}
/>
Unlike Array#forEach, if any call of sideEffect returns false, the iteration will stop. Returns the number of entries iterated (including the last iteration which returned false).
Returns a new Set of the same type representing a portion of this Set from start up to but not including end.
<Signature code={slice(begin?: number, end?: number): Set<T>} />
If begin is negative, it is offset from the end of the Collection. e.g. slice(-2) returns a Collection of the last two entries. If it is not provided the new Collection will begin at the beginning of this Collection.
If end is negative, it is offset from the end of the Collection. e.g. slice(0, -1) returns a Collection of everything but the last entry. If it is not provided, the new Collection will continue through the end of this Collection.
If the requested slice is equivalent to the current Collection, then it will return itself.
<MemberLabel label="rest()" />Returns a new Collection of the same type containing all entries except the first.
<Signature code={rest(): Set<T>} />
Returns a new Collection of the same type containing all entries except the last.
<Signature code={butLast(): Set<T>} />
Returns a new Collection of the same type which excludes the first amount entries from this Collection.
<Signature code={skip(amount: number): Set<T>} />
Returns a new Collection of the same type which excludes the last amount entries from this Collection.
<Signature code={skipLast(amount: number): Set<T>} />
Returns a new Collection of the same type which includes entries starting from when predicate first returns false.
<Signature
code={skipWhile(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): Set<T>}
/>
<Repl
defaultValue={Set([ 'dog', 'frog', 'cat', 'hat', 'god' ]) .skipWhile(x => x.match(/g/))}
/>
Returns a new Collection of the same type which includes entries starting from when predicate first returns true.
<Signature
code={skipUntil(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): Set<T>}
/>
<Repl
defaultValue={Set([ 'dog', 'frog', 'cat', 'hat', 'god' ]) .skipUntil(x => x.match(/hat/))}
/>
Returns a new Collection of the same type which includes the first amount entries from this Collection.
<Signature code={take(amount: number): Set<T>} />
Returns a new Collection of the same type which includes the last amount entries from this Collection.
<Signature code={takeLast(amount: number): Set<T>} />
Returns a new Collection of the same type which includes entries from this Collection as long as the predicate returns true.
<Signature
code={takeWhile(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): Set<T>}
/>
<Repl
defaultValue={Set([ 'dog', 'frog', 'cat', 'hat', 'god' ]) .takeWhile(x => x.match(/o/))}
/>
Returns a new Collection of the same type which includes entries from this Collection as long as the predicate returns false.
<Signature
code={takeUntil(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): Set<T>}
/>
<Repl
defaultValue={Set([ 'dog', 'frog', 'cat', 'hat', 'god' ]) .takeUntil(x => x.match(/at/))}
/>
Returns a new Seq with other collections concatenated to this one.
<Signature
code={concat<C>(...valuesOrCollections: Array<Iterable<C> | C>): Seq.Set<T | C>}
/>
Flattens nested Collections.
Will deeply flatten the Collection by default, returning a Collection of the same type, but a depth can be provided in the form of a number or boolean (where true means to shallowly flatten one level). A depth of 0 (or shallow: false) will deeply flatten.
Flattens only others Collection, not Arrays or Objects.
<Signature
code={flatten(depth?: number): this flatten(shallow?: boolean): this}
/>
Flat-maps the Set, returning a new Set.
Similar to set.map(...).flatten(true).
<Signature
code={flatMap<M>(mapper: (value: T, key: T, iter: this) => Iterable<M>, context?: unknown): Set<M>}
/>
Reduces the Iterable to a value by calling the reducer for every entry in the Iterable and passing along the reduced value.
<Signature
code={reduce<R>(reducer: (reduced: R, value: T, key: T, iter: this) => R, initialValue: R): R}
/>
If initialValue is not provided, the first entry in the Iterable will be used as the initial value.
<MemberLabel label="reduceRight()" />Reduces the Iterable to a value by calling the reducer for every entry in the Iterable and passing along the reduced value.
<Signature
code={reduceRight<R>(reducer: (reduced: R, value: T, key: T, iter: this) => R, initialValue: R): R}
/>
Note: Similar to this.reverse().reduce(), and provided for parity with Array#reduceRight.
Returns true if the predicate returns true for every entry in the Iterable.
<Signature
code={every(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): boolean}
/>
Returns true if the predicate returns true for any entry in the Iterable.
<Signature
code={some(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): boolean}
/>
Returns a string of all the entries in the Iterable, separated by separator.
<Signature code={join(separator?: string): string} />
Returns true if the Iterable is empty.
<Signature code={isEmpty(): boolean} />
Returns the number of entries in the Iterable.
<Signature code={count(): number} />
Returns a Map of the number of occurrences of each value in the Iterable.
<Signature
code={countBy<G>(grouper: (value: T, key: T, iter: this) => G, context?: unknown): Map<G, number>}
/>
Returns the first value for which the predicate returns true.
<Signature
code={find(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown, notSetValue?: T): T | undefined}
/>
Returns the last value for which the predicate returns true.
<Signature
code={findLast(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown, notSetValue?: T): T | undefined}
/>
Note: predicate will be called for each entry in reverse.
Returns the first [value, value] entry for which the predicate returns true.
<Signature
code={findEntry(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown, notSetValue?: T): [T, T] | undefined}
/>
Returns the last [value, value] entry for which the predicate returns true.
<Signature
code={findLastEntry(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown, notSetValue?: T): [T, T] | undefined}
/>
Note: predicate will be called for each entry in reverse.
Returns the first key for which the predicate returns true.
<Signature
code={findKey(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): T | undefined}
/>
Returns the last key for which the predicate returns true.
<Signature
code={findLastKey(predicate: (value: T, key: T, iter: this) => boolean, context?: unknown): T | undefined}
/>
Note: predicate will be called for each entry in reverse.
Returns the key associated with the search value, or undefined.
<Signature code={keyOf(searchValue: T): T | undefined} />
Returns the last key associated with the search value, or undefined.
<Signature code={lastKeyOf(searchValue: T): T | undefined} />
Returns the maximum value in this collection. If any values are comparatively equivalent, the first one found will be returned.
<Signature code={max(comparator?: Comparator<T>): T | undefined} />
The comparator is used in the same way as Collection#sort. If it is not provided, the default comparator is >.
When two values are considered equivalent, the first encountered will be returned. Otherwise, max will operate independent of the order of input as long as the comparator is commutative. The default comparator > is commutative only when types do not differ.
If comparator returns 0 and either value is NaN, undefined, or null, that value will be returned.
Like max, but also accepts a comparatorValueMapper which allows for comparing by more sophisticated means:
<Signature
code={maxBy<C>(comparatorValueMapper: (value: T, key: T, iter: this) => C, comparator?: Comparator<C>): T | undefined}
/>
<Repl
defaultValue={Set([ { name: 'Bob', age: 30 }, { name: 'Max', age: 25 }, { name: 'Lili', age: 35 } ]).maxBy(person => person.age)}
/>
Returns the minimum value in this collection. If any values are comparatively equivalent, the first one found will be returned.
<Signature code={min(comparator?: Comparator<T>): T | undefined} />
The comparator is used in the same way as Collection#sort. If it is not provided, the default comparator is <.
When two values are considered equivalent, the first encountered will be returned. Otherwise, min will operate independent of the order of input as long as the comparator is commutative. The default comparator < is commutative only when types do not differ.
If comparator returns 0 and either value is NaN, undefined, or null, that value will be returned.
Like min, but also accepts a comparatorValueMapper which allows for comparing by more sophisticated means:
<Signature
code={minBy<C>(comparatorValueMapper: (value: T, key: T, iter: this) => C, comparator?: Comparator<C>): T | undefined}
/>
<Repl
defaultValue={Set([ { name: 'Bob', age: 30 }, { name: 'Max', age: 25 }, { name: 'Lili', age: 35 } ]).minBy(person => person.age)}
/>
True if iter includes every value in this Collection.
<Signature code={isSubset(iter: Iterable<T>): boolean} />
True if this Collection includes every value in iter.
<Signature code={isSuperset(iter: Iterable<T>): boolean} />