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package @rimbu/common

The @rimbu/common package provides many commonly used types and utilities that can also be of use to Rimbu users.

Interfaces

NameDescription
Comp<K>An object providing methods to compare two values of type K.
ToJSON<V,D>Utility type to convert some object to a JSON serializable format.
TraverseStateAn object used to track the state of a traversal, e.g. a forEach.

Namespaces

NameDescription
AsyncOptLazyA potentially lazy and/or asynchronous value of type T.
AsyncReducerAn AsyncReducer is a stand-alone asynchronous calculation that takes input values of type I, and, when requested, produces an output value of type O.
CollectFunA function used in collect methods to collect values from a collection. This is basically a single-pass map and filter.
CompAn object providing methods to compare two values of type K.
EqA function returning true if given v1 and v2 should be considered equal.
ErrBaseundocumented
IndexRangeA flexible range specification for numeric indices. If a start or end is defined, a tuple can be used where the second item is a boolean indicating whether that end is inclusive or exclusive.

An IndexRange can have one of the following forms:

  • { amount: number }
  • { start: number }
  • { start: number, amount: number }
  • { start: number, end: number }
  • { start: number, end: [number, boolean] }
  • { start: [number, boolean] }
  • { start: [number, boolean], amount: number }
  • { start: [number, boolean], end: number }
  • { start: [number, boolean], end: [number, boolean] }
  • { end: number }
  • { end: [number, boolean] } | | Range_2 | A range definition for any type of (orderable) value. If a start or end is defined, a tuple can be used where the second item is a boolean indicating whether that end is inclusive (true) or exclusive (false). A Range of type T can have one of the following forms:
  • { end: T }
  • { end: [T, boolean] }
  • { start: T }
  • { start: T, end: T }
  • { start: T, end: [T, boolean] }
  • { start: [T, boolean] }
  • { start: [T, boolean], end: T }
  • { start: [T, boolean], end: [T, boolean] } | | Reducer | A Reducer is a stand-alone calculation that takes input values of type I, and, when requested, produces an output value of type O. |

Functions

Err

Throws an Err.ForcedError error when called.

Definition

export declare function Err(): never;

example
const emptyMap = HashMap.empty<number, string>()
emptyMap.get(5, Err);
// throws: Err.CustomError(message: 'Err: forced to throw error')

OptLazy

Returns the value contained in an OptLazy instance of type T.

Definition

export declare function OptLazy<T>(optLazy: OptLazy<T>): T;

Type parameters
NameDescription
T

Parameters

NameTypeDescription
optLazyOptLazy<T>the OptLazy value of type T
example
OptLazy(1)              // => 1
OptLazy(() => 1) // => 1
OptLazy(() => () => 1) // => () => 1

OptLazyOr

Returns the value contained in an OptLazyOr instance of type T, or the given otherValue if the lazy function returns it.

Definition

export declare function OptLazyOr<T, O>(optLazyOr: OptLazyOr<T, O>, otherValue: O): T | O;

Type parameters
NameDescription
T
O

Parameters

NameTypeDescription
optLazyOrOptLazyOr<T, O>a value or a function returning a value or otherwise the received value
otherValueOthe value to return if the optLazyOr does not return its own value
example
OptLazyOr(1, 'a')               // => 1
OptLazyOr(() => 1, 'a') // => 1
OptLazyOr((none) => none, 'a') // => 'a'

TraverseState

Returns a new TraverseState instance, using optionally given startIndex as a start index value.

Definition

export declare function TraverseState(startIndex?: number): TraverseState;

Parameters

NameTypeDescription
startIndexnumber(default: 0) the start index to use

Update

Returns the result of given update parameter, where it can either directly give a new value, or it is a function receiving the given value, and returns a new value.

Definition

export declare function Update<T>(value: T, update: Update<T>): T;

Type parameters
NameDescription
T

Parameters

NameTypeDescription
valueTthe current value
updateUpdate<T>an Update value, either a new value or a function receiving the old value and returning a new one.
example
Update(1, 2)          // => 2
Update(1, () => 10) // => 10
Update(1, v => v + 1) // => 2