@sheetxl/models
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Models - A Headless javascript spreadsheet library.
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TypeScript
import { ISortedMap, ISortedMapF, SetPairCallback, EditRangeCallback, EditRangeResult } from './interfaces';
/**
* Types that BTree supports by default
*/
export type DefaultComparable = number | string | Date | boolean | null | undefined | (number | string)[] | {
valueOf: () => number | string | Date | boolean | null | undefined | (number | string)[];
};
/**
* Compares DefaultComparables to form a strict partial ordering.
*
* Handles +/-0 and NaN like Map: NaN is equal to NaN, and -0 is equal to +0.
*
* Arrays are compared using '<' and '>', which may cause unexpected equality:
* for example [1] will be considered equal to ['1'].
*
* Two objects with equal valueOf compare the same, but compare unequal to
* primitives that have the same value.
*/
export declare function defaultComparator(a: DefaultComparable, b: DefaultComparable): number;
/**
* Compares items using the < and > operators. This function is probably slightly
* faster than the defaultComparator for Dates and strings, but has not been benchmarked.
* Unlike defaultComparator, this comparator doesn't support mixed types correctly,
* i.e. use it with `BTree<string>` or `BTree<number>` but not `BTree<string|number>`.
*
* NaN is not supported.
*
* Note: null is treated like 0 when compared with numbers or Date, but in general
* null is not ordered with respect to strings (neither greater nor less), and
* undefined is not ordered with other types.
*/
export declare function simpleComparator(a: string, b: string): number;
export declare function simpleComparator(a: number | null, b: number | null): number;
export declare function simpleComparator(a: Date | null, b: Date | null): number;
export declare function simpleComparator(a: (number | string)[], b: (number | string)[]): number;
/**
* A reasonably fast collection of key-value pairs with a powerful API.
* Largely compatible with the standard Map. BTree is a B+ tree data structure,
* so the collection is sorted by key.
*
* B+ trees tend to use memory more efficiently than hashTables such as the
* standard Map, especially when the collection contains a large number of
* items. However, maintaining the sort order makes them modestly slower:
* O(log size) rather than O(1). This B+ tree implementation supports O(1)
* fast cloning. It also supports freeze(), which can be used to ensure that
* a BTree is not changed accidentally.
*
* Confusingly, the ES6 Map.forEach(c) method calls c(value,key) instead of
* c(key,value), in contrast to other methods such as set() and entries()
* which put the key first. I can only assume that the order was reversed on
* the theory that users would usually want to examine values and ignore keys.
* BTree's forEach() therefore works the same way, but a second method
* `.forEachPair((key,value)=>{...})` is provided which sends you the key
* first and the value second; this method is slightly faster because it is
* the "native" for-each method for this class.
*
* Out of the box, BTree supports keys that are numbers, strings, arrays of
* numbers/strings, Date, and objects that have a valueOf() method returning a
* number or string. Other data types, such as arrays of Date or custom
* objects, require a custom comparator, which you must pass as the second
* argument to the constructor (the first argument is an optional list of
* initial items). Symbols cannot be used as keys because they are unordered
* (one Symbol is never "greater" or "less" than another).
*
* @example
* Given a {name: string, age: number} object, you can create a tree sorted by
* name and then by age like this:
*
* let tree = new BTree(undefined, (a, b) => {
* if (a.name > b.name)
* return 1; // Return a number >0 when a > b
* else if (a.name < b.name)
* return -1; // Return a number <0 when a < b
* else // names are equal (or incomparable)
* return a.age - b.age; // Return >0 when a.age > b.age
* });
*
* tree.set({name:"Bill", age:17}, "happy");
* tree.set({name:"Fran", age:40}, "busy & stressed");
* tree.set({name:"Bill", age:55}, "recently laid off");
* tree.forEachPair((k, v) => {
* console.log(`Name: ${k.name} Age: ${k.age} Status: ${v}`);
* });
*
* @description
* The "range" methods (`forEach, forRange, editRange`) will return the number
* of elements that were scanned. In addition, the callback can return {break:R}
* to stop early and return R from the outer function.
*
* - TODO: Test performance of preallocating values array at max size
* - TODO: Add fast initialization when a sorted array is provided to constructor
*
* For more documentation see https://github.com/qwertie/btree-typescript
*
* Are you a C# developer? You might like the similar data structures I made for C#:
* BDictionary, BList, etc. See http://core.loyc.net/collections/
*
* @author David Piepgrass
*/
export default class BTree<K = any, V = any> implements ISortedMapF<K, V>, ISortedMap<K, V> {
private _root;
_size: number;
_maxNodeSize: number;
/**
* provides a total order over keys (and a strict partial order over the type K)
* @returns a negative value if a < b, 0 if a === b and a positive value if a > b
*/
_compare: (a: K, b: K) => number;
/**
* Initializes an empty B+ tree.
* @param compare Custom function to compare pairs of elements in the tree.
* If not specified, defaultComparator will be used which is valid as long as K extends DefaultComparable.
* @param entries A set of key-value pairs to initialize the tree
* @param maxNodeSize Branching factor (maximum items or children per node)
* Must be in range 4..256. If undefined or <4 then default is used; if >256 then 256.
*/
constructor(entries?: [K, V][], compare?: (a: K, b: K) => number, maxNodeSize?: number);
/** Gets the number of key-value pairs in the tree. */
get size(): number;
/** Gets the number of key-value pairs in the tree. */
get length(): number;
/** Returns true iff the tree contains no key-value pairs. */
get isEmpty(): boolean;
/** Releases the tree so that its size is 0. */
clear(): void;
forEach(callback: (v: V, k: K, tree: BTree<K, V>) => void, thisArg?: any): number;
/** Runs a function for each key-value pair, in order from smallest to
* largest key. The callback can return {break:R} (where R is any value
* except undefined) to stop immediately and return R from forEachPair.
* @param onFound A function that is called for each key-value pair. This
* function can return {break:R} to stop early with result R.
* The reason that you must return {break:R} instead of simply R
* itself is for consistency with editRange(), which allows
* multiple actions, not just breaking.
* @param initialCounter This is the value of the third argument of
* `onFound` the first time it is called. The counter increases
* by one each time `onFound` is called. Default value: 0
* @returns the number of pairs sent to the callback (plus initialCounter,
* if you provided one). If the callback returned {break:R} then
* the R value is returned instead. */
forEachPair<R = number>(callback: (k: K, v: V, counter: number) => {
break?: R;
} | void, initialCounter?: number): R | number;
/**
* Finds a pair in the tree and returns the associated value.
* @param defaultValue a value to return if the key was not found.
* @returns the value, or defaultValue if the key was not found.
* @description Computational complexity: O(log size)
*/
get(key: K, defaultValue?: V): V | undefined;
/**
* Adds or overwrites a key-value pair in the B+ tree.
* @param key the key is used to determine the sort order of
* data in the tree.
* @param value data to associate with the key (optional)
* @param overwrite Whether to overwrite an existing key-value pair
* (default: true). If this is false and there is an existing
* key-value pair then this method has no effect.
* @returns true if a new key-value pair was added.
* @description Computational complexity: O(log size)
* Note: when overwriting a previous entry, the key is updated
* as well as the value. This has no effect unless the new key
* has data that does not affect its sort order.
*/
set(key: K, value: V, overwrite?: boolean | SetPairCallback<K, V>): boolean;
/**
* Returns true if the key exists in the B+ tree, false if not.
* Use get() for best performance; use has() if you need to
* distinguish between "undefined value" and "key not present".
* @param key Key to detect
* @description Computational complexity: O(log size)
*/
has(key: K): boolean;
/**
* Removes a single key-value pair from the B+ tree.
* @param key Key to find
* @returns true if a pair was found and removed, false otherwise.
* @description Computational complexity: O(log size)
*/
delete(key: K): boolean;
/** Returns a copy of the tree with the specified key set (the value is undefined). */
with(key: K): BTree<K, V | undefined>;
/** Returns a copy of the tree with the specified key-value pair set. */
with<V2>(key: K, value: V2, overwrite?: boolean): BTree<K, V | V2>;
/** Returns a copy of the tree with the specified key-value pairs set. */
withPairs<V2>(pairs: [K, V | V2][], overwrite: boolean): BTree<K, V | V2>;
/** Returns a copy of the tree with the specified keys present.
* @param keys The keys to add. If a key is already present in the tree,
* neither the existing key nor the existing value is modified.
* @param returnThisIfUnchanged if true, returns this if all keys already
* existed. Performance note: due to the architecture of this class, all
* node(s) leading to existing keys are cloned even if the collection is
* ultimately unchanged.
*/
withKeys(keys: K[], returnThisIfUnchanged?: boolean): BTree<K, V | undefined>;
/** Returns a copy of the tree with the specified key removed.
* @param returnThisIfUnchanged if true, returns this if the key didn't exist.
* Performance note: due to the architecture of this class, node(s) leading
* to where the key would have been stored are cloned even when the key
* turns out not to exist and the collection is unchanged.
*/
without(key: K, returnThisIfUnchanged?: boolean): BTree<K, V>;
/** Returns a copy of the tree with the specified keys removed.
* @param returnThisIfUnchanged if true, returns this if none of the keys
* existed. Performance note: due to the architecture of this class,
* node(s) leading to where the key would have been stored are cloned
* even when the key turns out not to exist.
*/
withoutKeys(keys: K[], returnThisIfUnchanged?: boolean): BTree<K, V>;
/** Returns a copy of the tree with the specified range of keys removed. */
withoutRange(low: K, high: K, includeHigh: boolean, returnThisIfUnchanged?: boolean): BTree<K, V>;
/** Returns a copy of the tree with pairs removed whenever the callback
* function returns false. `where()` is a synonym for this method. */
filter(callback: (k: K, v: V, counter: number) => boolean, returnThisIfUnchanged?: boolean): BTree<K, V>;
/** Returns a copy of the tree with all values altered by a callback function. */
mapValues<R>(callback: (v: V, k: K, counter: number) => R): BTree<K, R>;
/** Performs a reduce operation like the `reduce` method of `Array`.
* It is used to combine all pairs into a single value, or perform
* conversions. `reduce` is best understood by example. For example,
* `tree.reduce((P, pair) => P * pair[0], 1)` multiplies all keys
* together. It means "start with P=1, and for each pair multiply
* it by the key in pair[0]". Another example would be converting
* the tree to a Map (in this example, note that M.set returns M):
*
* let M = tree.reduce((M, pair) => M.set(pair[0],pair[1]), new Map())
*
* **Note**: the same array is sent to the callback on every iteration.
*/
reduce<R>(callback: (previous: R, currentPair: [K, V], counter: number, tree: BTree<K, V>) => R, initialValue: R): R;
reduce<R>(callback: (previous: R | undefined, currentPair: [K, V], counter: number, tree: BTree<K, V>) => R): R | undefined;
/** Returns an iterator that provides items in order (ascending order if
* the collection's comparator uses ascending order, as is the default.)
* @param lowestKey First key to be iterated, or undefined to start at
* minKey(). If the specified key doesn't exist then iteration
* starts at the next higher key (according to the comparator).
* @param reusedArray Optional array used repeatedly to store key-value
* pairs, to avoid creating a new array on every iteration.
*/
entries(lowestKey?: K, reusedArray?: (K | V)[]): IterableIterator<[K, V]>;
/** Returns an iterator that provides items in reversed order.
* @param highestKey Key at which to start iterating, or undefined to
* start at maxKey(). If the specified key doesn't exist then iteration
* starts at the next lower key (according to the comparator).
* @param reusedArray Optional array used repeatedly to store key-value
* pairs, to avoid creating a new array on every iteration.
* @param skipHighest Iff this flag is true and the highestKey exists in the
* collection, the pair matching highestKey is skipped, not iterated.
*/
entriesReversed(highestKey?: K, reusedArray?: (K | V)[], skipHighest?: boolean): IterableIterator<[K, V]>;
private findPath;
/**
* Computes the differences between `this` and `other`.
* For efficiency, the diff is returned via invocations of supplied handlers.
* The computation is optimized for the case in which the two trees have large amounts
* of shared data (obtained by calling the `clone` or `with` APIs) and will avoid
* any iteration of shared state.
* The handlers can cause computation to early exit by returning {break: R}.
* Neither of the collections should be changed during the comparison process (in your callbacks), as this method assumes they will not be mutated.
* @param other The tree to compute a diff against.
* @param onlyThis Callback invoked for all keys only present in `this`.
* @param onlyOther Callback invoked for all keys only present in `other`.
* @param different Callback invoked for all keys with differing values.
*/
diffAgainst<R>(other: BTree<K, V>, onlyThis?: (k: K, v: V) => {
break?: R;
} | void, onlyOther?: (k: K, v: V) => {
break?: R;
} | void, different?: (k: K, vThis: V, vOther: V) => {
break?: R;
} | void): R | undefined;
private static finishCursorWalk;
private static stepToEnd;
private static makeDiffCursor;
/**
* Advances the cursor to the next step in the walk of its tree.
* Cursors are walked backwards in sort order, as this allows them to leverage maxKey() in order to be compared in O(1).
* @param cursor The cursor to step
* @param stepToNode If true, the cursor will be advanced to the next node (skipping values)
* @returns true if the step was completed and false if the step would have caused the cursor to move beyond the end of the tree.
*/
private static step;
/**
* Compares the two cursors. Returns a value indicating which cursor is ahead in a walk.
* Note that cursors are advanced in reverse sorting order.
*/
private static compare;
/** Returns a new iterator for iterating the keys of each pair in ascending order.
* @param firstKey: Minimum key to include in the output. */
keys(firstKey?: K): IterableIterator<K>;
/** Returns a new iterator for iterating the values of each pair in order by key.
* @param firstKey: Minimum key whose associated value is included in the output. */
values(firstKey?: K): IterableIterator<V>;
/** Returns the maximum number of children/values before nodes will split. */
get maxNodeSize(): number;
/** Gets the lowest key in the tree. Complexity: O(log size) */
minKey(): K | undefined;
/** Gets the highest key in the tree. Complexity: O(1) */
maxKey(): K | undefined;
/** Quickly clones the tree by marking the root node as shared.
* Both copies remain editable. When you modify either copy, any
* nodes that are shared (or potentially shared) between the two
* copies are cloned so that the changes do not affect other copies.
* This is known as copy-on-write behavior, or "lazy copying". */
clone(): BTree<K, V>;
/** Performs a greedy clone, immediately duplicating any nodes that are
* not currently marked as shared, in order to avoid marking any
* additional nodes as shared.
* @param force Clone all nodes, even shared ones.
*/
greedyClone(force?: boolean): BTree<K, V>;
/** Gets an array filled with the contents of the tree, sorted by key */
toArray(maxLength?: number): [K, V][];
/** Gets an array of all keys, sorted */
keysArray(): K[];
/** Gets an array of all values, sorted by key */
valuesArray(): V[];
/** Gets a string representing the tree's data based on toArray(). */
toString(): string;
/** Stores a key-value pair only if the key doesn't already exist in the tree.
* @returns true if a new key was added
*/
setIfNotPresent(key: K, value: V): boolean;
/** Returns the next pair whose key is larger than the specified key (or undefined if there is none).
* If key === undefined, this function returns the lowest pair.
* @param key The key to search for.
* @param reusedArray Optional array used repeatedly to store key-value pairs, to
* avoid creating a new array on every iteration.
*/
nextHigherPair(key: K | undefined, reusedArray?: [K, V]): [K, V] | undefined;
/** Returns the next key larger than the specified key, or undefined if there is none.
* Also, nextHigherKey(undefined) returns the lowest key.
*/
nextHigherKey(key: K | undefined): K | undefined;
/** Returns the next pair whose key is smaller than the specified key (or undefined if there is none).
* If key === undefined, this function returns the highest pair.
* @param key The key to search for.
* @param reusedArray Optional array used repeatedly to store key-value pairs, to
* avoid creating a new array each time you call this method.
*/
nextLowerPair(key: K | undefined, reusedArray?: [K, V]): [K, V] | undefined;
/** Returns the next key smaller than the specified key, or undefined if there is none.
* Also, nextLowerKey(undefined) returns the highest key.
*/
nextLowerKey(key: K | undefined): K | undefined;
/** Returns the key-value pair associated with the supplied key if it exists
* or the pair associated with the next lower pair otherwise. If there is no
* next lower pair, undefined is returned.
* @param key The key to search for.
* @param reusedArray Optional array used repeatedly to store key-value pairs, to
* avoid creating a new array each time you call this method.
* */
getPairOrNextLower(key: K, reusedArray?: [K, V]): [K, V] | undefined;
/** Returns the key-value pair associated with the supplied key if it exists
* or the pair associated with the next lower pair otherwise. If there is no
* next lower pair, undefined is returned.
* @param key The key to search for.
* @param reusedArray Optional array used repeatedly to store key-value pairs, to
* avoid creating a new array each time you call this method.
* */
getPairOrNextHigher(key: K, reusedArray?: [K, V]): [K, V] | undefined;
/** Edits the value associated with a key in the tree, if it already exists.
* @returns true if the key existed, false if not.
*/
changeIfPresent(key: K, value: V): boolean;
/**
* Builds an array of pairs from the specified range of keys, sorted by key.
* Each returned pair is also an array: pair[0] is the key, pair[1] is the value.
* @param low The first key in the array will be greater than or equal to `low`.
* @param high This method returns when a key larger than this is reached.
* @param includeHigh If the `high` key is present, its pair will be included
* in the output if and only if this parameter is true. Note: if the
* `low` key is present, it is always included in the output.
* @param maxLength Length limit. getRange will stop scanning the tree when
* the array reaches this size.
* @description Computational complexity: O(result.length + log size)
*/
getRange(low: K, high: K, includeHigh?: boolean, maxLength?: number): [K, V][];
/** Adds all pairs from a list of key-value pairs.
* @param pairs Pairs to add to this tree. If there are duplicate keys,
* later pairs currently overwrite earlier ones (e.g. [[0,1],[0,7]]
* associates 0 with 7.)
* @param overwrite Whether to overwrite pairs that already exist.
* if false pairs[i] is ignored when the key pairs[i][0] already exists.
* if SetPairCallback then this will be called on both inserts and updates.
* @returns The number of pairs added to the collection.
* @description Computational complexity: O(pairs.length * log(size + pairs.length))
*/
setPairs(pairs: [K, V][], overwrite?: boolean | SetPairCallback<K, V>): number;
forRange(low: K, high: K, includeHigh: boolean, onFound?: (k: K, v: V, counter: number) => void, initialCounter?: number): number;
/**
* Added by MTF. To allow for editMode to be passed to forRange.
* @returns
*/
forEditRange<R = number>(low: K, high: K, includeHigh: boolean, editMode: boolean, onFound?: EditRangeCallback<K, V, R>, initialCounter?: number): EditRangeResult<V, R> | number | number;
/**
* Scans and potentially modifies values for a subsequence of keys.
* Note: the callback `onFound` should ideally be a pure function.
* Specifically, it must not insert items, call clone(), or change
* the collection except via return value; out-of-band editing may
* cause an exception or may cause incorrect data to be sent to
* the callback (duplicate or missed items). It must not cause a
* clone() of the collection, otherwise the clone could be modified
* by changes requested by the callback.
* @param low The first key scanned will be greater than or equal to `low`.
* @param high Scanning stops when a key larger than this is reached.
* @param includeHigh If the `high` key is present, `onFound` is called for
* that final pair if and only if this parameter is true.
* @param onFound A function that is called for each key-value pair. This
* function can return `{value:v}` to change the value associated
* with the current key, `{delete:true}` to delete the current pair,
* `{break:R}` to stop early with result R, or it can return nothing
* (undefined or {}) to cause no effect and continue iterating.
* `{break:R}` can be combined with one of the other two commands.
* The third argument `counter` is the number of items iterated
* previously; it equals 0 when `onFound` is called the first time.
* @returns The number of values scanned, or R if the callback returned
* `{break:R}` to stop early.
* @description
* Computational complexity: O(number of items scanned + log size)
* Note: if the tree has been cloned with clone(), any shared
* nodes are copied before `onFound` is called. This takes O(n) time
* where n is proportional to the amount of shared data scanned.
*/
editRange<R = V>(low: K, high: K, includeHigh: boolean, onFound: EditRangeCallback<K, V, R>, initialCounter?: number): R | number;
/** Same as `editRange` except that the callback is called for all pairs. */
editAll<R = V>(onFound: EditRangeCallback<K, V, R>, initialCounter?: number): R | number;
/**
* Removes a range of key-value pairs from the B+ tree.
* @param low The first key scanned will be greater than or equal to `low`.
* @param high Scanning stops when a key larger than this is reached.
* @param includeHigh Specifies whether the `high` key, if present, is deleted.
* @returns The number of key-value pairs that were deleted.
* @description Computational complexity: O(log size + number of items deleted)
*/
deleteRange(low: K, high: K, includeHigh: boolean): number;
/** Deletes a series of keys from the collection. */
deleteKeys(keys: K[]): number;
/** Gets the height of the tree: the number of internal nodes between the
* BTree object and its leaf nodes (zero if there are no internal nodes). */
get height(): number;
/** Makes the object read-only to ensure it is not accidentally modified.
* Freezing does not have to be permanent; unfreeze() reverses the effect.
* This is accomplished by replacing mutator functions with a function
* that throws an Error. Compared to using a property (e.g. this.isFrozen)
* this implementation gives better performance in non-frozen BTrees.
*/
freeze(): void;
/** Ensures mutations are allowed, reversing the effect of freeze(). */
unfreeze(): void;
/** Returns true if the tree appears to be frozen. */
get isFrozen(): boolean;
/** Scans the tree for signs of serious bugs (e.g. this.size doesn't match
* number of elements, internal nodes not caching max element properly...)
* Computational complexity: O(number of nodes), i.e. O(size). This method
* skips the most expensive test - whether all keys are sorted - but it
* does check that maxKey() of the children of internal nodes are sorted. */
checkValid(): void;
}
export declare const DeleteRange: () => {
delete: boolean;
};
export declare const Break: {
break: boolean;
};
/** A BTree frozen in the empty state. */
export declare const EmptyBTree: BTree<any, any>;
//# sourceMappingURL=b+tree.d.ts.map