structurae - npm Package Compare versions

Comparing version 1.1.0 to 1.1.1

index.d.ts

@@ -224,3 +224,2 @@ // Type definitions for structurae
     select(index: number): number;
-    private updateRanks(): void;
     static getLength(size: number): number;
@@ -227,0 +226,0 @@ }

lib/bit-array.js

 /**
+ * Uses Uint32Array as a vector or array of bits.
  *
@@ -36,3 +37,3 @@ * @extends Uint32Array
    * @param {number} index
-   * @param {number} [value]
+   * @param {number} [value=1]
    * @returns {BitArray}
@@ -39,0 +40,0 @@ */

lib/ranked-bit-array.js

@@ -7,3 +7,3 @@ const BitArray = require('./bit-array');
  *
- * @extends Uint16Array
+ * @extends BitArray
  */
@@ -15,3 +15,3 @@ class RankedBitArray extends BitArray {
    * @param {number} index
-   * @param {number} [value]
+   * @param {number} [value=1]
    * @returns {RankedBitArray}
@@ -21,3 +21,6 @@ */
     super.setBit(index, value);
-    this.updateRanks(this.lastPosition.bucket, value || -1);
+    const change = value || -1;
+    for (let i = (this.length >> 1) + this.lastPosition.bucket; i < this.length; i++) {
+      this[i] += change;
+    }
     return this;
@@ -36,14 +39,2 @@ }
   /**
-   * @private
-   * @param {number} bucket
-   * @param {number} value
-   * @returns {void}
-   */
-  updateRanks(bucket, value) {
-    for (let i = (this.length >> 1) + bucket; i < this.length; i++) {
-      this[i] += value;
-    }
-  }
-
-  /**
    * Returns the rank of a bit at a given index.
@@ -50,0 +41,0 @@ *

lib/record-array.js

@@ -238,4 +238,3 @@ /**
   getByteOffset(index, field) {
-    const { offset, offsets } = this;
-    return (index << offset) + offsets[field];
+    return (index << this.offset) + this.offsets[field];
   }
@@ -268,2 +267,26 @@
   /**
+   * Stores a given object as a record at a given index.
+   *
+   * @param {number} index the index of the record
+   * @param {Object} object the object to be stored
+   * @returns {RecordArray}
+   * @example
+   * const people = new RecordArray([
+   *   { name: 'age', type: 'Uint8' },
+   *   { name: 'score', type: 'Float32' },
+   * ], 20);
+   *
+   * person.set(0, 'age', 10).set(0, 'score', 5.0).toObject(0);
+   * //=> { age: 10, score: 5.0 }
+   */
+  fromObject(index, object) {
+    const { fields } = this;
+    for (let i = 0; i < fields.length; i++) {
+      const { name } = fields[i];
+      if (Reflect.has(object, name)) this.set(index, name, object[name]);
+    }
+    return this;
+  }
+
+  /**
    * Returns the length of underlying ArrayBuffer required to hold the given amount of records.
@@ -270,0 +293,0 @@ *

package.json

 {
   "name": "structurae",
-  "version": "1.1.0",
+  "version": "1.1.1",
   "description": "Data structures for performance-sensitive modern JavaScript applications.",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

@@ -11,4 +11,4 @@ # Structurae
     - [BitField](https://github.com/zandaqo/structurae#BitField) - stores and operates on data in Numbers and BigInts treating them as bitfields.
-    - BitArray - an array of bits implemented with Uint32Array.
-    - RankedBitArray - extends BitArray with O(1) time rank and O(logN) select methods.
+    - [BitArray](https://github.com/zandaqo/structurae#BitArray) - an array of bits implemented with Uint32Array.
+    - [RankedBitArray](https://github.com/zandaqo/structurae#RankedBitArray) - extends BitArray with O(1) time rank and O(logN) select methods.
 - [Graphs](https://github.com/zandaqo/structurae#Graphs):
@@ -40,2 +40,3 @@ - [Graph](https://github.com/zandaqo/structurae#Graph) -  extends an adjacency list/matrix structure and provides methods for traversal (BFS, DFS),
     - [Structurae: Data Structures for Heigh-Performance JavaScript](https://blog.usejournal.com/structurae-data-structures-for-high-performance-javascript-9b7da4c73f8)
+    - [Structurae 1.0: Graphs, Strings, and WebAssembly](https://medium.com/@zandaqo/structurae-1-0-graphs-strings-and-webassembly-25dd964d5a70)
 
@@ -205,2 +206,37 @@ ## Overview
 
+### BitArray
+BitArray uses Uint32Array as an array or vector of bits. It's a simpler version of BitField that only sets and checks individual bits:
+
+```javascript
+const array = new BitArray(10);
+array.getBit(0)
+//=> 0
+array.setBit(0).getBit(0);
+//=> 1
+array.size
+//=> 10
+array.length
+//=> 1
+```
+
+BitArray is the base class for [Pool](https://github.com/zandaqo/structurae#Pool) and [RankedBitArray](https://github.com/zandaqo/structurae#RankedBitArray) classes. 
+It's useful in cases where one needs more bits than can be stored in a number, but doesn't want to use BigInts as it is done by [BitField](https://github.com/zandaqo/structurae#BitField).
+
+### RankedBitArray
+RankedBitArray is an extension of BitArray with methods to efficiently calculate rank and select. 
+The rank is calculated in constant time where as select has O(logN) time complexity.
+This is often used as a basic element in implementing succinct data structures.
+
+```javascript
+const array = new RankedBitArray(10);
+array.setBit(1).setBit(3).setBit(7);
+array.rank(2);
+//=> 1
+array.rank(7);
+//=> 2
+array.select(2);
+//=> 3
+```
+
+
 ### Graphs
@@ -500,2 +536,6 @@ Structurae offers classes that implement Adjacency List (`UnweightedAdjacencyList`, `WeightedAdjacencyList`) and Adjacency Matrix (`UnweightedAdjacencyMatrix`,
 //=> { age: 10, score: 5.0, name: '' }
+// populate record from an object
+people.fromObject(0, { age: 15, score: 6.0, name: ''})
+people.toObject(0);
+//=> { age: 15, score: 6.0, name: '' }
 ```
@@ -502,0 +542,0 @@

No alert changes

Improved metrics

Total package byte prevSize

158528

increased by1.87%

Number of package files

24

increased by4.35%

Lines of code

4370

increased by0.32%

Number of lines in readme file

736

increased by5.75%

No dependency changes