StringBuilder for Node.js
An easy and fast in-memory string builder for Node.js.
const StringBuilder = require("node-stringbuilder");
const sb = new StringBuilder("Hi");
sb.appendLine(",").append("This is a simple example demonstrating how to use this module.");
console.log(sb.toString()); // Hi,
// This is a simple example demonstrating how to use this module.
sb.insert("Text can be added into any position of this builder.");
sb.replace(53, 118, "Or replace the existing text.");
console.log(sb.toString()); // Text can be added into any position of this builder.HOr replace the existing text.
sb.deleteCharAt(52).insert(52, " ");
console.log(sb.toString()); // Text can be added into any position of this builder. Or replace the existing text.
sb.toLowerCase().replaceAll("text", "string");
console.log(sb.toString()); // string can be added into any position of this builder. or replace the existing string.
console.log(sb.clone().reverse().toString()); // .gnirts gnitsixe eht ecalper ro .redliub siht fo noitisop yna otni dedda eb nac gnirts
console.log(sb.toString(0, 19)); // string can be added
console.log(sb.length()); // 86
console.log(sb.count()); // 15
console.log(sb.indexOf("is")); // Uint32Array [ 43, 72 ]
console.log(sb.indexOfSkip("is")); // Uint32Array [ 43, 72 ]
console.log(sb.lastIndexOf("is")); // Uint32Array [ 72, 43 ]
console.log(sb.indexOfRegExp(/is/g)); // { index: [ 43, 72 ], lastIndex: [ 45, 74 ] }
console.log(sb.repeat().indexOf("is")); // Uint32Array [ 43, 72, 129, 158 ]
sb.substring(11, 37);
console.log(sb.toString()); // be added into any position
console.log(sb.equalsIgnoreCase("be Added into Any position")); // true
console.log(sb.toBuffer()); // UTF-8 encoded
- Implemented with N-API.
- Operating strings in a scalable buffer.
- Multiple types of data are allowed to input.
- Strings
- Buffers(UTF-8 encoded)
- Instances of this StringBuilder module
- ReadStream(to read file)
- Numbers, booleans, other objects
- Fast string search algorithm(Boyer-Moore-MagicLen)
- Clonable
Import this module by using require function.
const StringBuilder = require('node-stringbuilder');
Use new operator or from function to create a StringBuilder instance.
const sb1 = new StringBuilder();
// or
const sb2 = StringBuilder.from();
When creating an instance of StringBuilder, you can initialize the text and capacity.
const sb = StringBuilder.from("First", 4096);
By default, a block of buffer space used by StringBuilder is 128 characters. The space of the buffer can be expanded or shrinked by blocks.
// To expand
const newCapacity = 65536;
sb.expandCapacity(newCapacity);
// To shrink
sb.shrinkCapacity();
If some text are added into StringBuilder, StringBuilder will check its space. And if the space is too small, it will re-alloc a bigger one automatically. This re-allocation has overheads, if it does this frequently, your program may be slowed down. Therefore, if you can predict the length of your text, please set the capacity when creating a StringBuilder instance.
Concat text.
sb.append("string").append(123).append(false).append(fs.createReadStream(path));
Add a new line after append.
sb.appendLine("string");
Append text repeatedly.
sb.appendRepeat("string", 3);
Append a file asynchronizely.
await sb.appendReadStream(fs.createReadStream(path));
Insert text to any position.
sb.insert("string"); // To the head.
sb.insert(5, "string");
Replace text to the position in a range of index.
sb.replace(4, 15, "string");
Replace existing substrings to another.
sb.replacePattern("old", "new");
sb.replacePattern(
"old",
"new",
offset,
limit
);
Replace all existing substrings to another.
sb.replaceAll("old", "new");
Delete text from a range of index.
sb.delete(4, 15);
Delete a character at a index.
sb.deleteCharAt(4);
Clear all text, but preserve the capacity.
sb.clear();
Reserve text in a range of index.
sb.substring(1, 5); // input the start and end index
sb.substr(1, 5); // input the start index and length
Reverse text.
sb.reverse();
Convert text to upper or lower case.
sb.upperCase();
sb.lowerCase();
Remove any leading and trailing whitespace.
sb.trim();
Repeat current text for specific count.
sb.repeat(1);
Expand the capacity of this StringBuilder.
sb.expandCapacity(4096).append("string");
Expand and get the updated capacity,
const capacity = sb.expandCapacity(4096, true);
Shrink the capacity of this StringBuilder.
sb.shrinkCapacity().clone().append("string");
Shrink and get the updated capacity,
const capacity = sb.shrinkCapacity(true);
To get the length of this StringBuilder,
const length = sb.length();
To get the length of this StringBuilder,
const capacity = sb.capacity();
To count the words,
const words = sb.count();
Build a string of a specific range of index.
const str = sb.toString(4, 10);
Build a UTF-8 buffer of a specific range of index.
const buffer = sb.toBuffer(4, 10);
To get the full text,
const text = sb.toString();
const buffer = sb.toBuffer();
To get one character at a specific index,
const c = sb.charAt(4);
Search substrings from the head,
const indexArray = sb.indexOf("string");
const indexArray2 = sb.indexOf("string", offset, limit);
Search substrings from the head by using RegExp,
var indexArray = sb.indexOf(/string/g);
Search substrings from the end,
const indexArray = sb.lastIndexOf("string");
Determine whether the two strings are the same.
const equal = sb.equals("string");
To ignore the case of letters,
const equal = sb.equalsIgnoreCase("string");
Determine whether it starts or ends with a specific pattern.
const start = sb.startsWith("string");
const end = sb.endsWith("string");
RegExp is not supported in startsWith and endsWith methods.
Clone this StringBuilder.
const newSB = sb.clone();
To run the test suite, first install the dependencies, then run npm test:
npm install
npm test
To run the benchmark suite, first install the dependencies, then run npm run benchmark:
npm install
npm run benchmark
Here is my result,
Append
- 43 milliseconds
✓ Natively append text 1000000 times (43ms)
- 567 milliseconds
✓ Use StringBuilder to append text 1000000 times (567ms)
- 1278 milliseconds
✓ Use StringBuilder to insert text 1000000 times at the end (1287ms)
- 17 milliseconds
✓ Use StringBuilder to append text 1000000 times repeatly
Insert
- 92 milliseconds
✓ Natively insert text 10000 times (92ms)
- 10 milliseconds
✓ Use StringBuilder to insert text 10000 times
Delete
- 1427 milliseconds
✓ Natively delete text 5000 times (1429ms)
- 87 milliseconds
✓ Use StringBuilder to delete text 5000 times (88ms)
Replace
- 1511 milliseconds
✓ Natively replace text 5000 times (1513ms)
- 85 milliseconds
✓ Use StringBuilder to replace text 5000 times (86ms)
Replace Pattern
- 37 milliseconds
✓ Natively replace text with the same length by using a RegExp pattern
- 20 milliseconds
✓ Use StringBuilder to replace text with the same length by using a pattern
- 35 milliseconds
✓ Natively replace text by using a RegExp pattern
- 29 milliseconds
✓ Use StringBuilder to replace text by using a pattern
Equals
- 2 milliseconds
✓ Natively check the equal 50000 times
- 13 milliseconds
✓ Use StringBuilder to check the equal 50000 times
EqualsIgnoreCase
- 21 milliseconds
✓ Natively check the equal 50000 times
- 19 milliseconds
✓ Use StringBuilder to check the equal 50000 times
IndexOf
- 65 milliseconds
✓ Natively search text (65ms)
- 2 milliseconds
✓ Use StringBuilder to search text
Reverse
- 516 milliseconds
✓ Natively reverse text (516ms)
- 14 milliseconds
✓ Use StringBuilder to reverse text
According to the result of benchmark, if you just want to append a few different strings, please append them by using native operator + instead of this module.
MIT