mathjs
Version:
Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with dif
53 lines (39 loc) • 894 B
JavaScript
const {PassThrough: PassThroughStream} = require('stream');
module.exports = options => {
options = {...options};
const {array} = options;
let {encoding} = options;
const isBuffer = encoding === 'buffer';
let objectMode = false;
if (array) {
objectMode = !(encoding || isBuffer);
} else {
encoding = encoding || 'utf8';
}
if (isBuffer) {
encoding = null;
}
const stream = new PassThroughStream({objectMode});
if (encoding) {
stream.setEncoding(encoding);
}
let length = 0;
const chunks = [];
stream.on('data', chunk => {
chunks.push(chunk);
if (objectMode) {
length = chunks.length;
} else {
length += chunk.length;
}
});
stream.getBufferedValue = () => {
if (array) {
return chunks;
}
return isBuffer ? Buffer.concat(chunks, length) : chunks.join('');
};
stream.getBufferedLength = () => length;
return stream;
};
;