trevnorris/reblaze

Rewrite your JS on the fly using JS

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A crazy way of template-izing your JS Functions and Generators so they can be generated on the fly.

This should be used for methods that are instantiated once then used many times, since currently the function generation does take quite a bit of time to do.

API

reblaze(values[, name], fn)

• values {Object}
• name {String} Default ''
• fn {Function}
• Returns new Function

Examples

Let's show a simple example then allow you to go experiment.

'use strict';

const reblaze = require('reblaze');

function Matrix(rows, cols) {
  this._rows = rows >>> 0;
  this._cols = cols >>> 0;
  // Replace template entries with fields in passed object.
  this.sumCols = reblaze({ COLS: this._cols, ROWS: this._rows }, sumCols);

  this._data = new Uint32Array(this._rows * this._cols);
}

// This will look funky due to the template convention.
function sumCols() {
  const data = this._data;
  // Sum of values may exceed a uint32
  const sum = new Float64Array(((COLS)));
  for (var i = 0; i < ((COLS)) * ((ROWS)); i++) {
    sum[i % ((COLS))] += data[i];
  }
  return sum;
}

// Build a new Matrix instance with custom sumCols().
const m = new Matrix(11, 7);

Now sumCols on the instance m:

function sumCols() {
  const data = this._data;
  const sum = new Float64Array(7);
  for (var i = 0; i < 7 * 11; i++) {
    sum[i % 7] += this[i];
  }
  return sum;
}

It will also automatically take care of object properties as well. For example:

function runMe(foo) {
  return foo[((BAR))];
}

const fn = reblaze({ BAR: 'bar' }, runMe);

And the output for the new fn instance:

function runMe(foo) {
  return foo.bar;
}

The name of the function can also be replaced by passing a second optional argument.

function replaceMe(foo) {
  return foo[((BAR))];
}

const fn = reblaze({ BAR: 'bar' }, 'wereReplaced', replaceMe);

Will generate the following function:

function wereReplaced(foo) {
  return foo.bar;
}

If you want to have the full require, __filename, etc. in your function pass module as an optional third (or second if name isn't provided) argument.

function foop() {
  require(__dirname + '/' + ((NAME)));
}
reblaze({ NAME: 'mod_name' }, module, foop);

So, give it a whirl and report any bugs. In the future I plan on implementing even more meta-ness where reblaze can run on itself and return optimized instances for a given construction case.