# generate-function
  
  Module that helps you write generated functions in Node
  
  ```
  npm install generate-function
  ```
  
  [![build status](http://img.shields.io/travis/mafintosh/generate-function.svg?style=flat)](http://travis-ci.org/mafintosh/generate-function)
  
  ## Disclamer
  
  Writing code that generates code is hard.
  You should only use this if you really, really, really need this for performance reasons (like schema validators / parsers etc).
  
  ## Usage
  
  ``` js
  var genfun = require('generate-function')
  
  var addNumber = function(val) {
    var fn = genfun()
      ('function add(n) {')
        ('return n + %d', val) // supports format strings to insert values
      ('}')
  
    return fn.toFunction() // will compile the function
  }
  
  var add2 = addNumber(2)
  
  console.log('1+2=', add2(1))
  console.log(add2.toString()) // prints the generated function
  ```
  
  If you need to close over variables in your generated function pass them to `toFunction(scope)`
  
  ``` js
  var multiply = function(a, b) {
    return a * b
  }
  
  var addAndMultiplyNumber = function(val) {
    var fn = genfun()
      ('function(n) {')
        ('if (typeof n !== "number") {') // ending a line with { will indent the source
          ('throw new Error("argument should be a number")')
        ('}')
        ('var result = multiply(%d, n+%d)', val, val)
        ('return result')
      ('}')
  
    // use fn.toString() if you want to see the generated source
  
    return fn.toFunction({
      multiply: multiply
    })
  }
  
  var addAndMultiply2 = addAndMultiplyNumber(2)
  
  console.log('(3 + 2) * 2 =', addAndMultiply2(3))
  ```
  
  ## Related
  
  See [generate-object-property](https://github.com/mafintosh/generate-object-property) if you need to safely generate code that
  can be used to reference an object property
  
  ## License
  
  MIT