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    generate-function

    2.3.1¬†‚Äʬ†Public¬†‚Äʬ†Published

    generate-function

    Module that helps you write generated functions in Node

    npm install generate-function
    

    build status

    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

    const genfun = require('generate-function')
    const { d } = genfun.formats
     
    function addNumber (val) {
      const gen = genfun()
     
      gen(`
        function add (n) {')
          return n + ${d(val)}) // supports format strings to insert values
        }
      `)
     
      return gen.toFunction() // will compile the function
    }
     
    const 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)

    function multiply (a, b) {
      return a * b
    }
     
    function addAndMultiplyNumber (val) {
      const gen = genfun()
      
      gen(`
        function (n) {
          if (typeof n !== 'number') {
            throw new Error('argument should be a number')
          }
          const result = multiply(${d(val)}, n + ${d(val)})
          return result
        }
      `)
     
      // use gen.toString() if you want to see the generated source
     
      return gen.toFunction({multiply})
    }
     
    const addAndMultiply2 = addAndMultiplyNumber(2)
     
    console.log(addAndMultiply2.toString())
    console.log('(3 + 2) * 2 =', addAndMultiply2(3))

    You can call gen(src) as many times as you want to append more source code to the function.

    Variables

    If you need a unique safe identifier for the scope of the generated function call str = gen.sym('friendlyName'). These are safe to use for variable names etc.

    Object properties

    If you need to access an object property use the str = gen.property('objectName', 'propertyName').

    This returns 'objectName.propertyName' if propertyName is safe to use as a variable. Otherwise it returns objectName[propertyNameAsString].

    If you only pass gen.property('propertyName') it will only return the propertyName part safely

    License

    MIT

    Install

    npm i generate-function

    DownloadsWeekly Downloads

    1,849,677

    Version

    2.3.1

    License

    MIT

    Unpacked Size

    9.04 kB

    Total Files

    7

    Last publish

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