PyPy.js: Now faster than CPython

Post by hajile » Wed, May 07, 2014, 5:46 PM UTC

inportb wrote: post #64

hajile wrote: post #61

Earlier quoted context omitted.

I suggest you read SICP and gain an appreciation for higher-order functions. Once you do, you will probably have answered your own question. http://mitpress.mit.edu/sicp/

Why would zo1 want to read SICP? zo1 is clearly quite happy with Python's named functions, and has no immediate incentive to "read SICP and gain an appreciation for higher-order functions."

Post by zo1 » Wed, May 07, 2014, 6:03 PM UTC

darkarmani wrote: post #69

hajile wrote: post #61

Earlier quoted context omitted.

I suggest you read SICP and gain an appreciation for higher-order functions. Once you do, you will probably have answered your own question. http://mitpress.mit.edu/sicp/

Doesn't that section use lambda for anonymous functions? http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-12.html... The OP is complaining about lambda functions in Python.

Post by vanderZwan » Wed, May 07, 2014, 7:15 PM UTC

rfk wrote: post #65

vanderZwan wrote: post #16

I am colourblind and have problems with your choice of red and green for graphs.

I had not considered this, it's currently just using whatever default colours matplotlib selected. Thanks for the heads-up!

Post by hajile » Wed, May 07, 2014, 7:22 PM UTC

zo1 wrote: post #72

hajile wrote: post #71

Earlier quoted context omitted.

I either assume that the parent poster was serious about the question or rhetorical. Given the apparent lack of knowledge, I assume the question was serious. If the question was serious, does it not deserve a serious response? Faced with squeezing an explanation into a limited post or recommending one of the best books on computer science (written by teachers with many years experience in teaching these self-same pri…

Indeed, you are right. I was quite curious about them, and I wanted to know if there was something I was missing. Some reasoning that I knew not of, and that others did. However, I'm about halfway through the chapter on "Higher order procedures" in the book you linked to, and have skimmed the rest of that chapter. And I've yet to find a valid pro for anonymous methods. Nothing I've found so far as to the benefit of u…

  def add4Mul2(x):
    z = 4
    y = 2
    return (x + y) * z

  lst = [1,2,3,4]
  x = map(add4Mul2, lst)

  x = map(lambda x: (x+2)*4, [1,2,3,4])

Post by hajile » Wed, May 07, 2014, 8:02 PM UTC

zo1 wrote: post #78

hajile wrote: post #74

Earlier quoted context omitted.

In python, it would be proper to say that ALL functions are lambdas except that some/most of those lambdas are assigned to variables via syntactic sugar (this is made very plain in sicp which is the main reason for suggesting it).The only thing different about python vs most other languages is guido refusing to implement multi-line lambdas. As to any complaint, lambdas exist in python (that is, are made accessible to…

"In python, it would be proper to say that ALL functions are lambdas except that some/most of those lambdas are assigned to variables via syntactic sugar" If a function is "assigned to a variable" then it's no longer a lambda, because it's bound to an identifier. But I suppose the lines are a tad blurred.

  x = lambda x: x+x #a lambda, but has a named pointer
  x = 5

  def x(y):
    return y+y
  
  x = 5 #the "named" function above is now without a pointer

  //lambda expression
  var x = function (){};

  //named function
  function x() {}

  //named lambda expression
  var x = function x() {};

  //self-executing lambda (returns 5)
  (function (x) {return x;}(5));

  (lambda x: x)(5)

  my_module = (function (self) {
    "use strict"
    self = self || {};

    //private
    //pretty much inaccessible to the outside scope
    var privateVar = 5;
    //lambda expression again
    var privateFunc = function () {};

    //public
    self.publicVar = 5;
    self.publicFunc = function () {};
    self.getPrivateVar = function () {
      return privateVar;
    };

    return self;
  }(my_module));

  my_module.publicVar = 8;
  my_module.publicFunc();
  my_module.getPrivateVar();

  func1(function () {
    func2(function () {
      func3(function () {
        func4(function () {
      })
    })
  })