Why MIT switched from Scheme to Python

Post by danbmil99 » Thu, Mar 26, 2009, 9:20 AM UTC

stcredzero wrote: post #14

trjordan wrote: post #3

I think there's something else here, implicit in Sussman's comment, that's important. MIT was founded on a philosophy of practicality, and everything else is secondary. If you couple that with the belief that fundamental computer science is the most efficient way to enhance practical software engineering, Scheme was a wonderful choice. Java and C++ may have been more directly practical to software engineers, but they…

My concern is that "practicality" is often just a code word for "resembles Java or whatever else I was comfortable with so I can continue on doing what I've always done before." (With the result that the student learns less than if they were required to do something truly different.) Reminds me of this post that came up on HN not too long ago: http://funcall.blogspot.com/2009/03/not-lisp-again.html

    (define (deriv f)
       (define (f-prime x)
         (/ (- (f (+ x dx)) (f x))
            dx))
       f-prime)

Post by danbmil99 » Thu, Mar 26, 2009, 9:40 AM UTC

10ren wrote: post #71

tlb wrote: post #33

Earlier quoted context omitted.

People often say that Java has great libraries, but is it true? AWT is crufty and ugly. Maybe there are impressive XML parsers (Xerxes is 188,000 lines of Java!), but I don't want those. Numerical libraries seem bad. So what is the library that might convince me to use Java for something?

http://freshmeat.net/tags/java-libraries I'm not saying they are all are high quality, or relevant to your task, or that there are no C++ or Python equivalents - just that there is a high quantity of Java projects. Why not have a quick search? Maybe there is a project there that will convince you. AWT is about the most prejudiced example imaginable - it was rushed out, disowned by its authors, and quickly replaced. I…

Post by sharkbrainguy » Thu, Mar 26, 2009, 10:03 AM UTC

danbmil99 wrote: post #111

stcredzero wrote: post #14

Earlier quoted context omitted.

My concern is that "practicality" is often just a code word for "resembles Java or whatever else I was comfortable with so I can continue on doing what I've always done before." (With the result that the student learns less than if they were required to do something truly different.) Reminds me of this post that came up on HN not too long ago: http://funcall.blogspot.com/2009/03/not-lisp-again.html

(define (deriv f) (define (f-prime x) (/ (- (f (+ x dx)) (f x)) dx)) f-prime) jeez, I wish it was easy to do that in Python. Python's main limitation, IMSHO, is lack of homoiconicity. Yes, I said it!

  dx = 0.00001

  def deriv(f):
      return lambda x: \
             (f(x + dx) - f(x))/dx


  In [11]: def cube(x):
     ....:     return x*x*x
     ....: 

  In [12]: deriv(cube)(5)
  Out[12]: 75.000149996640175

Post by sharkbrainguy » Thu, Mar 26, 2009, 10:33 AM UTC

mahmud wrote: post #103

NonEUCitizen wrote: post #55

Earlier quoted context omitted.

lucene

Which is a clone of a Common Lisp search engine ;-)

Post by scott_s » Thu, Mar 26, 2009, 2:06 PM UTC

abecedarius wrote: post #109

scott_s wrote: post #102

Earlier quoted context omitted.

In my current project, I've implemented a source-to-source compiler. In the places where I emit C code, I usually don't have a handle to the scopes above me. I could get one, but it would take more work. The code I generate has no indents and no newlines. Not having to keep track of these makes life simpler. To make my generated code more legible, I just run indent on it.

I've written C code emitters too. FWIW, I've found nicely-indented output templates help to keep the source code of the emitter clear (and with no need to get at the enclosing scopes). But the question you raised was whether indentation-only was harder to generate, and I'd say no, because code.replace('\n', '\n ') is as simple as '{' + code + '}', if slightly slower.