Pyret: A new programming language from the creators of Racket

Post by marincounty » Sun, Nov 10, 2013, 2:07 AM UTC

f7t7ft7 wrote: post #131

geofft wrote: post #127

Earlier quoted context omitted.

Quite a few, actually, which is why the Scheme class ended up being awful in practice -- you'd get a bimodal distribution of students where some are already familiar with multiple languages (usually more mainstream than Lisp) and some aren't familiar with any, and the class, by necessity, targeted the trough right between those. So it was too fast for the students who never programmed before, and either too slow or t…

I've seen an MIT Scheme class video, and it was painfully slow and the guy seemed to explain everything in painstaking detail. I've heard about the bimodal distribution, which I believe I witnessed among fellow students when I was taking classes. But I'm having trouble seeing how Scheme made it any worse or how the class was too fast. And, Pyret looks like a terrible beginner language! I like PltScheme, but I can't s…

Post by chongli » Sun, Nov 10, 2013, 2:17 AM UTC

skrishnamurthi wrote: post #163

klrr wrote: post #29

Earlier quoted context omitted.

Lisp syntax is ( ) with a few special forms (def, if, cond etc.). This is really easy to understand and allows the user to go straight forward and learn about the semantics and general programming practice immediately.

That same regularity also means there are few guideposts as a student programs, and this makes it much harder to recover from mistakes. We've looked at a lot data on this (and have taught Racket at every level for decades).

Post by b6fan » Sun, Nov 10, 2013, 2:39 AM UTC

  - method_as_fun = o.my-method
  - method_as_fun(5) # not reached
  + method_as_fun = o.method(:my_method)
  + method_as_fun.call(5) # or method_as_fun[5]

  def f(x)
    g = ->y {x + y}
    g[2]
  end
  f(2)

  def f(x)
    @x = x
    def g(y); @x + y; end
    g(2)
  end
  f(2)

Post by garysweaver » Sun, Nov 10, 2013, 2:41 AM UTC

skrishnamurthi wrote: post #179

garysweaver wrote: post #38

> Most “scripting” languages don't support annotations for checking parameters and return values I coded in Java for many years and Ruby for the last several, the lack of explicit type checking in method signatures or via annotations built into Ruby has not gotten in the way enough where I felt I needed to add something to decorate methods to do some generic form of type checking in Ruby. When I really need to check…

As you wish! We now have two Ruby examples on the home page. You may not call it love. <-:

Post by vidarh » Sun, Nov 10, 2013, 3:32 AM UTC

carterschonwald wrote: post #186

gizmo wrote: post #7

Pyret looks like a there's a lot going on, based on the examples. It has implicit returns, special purpose syntax for data structures, iterators, assertions, refinements, etc. Having support for more stuff makes it less suitable as a teaching language, not more. Pyret looks like a has the good bits of Python plus a whole bunch of other cool stuff. But the language is pretty complex as a result. Cool? Yup! Good for te…

The grammar can be described with a single page in actual BNF. Thats AMAZING. The only languages have shorter grammars are core lisp/scheme. Ruby is fundamentally impossible to describe with a BNF.