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Pyret: A new programming language from the creators of Racket

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Re: Pyret: A new programming language from the creators of Racket

#61

Post by stiff »

jashkenas wrote: post #57
stiff wrote: post #35

Earlier quoted context omitted.

I don't think the story of literate programming can be of any help predicting how well this idea here can work out. Literate programming is not "embedding documentation". The main idea was to separate the order in which the code is read from the order in which the compiler sees it, and it embeds the code in the documentation, not vice versa. It was a very idiosyncratic thing, hard to imagine a team of programmers in…

That's not the "main idea". Originally, it was a part of the suggested way to accomplish the goal ... but the main idea is this: > Let us change our traditional attitude to the construction of programs: > Instead of imagining that our main task is to instruct a computer what > to do, let us concentrate rather on explaining to human beings what we > want a computer to do. > — Knuth If your program can be read more as…

It's like saying the main idea in C was to allow writing programs. At this level of generality it is indistinguishable from tens of projects with similar goals, including also earlier ones.

Re: Pyret: A new programming language from the creators of Racket

#62

Post by fgoodman »

xfs wrote: post #18
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…

Actually Brown teaches Intro to Programming Languages using Pyret. http://cs.brown.edu/courses/cs173/2013/software.html

They also teach the Accelerated Intro to Computer Science (the first cs course some students take) using Pyret. http://cs.brown.edu/courses/cs019/2013/

Re: Pyret: A new programming language from the creators of Racket

#63

Post by mageofmath »

rhizome31 wrote: post #50
tel wrote: post #2

Python-like syntax with pattern matching and recursive ADTs!? What a great idea!

+1 This looks a lot like the language I've been dreaming about. I actually like the explicit `end` keyword to materialize the end of blocks. The lambda expression syntax, as illustrated by the filter/map/fold example, looks like Ruby blocks with a much simpler syntax. A couple of questions to the crew: Why advertise it as a teaching language ? As a working programmer this looks very appealing to me. Are there limitat…

It still has some performance issues that I say would make it hard to put into an industry environment.

I think the teaching language part is in reference to Captain Teach, an IDE++ that the developers are using in the classes to support code review, automatic backups, and more.

Pyret is being designed with the goal of encouraging good code, with tests being an integral part of every function, and clear differentiation between mutation and simple let bindings. I would teach this language just for those features, so my students would see how easy it is to get lost in spooky action at a distance, or in debugging the wrong portion of your code.

Re: Pyret: A new programming language from the creators of Racket

#64

Post by qiemem »

GhotiFish wrote: post #15
terhechte wrote: post #3

"""Pyret makes testing a natural part of the programming process. Functions can end in a where: clause that holds unit tests for the function. These assertions are checked dynamically.""" Fantastic idea! I'll keep that in mind, should be fairly easy to extend Lisps or other AST-Macro enabled languages (Elixir, Julia, Python) with such a functionality. I really like that. It makes it easy to work on a function and cod…

That really caught my eye! Does anyone have any experience with workflows like this? Are tests next to code a pragmatic technique?

Python has them in the form of doctests. They are generally frowned upon as they tend to significantly clutter up code and documentation when they actually provide comprehensive testing. That said, Pyret's format may escape that fate as they are given their own section which most modern editors should be capable of folding.

Doctests: http://docs.python.org/2/library/doctest.html

Re: Pyret: A new programming language from the creators of Racket

#65

Post by mageofmath »

andybak wrote: post #12
klrr wrote: post #10

This project seems really promising, but I got one concern. Lisp's syntax have been one of its strength for beginners. Easy to learn, easy to solve common errors. I don't see the point of having Python-like syntax really, the user could learn other syntax after they've understood programming .

My jaw dropped slightly to see someone suggest Lisp syntax would be a better starting place for beginners than Python's syntax. Is it just me or is that a fairly unorthodox point of view?

At Brown (the place this research is coming from) one of the main CS intro courses is taught in Racket. It's worked really well and people enjoy the simplicity in getting programs running quickly. People with previous programming experience have more trouble than true beginners at that point in the course.

The course later moves into 3 other languages (OCaml, Scala, and Java) to try and get the beginners not focused on any particular language, though there is some debate on whether that effectively teaches the beginners any language particularly well.

Pyret would definitely be a candidate for replacing OCaml in that sequence as anything with better error messages would be very welcome.

Re: Pyret: A new programming language from the creators of Racket

#67

Post by pjmlp »

ash wrote: post #28
6ren wrote: post #16

Earlier quoted context omitted.

It clutters the code. Tests are a form of documentation, but too much in the code, like too many comments, obscures. Higher level unit tests (acceptance tests) can be quite long, especially if there's a lot of setup - unlike their example code. Literate programming tried embedded documentation, but didn't catch on (even with Knuth's backing). Embedding tests makes them easier to keep in sync, but tests are already ke…

> Literate programming… didn't catch on I would argue literate programming is experiencing a renaissance, thanks to docco: https://github.com/jashkenas/docco

Not really, I never heard of docco and am yet to see a RFP for a node.js project from my employer's enterprise customers.

Re: Pyret: A new programming language from the creators of Racket

#68

Post by ricw »

rhizome31 wrote: post #50
tel wrote: post #2

Python-like syntax with pattern matching and recursive ADTs!? What a great idea!

+1 This looks a lot like the language I've been dreaming about. I actually like the explicit `end` keyword to materialize the end of blocks. The lambda expression syntax, as illustrated by the filter/map/fold example, looks like Ruby blocks with a much simpler syntax. A couple of questions to the crew: Why advertise it as a teaching language ? As a working programmer this looks very appealing to me. Are there limitat…

I'd disagree with the "end" keyword. You could add more whitespace, which our brains naturally deal with very well, or you add more "cruft" which we have to actively think about. In typography white space is what makes good layout work. And here we're going back to replacing white space with a word. So from those perspectives I think the "end" keyword is a regression.

Having said that, it's the first language that I prefer from a typographical perspective to python. So very well done on everything else.

Re: Pyret: A new programming language from the creators of Racket

#69

Post by msutherl »

6ren wrote: post #16
terhechte wrote: post #3

"""Pyret makes testing a natural part of the programming process. Functions can end in a where: clause that holds unit tests for the function. These assertions are checked dynamically.""" Fantastic idea! I'll keep that in mind, should be fairly easy to extend Lisps or other AST-Macro enabled languages (Elixir, Julia, Python) with such a functionality. I really like that. It makes it easy to work on a function and cod…

It clutters the code. Tests are a form of documentation, but too much in the code, like too many comments, obscures. Higher level unit tests (acceptance tests) can be quite long, especially if there's a lot of setup - unlike their example code. Literate programming tried embedded documentation, but didn't catch on (even with Knuth's backing). Embedding tests makes them easier to keep in sync, but tests are already ke…

You would think we'd have editors by now that could, say, hide all the tests to declutter the code while you're reading it.

Re: Pyret: A new programming language from the creators of Racket

#70

Post by dbpatterson »

sirclueless wrote: post #58
clarkevans wrote: post #8

Earlier quoted context omitted.

I think the colon isn't a mistake, it clearly delineates an indented block; I think it's a great marker that indented languages might want to standardize on. Perhaps syntax issue is that it has both a colon and an "end" marker? The former indicates indentation-based syntax, the latter is often used in white-space agnostic contexts. The result of using both is confusion.

Pyret doesn't actually have an indentation-based format (so far as I know) it just happens to look like python.

That's correct. There is a preferred indentation (enforced by the emacs mode and our online editor built on CodeMirror), but whitespace is only needed to separate things - the actual amount of whitespace never matters.

So, for example, you can move chunks of code from one place to another and select it all and re-indent - something that you can't do (in general) in Python. It also makes it easier to programatically generate code.

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