Attribution Based Economics (ABE) is a new paradigm for economics that revises several foundational assumptions governing today’s systems, including the nature of economic value and the origin of money. In this new paradigm, open source software becomes economically viable and, indeed, even financially favored over proprietary models. This talk describes our experiences implementing an early prototype for the Qi project, and also how Racket will be an essential part of the solution as ABE scales past the pilot stage.
The Scheme language's small size isn't necessarily a strength
So I was reading through part of the EmacsWiki and in the article on the Scheme programming language there are references to this ancient online debate from August of the year 2000 at the comp.lang.lisp Usenet group started by the late Erik Naggum, who was apparently a somewhat opinionated and inflammatory individual, who brought up the Scheme/Common Lisp debate on comment thread about someone being confused about how the CASE clause works.
The Scheme language standard at the time was R5RS, Naggum's argument is a common refrain from Scheme fans such as myself, and he was arguing with Kent Pitman ( @kentpitman ) who was one of the sub-committee chairs of the Common Lisp X3J13 standardization process, and is the editor and maintainer of the Common Lisp HyperSpec, an online form of the Common Lisp specification. Kent Pittman's reply I thought was very well-reasoned, and worth re-posting here (quote):
I just absolutely don't believe the Scheme standard is fairly cited as a model of a "better" standard. It is enormously vague on numerous matters of consequence. It omits really essential functionality that would be needed to write any seriously portable programs. It was stagnant for years on quibbles over some of the silliest syntax details. In my opinion, it's a toy language. There are real commercial Scheme implementations, but only by the sheer will of those implementers who've gone beyond the so-called standard and written in the things that the standard ought to have said in order to make the language finally useful. It achieves its "prettiness" and its "smallness" on the back of just plain leaving stuff out where it would appear to "clutter", and whatever you think of CL, I personally reject any claim that the Scheme is a model of improvement.
(end quote)
I wouldn't go so far as to call Scheme a "toy language" because the parts of the standard that are well-defined are solid and very useful. But yes, it seems the only useful implementations do solve these problems not addressed by the standard in completely different ways that makes it very difficult to write a Scheme program on one implementation that runs on another. Try to write one program that runs on MIT Scheme, Guile, Chez, Racket, Bigloo, Cyclone, Stklos, and Gambit. Try to even compute what set of SRFI (language extensions) are common to all of them. Most Scheme programmers have to pick just one implementation and stick to it without much hope of ever porting their programs to other implementations. It is possible to do it, easier than porting a program from Python to C++, but still not at all as easy as running the same Common Lisp program on SBCL, ECL, ABCL, or Franz.
So I do agree with @kentpitman that there are some pretty important details left up to the implementers simply because none of them could agree on what to do and punted the issue rather than resolve it. Later (after the aforementioned Usenet debate) R6RS would try to solve these issues, but that standard was mostly rejected by the larger part of the Scheme community due to a lack of consensus. Much of that work lives on in the SRFIs, while Chez Scheme (R. Kent Dybvig) seems to be sticking to R6RS and is one of the most well-respected Scheme implementations, and a kind of flagship of that standard.
I still have hope for R7RS-large though, which might end up being even larger than X3J13 when all is said and done. Unfortunately, recently John Cowan, chair of the R7RS-large standardization committee threw his hands up in resignation a few months ago after almost 10 years of trying to hammer-out consensus over details of the new R7RS-large standard. Daphne Preston Kendal ( @dpk ) has taken over and is fully capable of continuing the work.
It might be interesting if some Schemers could get together and write a new fully R7RS-compliant Scheme-to-Scheme compiler in R7RS-small Scheme, with all of the COND-EXPAND expressions in place to run on all of the major R7RS-compatible Scheme implementations. This compiler would simply translate its input into code that the host Scheme compiler can compile, deferring low-level implementation details to the host. The compiler should be one massive file that you could just load into any Scheme compiler and it just works. Then this compiler maybe, just maybe could become The Scheme Standard. A good starting point would be the work of Marc Nieper-Wißkirchen who has written Rapid Scheme which compiles R7RS Scheme to another host Scheme, but it only supports Chibi and Larceny as the hosts.
Da qualche tempo mi sto interessando alla famiglia di linguaggi LISP/SCHEME. Cercando informazioni in rete ho trovato quest’articolo che mi è sembrato molto interessante e così, con il permesso dell’autore Micah Cantor, ho pensato di pubblicare la mia traduzione.
L’ articolo originale, “Why learn Racket? A student’s perspective” potete leggerlo sul suo blog.
Sawzall, inspired heavily by dplyr and the relational algebra. Sawzall builds on top of Alex Harsanyi’s data-frame package, but provides a set of operations that are designed to compose and avoid mutating the original data-set, leading to a natural style of data manipulation following the idea of "do this, then that".
The --installation flag (shorthand for --scope installation) installs packages for all users of a Racket installation and ensures resyntax is in your $PATH.
λ Racket version 8.9 is now available from
— @racketlang
「 Some languages convey ideas more easily than others. And some programming languages convey solutions better than others. Therefore Racket is a language for making languages, so that a programmer can write every module in a well-suited language 」