7 ms·

Next version of Shen will be BSD licensed

119 points by tizoc 12y ago

reubensutton 12y ago
I had a read of the website, but I don't really understand what people use Shen for, but presumably, it has some benefits over other lisps? Can anyone enlighten me?
- saosebastiao 12y ago
  It wasn't really used for anything before, because of the bizarre custom license. However, it looks like it has a lot of interesting features that people might want to use. For example, it can be trivially embedded in pretty much any other language by implementing a handful of core functions. It has an embedded prolog DSL. It has pattern matching, static type checking, lazy evaluation.
  - Igglyboo 12y ago
    I just read over the license, didn't see too weird except the part about the spec. If I read it correctly you can't modify shen if your modifications don't conform to the specification.
    - hga 12y ago
      The problem is the license tries to say the same thing at least 3 times, and that results in tremendous ambiguity. If you wanted to use it commercially and safely, you'd have to spend quite a bit on an IP lawyer with no guarantee he'd give you an OK. In a universe with so many good languages, many with much bigger communities (in part because of the license), with well understood and often tested in court licences, it's a non-starter. The intent is fine, everybody's code will run on your port, modulo bugs, and is plainly stated in the last line of the licence: “Thou shalt not break the spec” It's the execution by someone who's a computer scientist, not a lawyer, nor very familiar with IP law.
- hga 12y ago
  From the fine website http://www.shenlanguage.org/ http://www.shenlanguage.org/ Shen is a portable functional programming language that offers pattern matching, lambda calculus consistency, macros, optional lazy evaluation, static type checking, an integrated fully functional Prolog, and an inbuilt compiler-compiler. Among other things, it's an attempt to create a Lisp that incorporates some of the things you find in functional languages like Haskell. Here's an essay, from an invited talk for the 2009 European Conference on Lisp, on the motivations to create Qi and then Shen: http://www.lambdassociates.org/blog/nextlisp(1).htm http://www.lambdassociates.org/blog/nextlisp(1).htm
  - e12e 12y ago
    Very interesting essay. Kind of reminds me of OMeta and some of the stuff that comes out of VPRI with Alan Kay et al. But mostly the approach reminds me of OMeta's way of "absorbing the easy stuff" and "infiltrating" - but from a different (and perhaps more rigorous) angle. Now if only the (cheap!) book on Shen was available as a DRM-free epub book.
    - hga 12y ago
      Indeed, and that's one of the things I find attractive about it, especially since I believe Lisp is the One True Way and much of the parsing effort that VPRI worked on is irrelevant to me (but not things like the idea of parsing illustrations in RFCs and generating a TCP/IP stack!). As for the book, right now the work on the project by the author is supported by direct patronage or buying his books. And there's much more in the book than just "leaning Shen". Here's the web page for it: http://www.shenlanguage.org/learn-shen/TBoS/ http://www.shenlanguage.org/learn-shen/TBoS/ Which includes the preface, table of contents, and conceptual dependency table, i.e. what previous chapters you need to have mastered to understand each chapter. From the chapter titles and subtitles, here's stuff that goes substantially beyond "learning Shen": Higher Order Functions (e.g. partial application and currying) Non-determinism (non-deterministic algorithms) Shen-YACC (sigh, needed for e.g. pattern matching) Lambda Calculus Writing Good Programs Sequent Calculus The SECD Machine Shen Prolog (12 pages on Prolog per se) The Compilation of the Sequent Calculus And there's a lot of material on types (one of the features of Qi/Shen). So you get a whole lot of CS exposition in the context of Shen.
- mahmud 12y ago
  Shen is Lisp-NG. It's the infusion of Lisp with 30 years of _proper_ PLT research. It's a Lisp that learned from its successors; and for that, it's a Big Deal™.
  - lispm 12y ago
    30 years without practical applications is quite an achievement.
    - hga 12y ago
      There have been plenty of practical applications for this stuff, just not directly in Lisp. Haskell and the ML family have interesting stories to tell; learning ML is on my list simply so that I can understand a lot of this research. Yes, Lisp is the One True Way, but that doesn't mean it's the source of all good ideas in CS.
      - lispm 12y ago
        I'm talking about this specific Lisp dialect (from Sequent Calculus Research over Qi to Shen). It has near zero applications in 30 years. I would not know why I would write anything I have written in the past in Scheme or Lisp, in this language and would it give me as advantage. The basic application seems to be programming language research and education. True, many programming languages have applications, but for this I don't know any... Common Lisp has a lot of applications in possible areas, for example that are a dozen theorem provers from PVS (used by NASA for example) to ACL2 written in Lisp. I'm not aware of a system remotely similar in Shen (or Qi) that's used by people.
        hga 12y ago
        Two arguments here are that: 1. Qi/Shen are very young, less than 10 years old. 2. Their adoption has been crippled by wonky licenses. That said, the sequent calculus can be viewed as an implementation detail, I don't believe it's integral to the use of Shen. There are arguments for adding features from non-Lisp functional languages, which I'll note in the forms of OCaml, F# and Haskell are seeing real world use. I'll come back to this question after learning Shen (the wonky license has kept me from more than dipping my toe into it).
chriswarbo 12y ago
This is welcome news. Qi (the predecessor of Shen) gets mentioned every now and then in programming language discussions (eg. it has a Turing Complete type system), but I've refused to try it so far due to its non-Free license.
- deleted 12y ago
  [deleted]
VLM 12y ago
I'd like to buy the book related to the language, looks interesting, I am willing to pay list price, but fedex wants a mere $64 to ship it. Meanwhile I'm an electronics experimenter kind of guy and I currently have some weird semiconductors arriving from China where the entire order including shipping was only about $45 (I believe the shipping portion was $8). Admittedly a very small and light packet compared to a textbook, but still... In an online, ebook, internet world, something is wrong with $64 shipping charge from the UK yet only $8 from China. Maybe a helpful soul could have a pallet of books shipped to China, then send them around the world for the usual Chinese shipping "pocket change" cost.
- slackstation 12y ago
  Why in 2015 are we flying paper half-way around the world? Doesn't Amazon (and others) have a print-on-demand service that would be more cost effective and not waste the fuel of flying 20lbs of paper across an ocean?
  - steveklabnik 12y ago
    As someone who reads physical books almost exclusively, print on demand is getting better, but offset still reigns supreme.
    - hga 12y ago
      I really like books, although I'm comfortable with online/ebook reading, and I have to say that the company chosen for this book delivers superb quality compared to every US origin print on demand book I've looked at, at least for the first edition of this book. I can't tell it from offset (although some embedded links came our grey because I assume they were delivered in color and not caught in galleys). Even the color artwork looks great---ironically, it's the back corner where the company puts its standard ISBN/price/self-advertising rectangle that looks bad when looked at very closely and makes clear someone dropped the ball somewhere (maybe that's an artifact of the author choosing such a high quality for the cover).
  - Sanddancer 12y ago
pnathan 12y ago
This is really really good news. Shen has some really cool aspects, but the licensing is, to put it mildly, weird. Having a standard license will really help adoption and investigation.
lkrubner 12y ago
If you are interested in Shen, you might be interested in previous discussions on Hacker News: https://news.ycombinator.com/item?id=8250316 https://news.ycombinator.com/item?id=8250316 https://news.ycombinator.com/item?id=8359796 https://news.ycombinator.com/item?id=8359796 https://news.ycombinator.com/item?id=3117235 https://news.ycombinator.com/item?id=3117235 Also, check out Fogus's summary of Lisps: http://blog.fogus.me/2011/05/03/the-german-school-of-lisp-2/ http://blog.fogus.me/2011/05/03/the-german-school-of-lisp-2/ I signed up as a donor who gives 5 pounds a month to this project, because the ideas going into this project are extremely innovative and deserve support.
nutate 12y ago
46 functions in Kλ... this is exactly what people like me need in a programming language. I have a hard enough time remembering if it's add() append() push() to throw something onto an array in Python or Javascript. Knowing that clojure has a cool syntax or cool function-to-do-something isn't all that awesome when I need to just code something. If I was all in on a language and not a jack of all trades, I'd love those special features. As is, I like a simple list of reserved words that I have a half chance of remembering. Glad to see this funding concept worked for the community.
- mijoharas 12y ago
  I often have the same problems as you (and I have to say, I constantly forget whether it's push/append too, even in my most used languages). My solution to it has been to setup my development environment to provide the requisite autocompletion and linting (I use emacs with the brilliant spacemacs package to be able to have "the one ide for all languages"). It takes a bit of setting up for each language you use, but if you do that as primary setup on an as-and-when basis it's not that bad (and "starter-packs" that have packages that work together are great)
- mijoharas 12y ago
  I often have the same problems as you (and I have to say, I constantly forget whether it's push/append too, even in my most used languages). My solution to it has been to setup my development environment to provide the requisite autocompletion and linting (I use emacs with the brilliant spacemacs package to be able to have "the one ide for all languages"). It takes a bit of setting up for each language you use, but if you do that as primary setup on an as-and-when basis it's not that bad (and "starter-packs" that have packages that work together are great)
- mijoharas 12y ago
  I often have the same problems as you (and I have to say, I constantly forget whether it's push/append too, even in my most used languages). My solution to it has been to setup my development environment to provide the requisite autocompletion and linting (I use emacs with the brilliant spacemacs package to be able to have "the one ide for all languages"). It takes a bit of setting up for each language you use, but if you do that as primary setup on an as-and-when basis it's not that bad (and "starter-packs" that have packages that work together are great)
tluyben2 12y ago
I sponsored this move and I am making a port. I really love the language and hope more people will!
tluyben2 12y ago
I sponsored this move and I am making a port. I really love the language and hope more people will!
tluyben2 12y ago
I sponsored this move and I am making a port. I really love the language and hope more people will!
tluyben2 12y ago
I sponsored this move and I am making a port. I really love the language and hope more people will!
tluyben2 12y ago
I sponsored this move and I am making a port. I really love the language and hope more people will!

119 points by tizoc 12y ago

I had a read of the website, but I don't really understand what people use Shen for, but presumably, it has some benefits over other lisps? Can anyone enlighten me?

saosebastiao 12y ago
It wasn't really used for anything before, because of the bizarre custom license. However, it looks like it has a lot of interesting features that people might want to use. For example, it can be trivially embedded in pretty much any other language by implementing a handful of core functions. It has an embedded prolog DSL. It has pattern matching, static type checking, lazy evaluation.
- Igglyboo 12y ago
  I just read over the license, didn't see too weird except the part about the spec. If I read it correctly you can't modify shen if your modifications don't conform to the specification.
  - hga 12y ago
    The problem is the license tries to say the same thing at least 3 times, and that results in tremendous ambiguity. If you wanted to use it commercially and safely, you'd have to spend quite a bit on an IP lawyer with no guarantee he'd give you an OK. In a universe with so many good languages, many with much bigger communities (in part because of the license), with well understood and often tested in court licences, it's a non-starter. The intent is fine, everybody's code will run on your port, modulo bugs, and is plainly stated in the last line of the licence: “Thou shalt not break the spec” It's the execution by someone who's a computer scientist, not a lawyer, nor very familiar with IP law.
hga 12y ago
From the fine website http://www.shenlanguage.org/ http://www.shenlanguage.org/ Shen is a portable functional programming language that offers pattern matching, lambda calculus consistency, macros, optional lazy evaluation, static type checking, an integrated fully functional Prolog, and an inbuilt compiler-compiler. Among other things, it's an attempt to create a Lisp that incorporates some of the things you find in functional languages like Haskell. Here's an essay, from an invited talk for the 2009 European Conference on Lisp, on the motivations to create Qi and then Shen: http://www.lambdassociates.org/blog/nextlisp(1).htm http://www.lambdassociates.org/blog/nextlisp(1).htm
- e12e 12y ago
  Very interesting essay. Kind of reminds me of OMeta and some of the stuff that comes out of VPRI with Alan Kay et al. But mostly the approach reminds me of OMeta's way of "absorbing the easy stuff" and "infiltrating" - but from a different (and perhaps more rigorous) angle. Now if only the (cheap!) book on Shen was available as a DRM-free epub book.
  - hga 12y ago
    Indeed, and that's one of the things I find attractive about it, especially since I believe Lisp is the One True Way and much of the parsing effort that VPRI worked on is irrelevant to me (but not things like the idea of parsing illustrations in RFCs and generating a TCP/IP stack!). As for the book, right now the work on the project by the author is supported by direct patronage or buying his books. And there's much more in the book than just "leaning Shen". Here's the web page for it: http://www.shenlanguage.org/learn-shen/TBoS/ http://www.shenlanguage.org/learn-shen/TBoS/ Which includes the preface, table of contents, and conceptual dependency table, i.e. what previous chapters you need to have mastered to understand each chapter. From the chapter titles and subtitles, here's stuff that goes substantially beyond "learning Shen": Higher Order Functions (e.g. partial application and currying) Non-determinism (non-deterministic algorithms) Shen-YACC (sigh, needed for e.g. pattern matching) Lambda Calculus Writing Good Programs Sequent Calculus The SECD Machine Shen Prolog (12 pages on Prolog per se) The Compilation of the Sequent Calculus And there's a lot of material on types (one of the features of Qi/Shen). So you get a whole lot of CS exposition in the context of Shen.
mahmud 12y ago
Shen is Lisp-NG. It's the infusion of Lisp with 30 years of _proper_ PLT research. It's a Lisp that learned from its successors; and for that, it's a Big Deal™.
- lispm 12y ago
  30 years without practical applications is quite an achievement.
  - hga 12y ago
    There have been plenty of practical applications for this stuff, just not directly in Lisp. Haskell and the ML family have interesting stories to tell; learning ML is on my list simply so that I can understand a lot of this research. Yes, Lisp is the One True Way, but that doesn't mean it's the source of all good ideas in CS.
    - lispm 12y ago
      I'm talking about this specific Lisp dialect (from Sequent Calculus Research over Qi to Shen). It has near zero applications in 30 years. I would not know why I would write anything I have written in the past in Scheme or Lisp, in this language and would it give me as advantage. The basic application seems to be programming language research and education. True, many programming languages have applications, but for this I don't know any... Common Lisp has a lot of applications in possible areas, for example that are a dozen theorem provers from PVS (used by NASA for example) to ACL2 written in Lisp. I'm not aware of a system remotely similar in Shen (or Qi) that's used by people.
      - hga 12y ago
        Two arguments here are that: 1. Qi/Shen are very young, less than 10 years old. 2. Their adoption has been crippled by wonky licenses. That said, the sequent calculus can be viewed as an implementation detail, I don't believe it's integral to the use of Shen. There are arguments for adding features from non-Lisp functional languages, which I'll note in the forms of OCaml, F# and Haskell are seeing real world use. I'll come back to this question after learning Shen (the wonky license has kept me from more than dipping my toe into it).

chriswarbo 12y ago

This is welcome news. Qi (the predecessor of Shen) gets mentioned every now and then in programming language discussions (eg. it has a Turing Complete type system), but I've refused to try it so far due to its non-Free license.

deleted 12y ago
[deleted]

VLM 12y ago

I'd like to buy the book related to the language, looks interesting, I am willing to pay list price, but fedex wants a mere $64 to ship it. Meanwhile I'm an electronics experimenter kind of guy and I currently have some weird semiconductors arriving from China where the entire order including shipping was only about $45 (I believe the shipping portion was $8). Admittedly a very small and light packet compared to a textbook, but still... In an online, ebook, internet world, something is wrong with $64 shipping charge from the UK yet only $8 from China. Maybe a helpful soul could have a pallet of books shipped to China, then send them around the world for the usual Chinese shipping "pocket change" cost.

slackstation 12y ago
Why in 2015 are we flying paper half-way around the world? Doesn't Amazon (and others) have a print-on-demand service that would be more cost effective and not waste the fuel of flying 20lbs of paper across an ocean?
- steveklabnik 12y ago
  As someone who reads physical books almost exclusively, print on demand is getting better, but offset still reigns supreme.
  - hga 12y ago
    I really like books, although I'm comfortable with online/ebook reading, and I have to say that the company chosen for this book delivers superb quality compared to every US origin print on demand book I've looked at, at least for the first edition of this book. I can't tell it from offset (although some embedded links came our grey because I assume they were delivered in color and not caught in galleys). Even the color artwork looks great---ironically, it's the back corner where the company puts its standard ISBN/price/self-advertising rectangle that looks bad when looked at very closely and makes clear someone dropped the ball somewhere (maybe that's an artifact of the author choosing such a high quality for the cover).
- Sanddancer 12y ago

pnathan 12y ago

This is really really good news. Shen has some really cool aspects, but the licensing is, to put it mildly, weird. Having a standard license will really help adoption and investigation.

lkrubner 12y ago

If you are interested in Shen, you might be interested in previous discussions on Hacker News: https://news.ycombinator.com/item?id=8250316 https://news.ycombinator.com/item?id=8250316 https://news.ycombinator.com/item?id=8359796 https://news.ycombinator.com/item?id=8359796 https://news.ycombinator.com/item?id=3117235 https://news.ycombinator.com/item?id=3117235 Also, check out Fogus's summary of Lisps: http://blog.fogus.me/2011/05/03/the-german-school-of-lisp-2/ http://blog.fogus.me/2011/05/03/the-german-school-of-lisp-2/ I signed up as a donor who gives 5 pounds a month to this project, because the ideas going into this project are extremely innovative and deserve support.

nutate 12y ago

46 functions in Kλ... this is exactly what people like me need in a programming language. I have a hard enough time remembering if it's add() append() push() to throw something onto an array in Python or Javascript. Knowing that clojure has a cool syntax or cool function-to-do-something isn't all that awesome when I need to just code something. If I was all in on a language and not a jack of all trades, I'd love those special features. As is, I like a simple list of reserved words that I have a half chance of remembering. Glad to see this funding concept worked for the community.

mijoharas 12y ago
I often have the same problems as you (and I have to say, I constantly forget whether it's push/append too, even in my most used languages). My solution to it has been to setup my development environment to provide the requisite autocompletion and linting (I use emacs with the brilliant spacemacs package to be able to have "the one ide for all languages"). It takes a bit of setting up for each language you use, but if you do that as primary setup on an as-and-when basis it's not that bad (and "starter-packs" that have packages that work together are great)
mijoharas 12y ago
I often have the same problems as you (and I have to say, I constantly forget whether it's push/append too, even in my most used languages). My solution to it has been to setup my development environment to provide the requisite autocompletion and linting (I use emacs with the brilliant spacemacs package to be able to have "the one ide for all languages"). It takes a bit of setting up for each language you use, but if you do that as primary setup on an as-and-when basis it's not that bad (and "starter-packs" that have packages that work together are great)
mijoharas 12y ago
I often have the same problems as you (and I have to say, I constantly forget whether it's push/append too, even in my most used languages). My solution to it has been to setup my development environment to provide the requisite autocompletion and linting (I use emacs with the brilliant spacemacs package to be able to have "the one ide for all languages"). It takes a bit of setting up for each language you use, but if you do that as primary setup on an as-and-when basis it's not that bad (and "starter-packs" that have packages that work together are great)

tluyben2 12y ago