Re: [Haskell-cafe] Design of a DSL in Haskell
Joerg, For definitions I'd search for Andres Loeh and haskell edsl. His PDF slides also have code examples which'll help. Lennart also gave a talk this year titled making edsls fly. The video is on the web. If you have specific questions bring them to the list! The community is a tremendous resource! -- Kim-Ee On Wed, Dec 5, 2012 at 2:09 PM, Joerg Fritsch frit...@joerg.cc wrote: Kim-Eeh, Tillmann, I am interested in the definition of deep vs shallow embedded, even if it is not featured in the Fowler textbook. Fowler that is one textbook only and I am not focused on it. --Joerg On Dec 5, 2012, at 2:59 AM, Kim-Ee Yeoh wrote: On Wed, Dec 5, 2012 at 8:32 AM, Tillmann Rendel ren...@informatik.uni-marburg.de wrote: I mean internal == embedded, independently of deep vs. shallow, following Martin Fowler [1]. [1] http://martinfowler.com/bliki/**DomainSpecificLanguage.htmlhttp://martinfowler.com/bliki/DomainSpecificLanguage.html If I look here [2] I see: An *internal DSL* is just a particular idiom of writing code in the host language. So a Ruby internal DSL is Ruby code, just written in particular style which gives a more language-like feel. As such they are often called *Fluent Interfaces* or*Embedded DSLs*. An *external DSL* is a completely separate language that is parsed into data that the host language can understand. Fowler places undue emphasis on the completely separate language, but other than that, the correspondence is clear. I wonder how he thinks about C implementing C? Or ghc implementing haskell in haskell? Would he say, Well, clearly C and haskell are not DSLs, they are general purpose languages!? [2] http://martinfowler.com/bliki/DslQandA.html -- Kim-Ee __**_ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/**mailman/listinfo/haskell-cafehttp://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
Hi Joerg,
Joerg Fritsch wrote:
I am interested in the definition of deep vs shallow embedded
I would say:
In shallow embedding, a DSL is implemented as a library. Every
keyword of the DSL is a function of the library. The
implementation of the function directly computes the result of
executing that keyword.
For example, here's a shallowly embedded DSL for processing
streams of integers:
{-# LANGUAGE TemplateHaskell #-}
module Stream where
import Prelude (Integer, (+), (*), (.))
import Language.Haskell.TH
data Stream = Stream Integer Stream
deriving Show
cycle x = Stream x (cycle x)
map f (Stream x xs) = Stream (f x) (map f xs)
There is one domain-specific type, Stream, and one
domain-specific operation, map. The body of map directly contains
the implementation of mapping over a stream. Correspondingly, DSL
programs are immediately evaluated to their values:
shallow :: Stream
shallow = map (+ 1) (map (* 2) (cycle 1))
In deep embedding, a DSL is implemented as a library. Every
keyword of the DSL is a function of the library. The implemention
of the function creates a structural representation of the DSL
program.
For example, here's a deeply embedded version of the above DSL:
data Program = Cycle Integer | Map (Integer - Integer) Program
Here, the domain-specific operations are data constructors. The example
program:
deep :: Program
deep = Map (+ 1) (Map (* 2) (Cycle 1))
We need a separate interpreter for actually executing the
program. The implementation of the interpreter can reuse cycle
and map from the shallow embedding:
eval :: Program - Stream
eval (Cycle x) = cycle x
eval (Map f p) = map f (eval p)
value :: Stream
value = eval deep
The benefit of deep embedding is that we can inspect the program,
for example, to optimize it:
optimize :: Program - Program
optimize (Cycle x) = Cycle x
optimize (Map f (Cycle x)) = Cycle (f x)
optimize (Map f (Map g s)) = optimize (Map (f . g) s)
value' :: Stream
value' = eval (optimize deep)
Tillmann
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Re: [Haskell-cafe] Design of a DSL in Haskell
Hi Tillmann, is a shallow embedded DSL == an internal DSL and a deeply embedded DSL == an external DSL or the other way around? --Joerg On Dec 3, 2012, at 11:40 PM, Tillmann Rendel wrote: Hi, Joerg Fritsch wrote: I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. You can already use Haskell in your DSL. A simple example: main = runCWMWL $ do eval (isFib::, 500 + 500, ?BOOL) The (+) operator is taken from Haskell, and it is available in your DSL program. This use of Haskell is completely for free: You don't have to do anything special with your DSL implementation to support it. I consider this the main benefit of internal vs. external DSLs. A more complex example: main = runCWMWL $ do foo - eval (isFib::, 1000, ?BOOL) if foo then return 27 else return 42 Here, you are using the Haskell if-then-else expression to decide which DSL program to run. Note that this example also uses (=) and return, so it only works because your DSL is monadic. Beyond writing the Monad instance, you don't have to do anything special to support this. In particular, you might not need an additional embed function if you've already implemented return from the Monad type class. I consider this the main benefit of the Monad type class. Tillmann ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
On Tue, Dec 4, 2012 at 4:53 PM, Joerg Fritsch frit...@joerg.cc wrote: is a shallow embedded DSL == an internal DSL and a deeply embedded DSL == an external DSL or the other way around? Roughly speaking, yes. But a deep DSL doesn't mean you've got to have a parser tokenizer IO input. You can get a deep DSL merely from the free monad construction. -- Kim-Ee On Tue, Dec 4, 2012 at 4:53 PM, Joerg Fritsch frit...@joerg.cc wrote: Hi Tillmann, is a shallow embedded DSL == an internal DSL and a deeply embedded DSL == an external DSL or the other way around? --Joerg On Dec 3, 2012, at 11:40 PM, Tillmann Rendel wrote: Hi, Joerg Fritsch wrote: I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. You can already use Haskell in your DSL. A simple example: main = runCWMWL $ do eval (isFib::, 500 + 500, ?BOOL) The (+) operator is taken from Haskell, and it is available in your DSL program. This use of Haskell is completely for free: You don't have to do anything special with your DSL implementation to support it. I consider this the main benefit of internal vs. external DSLs. A more complex example: main = runCWMWL $ do foo - eval (isFib::, 1000, ?BOOL) if foo then return 27 else return 42 Here, you are using the Haskell if-then-else expression to decide which DSL program to run. Note that this example also uses (=) and return, so it only works because your DSL is monadic. Beyond writing the Monad instance, you don't have to do anything special to support this. In particular, you might not need an additional embed function if you've already implemented return from the Monad type class. I consider this the main benefit of the Monad type class. Tillmann ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
In Haskell, shallow DSLs generate values - deep DSLs generate structures (typically abstract syntax trees), the structure can subsequently be used to generate a value (or a C program, or a HTML page, etc.). See Andy Gill and colleagues Types and Type Families for Hardware Simulation and Synthesis, The Internals and Externals of Kansas Lava for a fuller definition. http://www.ittc.ku.edu/csdl/fpg/sites/default/files/Gill-10-TypesKansasLava.pdf Other communities may have their own definitions. On 4 December 2012 10:01, Kim-Ee Yeoh k...@atamo.com wrote: On Tue, Dec 4, 2012 at 4:53 PM, Joerg Fritsch frit...@joerg.cc wrote: is a shallow embedded DSL == an internal DSL and a deeply embedded DSL == an external DSL or the other way around? Roughly speaking, yes. But a deep DSL doesn't mean you've got to have a parser tokenizer IO input. You can get a deep DSL merely from the free monad construction. -- Kim-Ee ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
Hi, Joerg Fritsch wrote: is a shallow embedded DSL == an internal DSL and a deeply embedded DSL == an external DSL or the other way around? I mean internal == embedded, independently of deep vs. shallow, following Martin Fowler [1]. Tillmann [1] http://martinfowler.com/bliki/DomainSpecificLanguage.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
Little things to check understanding: * ghc/ghci implements a DSL called Haskell -- does it do so in a deep or shallow way? * where are the shallow DSLs? the deep ones? (hint: some of them are right under our very noses!) -- Kim-Ee On Wed, Dec 5, 2012 at 12:49 AM, Stephen Tetley stephen.tet...@gmail.comwrote: In Haskell, shallow DSLs generate values - deep DSLs generate structures (typically abstract syntax trees), the structure can subsequently be used to generate a value (or a C program, or a HTML page, etc.). See Andy Gill and colleagues Types and Type Families for Hardware Simulation and Synthesis, The Internals and Externals of Kansas Lava for a fuller definition. http://www.ittc.ku.edu/csdl/fpg/sites/default/files/Gill-10-TypesKansasLava.pdf Other communities may have their own definitions. On 4 December 2012 10:01, Kim-Ee Yeoh k...@atamo.com wrote: On Tue, Dec 4, 2012 at 4:53 PM, Joerg Fritsch frit...@joerg.cc wrote: is a shallow embedded DSL == an internal DSL and a deeply embedded DSL == an external DSL or the other way around? Roughly speaking, yes. But a deep DSL doesn't mean you've got to have a parser tokenizer IO input. You can get a deep DSL merely from the free monad construction. -- Kim-Ee ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
On Wed, Dec 5, 2012 at 8:32 AM, Tillmann Rendel ren...@informatik.uni-marburg.de wrote: I mean internal == embedded, independently of deep vs. shallow, following Martin Fowler [1]. [1] http://martinfowler.com/bliki/**DomainSpecificLanguage.htmlhttp://martinfowler.com/bliki/DomainSpecificLanguage.html If I look here [2] I see: An *internal DSL* is just a particular idiom of writing code in the host language. So a Ruby internal DSL is Ruby code, just written in particular style which gives a more language-like feel. As such they are often called *Fluent Interfaces* or*Embedded DSLs*. An *external DSL* is a completely separate language that is parsed into data that the host language can understand. Fowler places undue emphasis on the completely separate language, but other than that, the correspondence is clear. I wonder how he thinks about C implementing C? Or ghc implementing haskell in haskell? Would he say, Well, clearly C and haskell are not DSLs, they are general purpose languages!? [2] http://martinfowler.com/bliki/DslQandA.html -- Kim-Ee __**_ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/**mailman/listinfo/haskell-cafehttp://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
Kim-Eeh, Tillmann, I am interested in the definition of deep vs shallow embedded, even if it is not featured in the Fowler textbook. Fowler that is one textbook only and I am not focused on it. --Joerg On Dec 5, 2012, at 2:59 AM, Kim-Ee Yeoh wrote: On Wed, Dec 5, 2012 at 8:32 AM, Tillmann Rendel ren...@informatik.uni-marburg.de wrote: I mean internal == embedded, independently of deep vs. shallow, following Martin Fowler [1]. [1] http://martinfowler.com/bliki/DomainSpecificLanguage.html If I look here [2] I see: An internal DSL is just a particular idiom of writing code in the host language. So a Ruby internal DSL is Ruby code, just written in particular style which gives a more language-like feel. As such they are often called Fluent Interfaces orEmbedded DSLs. An external DSL is a completely separate language that is parsed into data that the host language can understand. Fowler places undue emphasis on the completely separate language, but other than that, the correspondence is clear. I wonder how he thinks about C implementing C? Or ghc implementing haskell in haskell? Would he say, Well, clearly C and haskell are not DSLs, they are general purpose languages!? [2] http://martinfowler.com/bliki/DslQandA.html -- Kim-Ee ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
(Sorry, forgot to reply to the list initially; see conversation below.) On Mon, Dec 03, 2012 at 03:49:00PM +0100, Joerg Fritsch wrote: Brent, I believe that inside the do-block (that basically calls my interpreter) I cannot call any other Haskell function that are not recognized by my parser and interpreter. This seems to just require some sort of escape mechanism for embedding arbitrary Haskell code into your language. For example a primitive embed :: a - CWMWL a (assuming CWMWL is the name of your monad). Whether this makes sense, how to implement embed, etc. depends entirely on your language and interpreter. However, as you imply below, this may or may not be possible depending on the type a. In that case I suggest making embed a type class method. Something like class Embeddable a where embed :: a - CWMWL a I still get the feeling, though, that I have not really understood your question. I am also trying to learn how I could preserve state from one line of code of my DSL to the next. I understand that inside the interpreter one would use a combination of the state monad and the reader monad, but could not find any non trivial example. Yes, you can use the state monad to preserve state from one line to the next. I am not sure what you mean by using a combination of state and reader monads. There is nothing magical about the combination. You would use state + reader simply if you had some mutable state as well as some read-only configuration to thread through your interpreter. xmonad is certainly a nontrivial example but perhaps it is a bit *too* nontrivial. If I think of any other good examples I'll let you know. -Brent On Dec 3, 2012, at 1:23 PM, Brent Yorgey wrote: On Sun, Dec 02, 2012 at 03:01:46PM +0100, Joerg Fritsch wrote: This is probably a very basic question. I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. I don't think I understand the question. The above already *is* real Haskell. What is there to escape? I thought of providing a defautl-wrapper for some required prelude functions (such as print) inside my interpreter but I wonder if there are more elegant ways to co-loacate a DSL and Haskell without falling back to being a normal library only. I don't understand this sentence either. Can you explain what you are trying to do in more detail? -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
Thanks Brent, my question is basically how the function embed would in practice be implemented. I want to be able to take everything that my own language does not have from the host language, ideally so that I can say: evalt - eval (isFib::, 1000, ?BOOL)) case evalt of Left Str - Right Str - or so. --Joerg On Dec 3, 2012, at 4:04 PM, Brent Yorgey wrote: (Sorry, forgot to reply to the list initially; see conversation below.) On Mon, Dec 03, 2012 at 03:49:00PM +0100, Joerg Fritsch wrote: Brent, I believe that inside the do-block (that basically calls my interpreter) I cannot call any other Haskell function that are not recognized by my parser and interpreter. This seems to just require some sort of escape mechanism for embedding arbitrary Haskell code into your language. For example a primitive embed :: a - CWMWL a (assuming CWMWL is the name of your monad). Whether this makes sense, how to implement embed, etc. depends entirely on your language and interpreter. However, as you imply below, this may or may not be possible depending on the type a. In that case I suggest making embed a type class method. Something like class Embeddable a where embed :: a - CWMWL a I still get the feeling, though, that I have not really understood your question. I am also trying to learn how I could preserve state from one line of code of my DSL to the next. I understand that inside the interpreter one would use a combination of the state monad and the reader monad, but could not find any non trivial example. Yes, you can use the state monad to preserve state from one line to the next. I am not sure what you mean by using a combination of state and reader monads. There is nothing magical about the combination. You would use state + reader simply if you had some mutable state as well as some read-only configuration to thread through your interpreter. xmonad is certainly a nontrivial example but perhaps it is a bit *too* nontrivial. If I think of any other good examples I'll let you know. -Brent On Dec 3, 2012, at 1:23 PM, Brent Yorgey wrote: On Sun, Dec 02, 2012 at 03:01:46PM +0100, Joerg Fritsch wrote: This is probably a very basic question. I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. I don't think I understand the question. The above already *is* real Haskell. What is there to escape? I thought of providing a defautl-wrapper for some required prelude functions (such as print) inside my interpreter but I wonder if there are more elegant ways to co-loacate a DSL and Haskell without falling back to being a normal library only. I don't understand this sentence either. Can you explain what you are trying to do in more detail? -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
The below is probably not a good example since it does not require a DSL but the principle is clear that I want to take things from teh host language that I do not have implemented (yet) in my DSL. --Joerg On Dec 3, 2012, at 4:25 PM, Joerg Fritsch wrote: Thanks Brent, my question is basically how the function embed would in practice be implemented. I want to be able to take everything that my own language does not have from the host language, ideally so that I can say: evalt - eval (isFib::, 1000, ?BOOL)) case evalt of Left Str - Right Str - or so. --Joerg On Dec 3, 2012, at 4:04 PM, Brent Yorgey wrote: (Sorry, forgot to reply to the list initially; see conversation below.) On Mon, Dec 03, 2012 at 03:49:00PM +0100, Joerg Fritsch wrote: Brent, I believe that inside the do-block (that basically calls my interpreter) I cannot call any other Haskell function that are not recognized by my parser and interpreter. This seems to just require some sort of escape mechanism for embedding arbitrary Haskell code into your language. For example a primitive embed :: a - CWMWL a (assuming CWMWL is the name of your monad). Whether this makes sense, how to implement embed, etc. depends entirely on your language and interpreter. However, as you imply below, this may or may not be possible depending on the type a. In that case I suggest making embed a type class method. Something like class Embeddable a where embed :: a - CWMWL a I still get the feeling, though, that I have not really understood your question. I am also trying to learn how I could preserve state from one line of code of my DSL to the next. I understand that inside the interpreter one would use a combination of the state monad and the reader monad, but could not find any non trivial example. Yes, you can use the state monad to preserve state from one line to the next. I am not sure what you mean by using a combination of state and reader monads. There is nothing magical about the combination. You would use state + reader simply if you had some mutable state as well as some read-only configuration to thread through your interpreter. xmonad is certainly a nontrivial example but perhaps it is a bit *too* nontrivial. If I think of any other good examples I'll let you know. -Brent On Dec 3, 2012, at 1:23 PM, Brent Yorgey wrote: On Sun, Dec 02, 2012 at 03:01:46PM +0100, Joerg Fritsch wrote: This is probably a very basic question. I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. I don't think I understand the question. The above already *is* real Haskell. What is there to escape? I thought of providing a defautl-wrapper for some required prelude functions (such as print) inside my interpreter but I wonder if there are more elegant ways to co-loacate a DSL and Haskell without falling back to being a normal library only. I don't understand this sentence either. Can you explain what you are trying to do in more detail? -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
Hi, Joerg Fritsch wrote: I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. You can already use Haskell in your DSL. A simple example: main = runCWMWL $ do eval (isFib::, 500 + 500, ?BOOL) The (+) operator is taken from Haskell, and it is available in your DSL program. This use of Haskell is completely for free: You don't have to do anything special with your DSL implementation to support it. I consider this the main benefit of internal vs. external DSLs. A more complex example: main = runCWMWL $ do foo - eval (isFib::, 1000, ?BOOL) if foo then return 27 else return 42 Here, you are using the Haskell if-then-else expression to decide which DSL program to run. Note that this example also uses (=) and return, so it only works because your DSL is monadic. Beyond writing the Monad instance, you don't have to do anything special to support this. In particular, you might not need an additional embed function if you've already implemented return from the Monad type class. I consider this the main benefit of the Monad type class. Tillmann ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
On Sun, Dec 2, 2012 at 7:31 PM, Joerg Fritsch frit...@joerg.cc wrote: This is probably a very basic question. I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. I thought of providing a defautl-wrapper for some required prelude functions (such as print) inside my interpreter but I wonder if there are more elegant ways to co-loacate a DSL and Haskell without falling back to being a normal library only. --Joerg +1 I am also interested in the DSL-in-Haskell possibilities [I am assuming Joerg that you're familiar with the basic ideas and terminology like http://martinfowler.com/bliki/DomainSpecificLanguage.html and the links therein] Rusi -- http://www.the-magus.in http://blog.languager.org ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Design of a DSL in Haskell
Rusi, I have read Fowler's book.(that is focusing on Java by the way) and could not find the answer there, I think it is a typical textbook. I think this is a good start by the way: http://www.cse.chalmers.se/edu/year/2011/course/TIN321/lectures/bnfc-tutorial.html --Joerg On Dec 2, 2012, at 5:45 PM, Rustom Mody wrote: On Sun, Dec 2, 2012 at 7:31 PM, Joerg Fritsch frit...@joerg.cc wrote: This is probably a very basic question. I am working on a DSL that eventuyally would allow me to say: import language.cwmwl main = runCWMWL $ do eval (isFib::, 1000, ?BOOL) I have just started to work on the interpreter-function runCWMWL and I wonder whether it is possible to escape to real Haskell somehow (and how?) either inside ot outside the do-block. I thought of providing a defautl-wrapper for some required prelude functions (such as print) inside my interpreter but I wonder if there are more elegant ways to co-loacate a DSL and Haskell without falling back to being a normal library only. --Joerg +1 I am also interested in the DSL-in-Haskell possibilities [I am assuming Joerg that you're familiar with the basic ideas and terminology like http://martinfowler.com/bliki/DomainSpecificLanguage.html and the links therein] Rusi -- http://www.the-magus.in http://blog.languager.org ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
