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Gabriele 9-May-2007 [2172x3] | when you use parse in rebol to parse a block, you are creating a new grammar (not a new syntax). usually you tie the grammar to the semantics so you can easily compile or interpret it. but there is no requirement to be so. |
also, about your control natives point, i think that rebol needs 1 (or 2 at most) to be native. we have more because of performance only. | |
eg. you can do all control functions just using while. | |
Pekr 9-May-2007 [2175x3] | Sun releases sources to the community - http://www.eweek.com/article2/0,1895,2127458,00.asp |
There is also talk about JavaFX and Java FX Script, which should be used for mobile devices market, content creation ... | |
hmm, that scripting language has VID like declarative aproach - https://openjfx.dev.java.net/Getting_Started_With_JavaFX.html | |
Brock 9-May-2007 [2178] | maybe we can steal their GridPanel widget for View ;-) |
JaimeVargas 9-May-2007 [2179x3] | Gabriele, (f a b) in the macros context is not always a function application. Regarding PARSE, Scheme also has many parsers and lexesr on in the yacc/lex style and parser combinators. So you can assing any semantics or any syntax just like rebol. The fact is that any Turing complete PL can reproduce any other. I can easily see how to write a C compile in Rebol, and obviouly Rebol is written in C. The same holds for Scheme. Or any other language. So that is not a valid point of discussion imo. The thing with interpreters is that the tower of languages grows with each level and performace takes a hit with each layer of interpretation. The beauty of compilers is that once bootstrapped they can eliminate on layer, therefore gaining speed as they go directly to the hardware. |
Brian, I have not look into Icon, but I can put in my list of fringe languages to check ;-) | |
Anton, Thanks. I engaged on this debate because it helps me to understand better some concepts in PLD. | |
btiffin 9-May-2007 [2182] | Jaime; I get the impression you may really really like the challenge. It goes way deep. And check out the books. The Implementation of Icon book goes nitty gritty into PLD. |
JaimeVargas 9-May-2007 [2183x5] | All, I suggest you read this article from DrDobbs. It does a good job explaning syntax-case macros of Scheme. |
Building Little Languages with Macros or "Picking up where language designers leave off" http://www.ddj.com/dept/architect/184405618 | |
Excerpts: A syntax-case macro can perform arbitrary computation (using Scheme) on the results of a pattern match. A syntax-case macro does not manipulate plain text, or even plain symbols and lists (as does a Lisp macro). Instead, the macro manipulates syntax objects, which encode the lexical context and source locations of program fragments. Consequently, just like a syntax-rules macro, a syntax-case macro respects the lexical structure of the source program (by default) and it plays well with source-correlating tools. | |
Syntax objects enable the implementation of most any little language or language extension. Using syntax-case, we have implemented a Java-like class system for Scheme, lex- and yacc-like forms for building parsers, and constructs for defining and linking program components. Programmers using these constructs do not reason about them in terms of their expansion. Instead, syntax objects allow the expansion to be hidden behind abstract definitions of the constructs, just as the inner workings of any compiler are hidden behind a language definition. | |
A language's concrete syntax need not be parenthesized to make use of syntax objects. In particular, we are currently developing implementations of Java and ML for our programming environment, DrScheme (see "Fostering Little Languages," DDJ, March 2004). Since our parsing tools produce syntax objects, we can treat Java and ML like macro extensions of Scheme. These macro implementations resemble typical Java-to-Scheme and ML-to-Scheme compilers, but little additional work is needed to adapt our entire programming environment to new languages. | |
btiffin 9-May-2007 [2188] | Jaime; I'm a little confused by your use of fringe. I was not trying to say Icon was fringe. Far from it. It is the most complete, complex programming language on the planet IMHO. I only mentioned that it was not popular, because it includes features that are over the head of most programmers. Unless you also include Scheme as fringe, then I take back what I just said, and yes by number of adopters, Icon is fringe as well. :) |
Louis 9-May-2007 [2189] | Icon is nice. I was using Icon before coming to REBOL. What it lacked for me was communication abilities. |
btiffin 9-May-2007 [2190x2] | Yeah, Dr. Ralph was writing the language before "icons" :) The internet was still in the gopher phase. |
For a POSIX layer of Icon with easier TCP, check Unicon http://www.drones.com/unicon/ | |
JaimeVargas 10-May-2007 [2192] | Brian, Do not worry. I put Scheme, ML, Rebol, SmallTalk and Icon in the fringe category. Java, Python, Perl, C, etc are not fringe for me. |
btiffin 10-May-2007 [2193] | Thought so. :) Just had to be sure. For me fringe always means 'requires an uncommon form of thinking' leading to low adoption rates. |
BrianH 10-May-2007 [2194] | I used to use Icon as well, mostly for the things I use the REBOL parse dialect for now. |
btiffin 10-May-2007 [2195x3] | Where I see REBOL, scripting will always be the domain of the computer programmer, but the data model is so close to being the domain of everybody, I think we are one small (yet huge) step away. |
Icon is an awesome learning step for anyone thinking of languare design. But it does require being 'smarter than the average bear' :) | |
Brian; Cool. I'm still in BooBoo land when it comes to parse, but I can read and mod dialects now. Just not ready to write one. :) | |
BrianH 10-May-2007 [2198] | It was harder to debug Icon than any other language I've used. Not because the language required you to be smarter, but because error handling was badly designed. It always seemed ironic to me: In a language where "failure" was the name of a common control flow, real failure wasn't handled very well. |
btiffin 10-May-2007 [2199] | True...it could get pretty hairy, tracking the backtracking . |
BrianH 10-May-2007 [2200] | I never had any problem with the backtracking - that's where much of my understanding of PARSE control flow came from. The problem came when there was a real error, not an expected "failure", and it just backtracked like normal or worse, ignored it. |
btiffin 10-May-2007 [2201] | Brian; That's because you seem to be accepting of 'uncommon forms of thinking'. :) |
BrianH 10-May-2007 [2202] | Ain't that the truth :) |
btiffin 10-May-2007 [2203x2] | Like most rebols... |
I'm still going to push for LOAD/RELAX. It'll help make UIs that construction workers can feel empowered working with. I've seen it. A boss typing his own data in notepad, they get a real sense of being in charge, and not lead by the nose...Boss type personalities like to feel in charge of their surroundings. No other language I've seen even comes close. | |
BrianH 10-May-2007 [2205x2] | I still prefer the opposite. Did you see the discussions we had on the blog? If you modify my proposal for the additional parse operation in the way Volker suggested, by getting rid of the LOAD keyword, you can unify the block and string parse dialects. That way you can leverage the REBOL loader right in your parse rules but still fall back on string parsing if that doesn't work. |
And by fall back, I mean backtrack in the Icon sense. | |
btiffin 10-May-2007 [2207] | :) It's why I mentioned it... I like that approach...but I'd still like to be able to explain the scripts I write (in front of bosses) without going too techie. Maybe we'll get both :) |
BrianH 10-May-2007 [2208] | Do you have to do a line-by-line explanation, or can you give an overview? |
btiffin 10-May-2007 [2209x3] | Both. Line by line for the simpler, then I'll code a few lines and wait to see if they ask what the sequence is doing. |
It puts them in a very comfortable zone and in a head space where they can think about and request very specific options and outcomes. | |
And I don't have to write UIs that don't attack the problem at hand (their problem at hand, not the one I the coder nerd might be thinking). | |
Anton 11-May-2007 [2212] | Btiffin, from previous discussions, I'm probably with BrianH on this one. But I'd like it if you could come up with some scenarios from real life. Then each of us could try our approach to solving the problems and compare. |
Volker 11-May-2007 [2213] | load/relax can be written based on this: http://www.rebol.net/cookbook/recipes/0042.html ;) |
btiffin 11-May-2007 [2214] | Volker; Not sure. This type of thing happens when bosses type their own data...They don't really really need to type their own data, but it empowers them. 10-Mar-2007 $12,002.34 "Home Hardware" "Tile Saw" 1--Mar-2007 $12002.34 "Home Hardware" "Tile Saw" It's the fact that REBOL "knows" it's a syntax error, that got me to thinking about gibberish! or the invalid? test in the first place. I'd like to be able to show the user where the data failed, call notepad and let them try again. Now I just say try again and call notepad, can't help them much. |
Volker 11-May-2007 [2215x3] | text: { 10-Mar-2007 $12,002.34 "Home Hardware" "Tile Saw" 1--Mar-2007 $12002.34 "Home Hardware" "Tile Saw" } parse text blk-rule: [ some [ str: newline | #";" [thru newline | to end] new: (probe copy/part str new) | [#"[" | #"("] blk-rule | [#"]" | #")"] break | skip ( either attempt [ set [value new] load/next str ] [ probe :value ] [ new: find str " " print ["GIBBERISH" copy/part str new] ] ) :new ] ] |
based on that you can build your own load (add code to collect stuff in blocks) and add "spellchecking" in the gibberish-part. | |
ml-contest, smartest loader? :) | |
btiffin 11-May-2007 [2218] | Cool... |
Gabriele 14-May-2007 [2219x2] | Jaime, (f a b) *must* be quoted or be in a quoted list (maybe using the "funny" way of quoting available for macros ;) for it not being a function call. |
Jaime: you can write a REBOL interpreter in C but you can't compile REBOL to C. You can compile Scheme to REBOL but you can't compile REBOL to Scheme. The conclusion is that there is something in REBOL that Scheme lacks. If you make a language X that has the same features as REBOL, then it becomes easy to compile REBOL to X (X will need to be an interpreter - well, always assuming you don't have a special CPU that can make REBOL compilable). | |
Pekr 14-May-2007 [2221] | Gabriele - isn't it in fact big defficiency of Rebol, that it can't be compiled? That way we are one level slower than others, forever, no? :-) well, I probably oversimplified it few bits :-) I suspect that is the price for the ability to have self modifying code, but if I understand it correctly from what Jaime says, Scheme or Lisp are self-modifying too, yet those can be compiled .... Where is the difference? Any simple clarification for non low-level language person like me? |
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