World: r3wp
[Parse] Discussion of PARSE dialect
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Gregg 13-Jan-2006 [833] | Thanks Ladislav! |
Rebolek 1-Mar-2006 [834] | Is it possible to use "<" ">" and so on in parse rules? (not in string parse). |
Anton 1-Mar-2006 [835x2] | What are you trying to parse ? |
I think the answer is no, but I am not sure of the question yet. Please give an example input. | |
Rebolek 1-Mar-2006 [837x3] | I'm trying to parse something as simple as 1 < 2. |
hm it's possible with any-word! ... | |
but that does not help me very much | |
Anton 1-Mar-2006 [840] | Yes, I'm not having much luck here. |
Rebolek 1-Mar-2006 [841] | Probably it's something like Oldes' comma problem. :/ |
Gabriele 1-Mar-2006 [842] | >> lt: to lit-word! first [ < ] == '< >> parse [1 < 2] [number! lt number!] == true |
Rebolek 1-Mar-2006 [843x3] | great, thanks! |
actually not great, but working :) | |
Unfortunately, there's probably no similar trick that can be used with comma, poor Oldes | |
Volker 1-Mar-2006 [846] | replace/all str "," comma " ; :)) |
Oldes 1-Mar-2006 [847] | you cannot use this in a dialect! |
Volker 1-Mar-2006 [848] | before i load the string! But not too reliable, if you have "," in strings. |
Oldes 1-Mar-2006 [849] | and I'm not such a poor:-) I am using double parenthesis in my dialect instead of using commas (it's ugly, but it's working) |
Volker 1-Mar-2006 [850] | how does some sample code look? |
Oldes 1-Mar-2006 [851x2] | I still think it's a shame, that we cannot load strings with commas, so we cannot forexample parse javascript or actionscript |
my code looks like doSomeFunction(("a" add b) 1) | |
Volker 1-Mar-2006 [853] | i think that is hard to do perfectly. for example "\"", how to parse that? |
Oldes 1-Mar-2006 [854] | in actionscript it's doSomeFunction("a" add b, 1) |
Volker 1-Mar-2006 [855] | doSomeFunction("a" add b # 1) doSomeFunction("a" add b . 1) ? |
Oldes 1-Mar-2006 [856x2] | I know it woud be possible to improve my dialect, but I'm not going to do it in near future, I'm already used to write it this way:) |
I think it's quite logical to close it in parenthesis than using chars like # | |
Volker 1-Mar-2006 [858] | But chars like # are easier to search/replace. But i dont defend my solution, yours looks ok. Do you write your dialect-code in rebol-blocks or in a string? |
Oldes 1-Mar-2006 [859x4] | And for the Rebolek: I use in RSWF this: |
slash: to-lit-word first [/] dslash: to-lit-word "//" rShift: to-lit-word ">>" UrShift: to-lit-word ">>>" _bigger: to-lit-word ">" _less: to-lit-word "<" _noteql: to-lit-word "<>" _lesseql: to-lit-word "<=" _biggeql: to-lit-word ">=" | |
and then: | |
'* (term-op: [ins-act #{0C}]) | slash (term-op: [ins-act #{0D}]) ;Divide | dslash (term-op: [ins-act #{3F}]) ;Modulo | rShift (term-op: [ins-act #{64}]) ;RShift | UrShift (term-op: [ins-act #{65}]);UnsignedRShift | lShift (term-op: [ins-act #{63}]) ;lShift | '| (term-op: [ins-act #{61}]) ;bitwise OR | ['|| | 'or] (term-op: [ins-act #{11}]);OR | ['& | 'band] (term-op: [ins-act #{60}]) ;bitwise AND | 'and (term-op: [ins-act #{10}]) ;AND | |
Rebolek 1-Mar-2006 [863] | Thanks Oldes, that should help me |
Oldes 1-Mar-2006 [864x2] | Volker: blocks |
it's much more easier as you can use Rebol's datatypes | |
Volker 1-Mar-2006 [866] | i thought about something like "js-load string" which would do the comma-conversion. But if your dialect works, no need for extra work. |
Rebolek 1-Mar-2006 [867] | maybe fixing REBOL should be better? If "." can work without problem, why not "," ? |
Volker 1-Mar-2006 [868] | interesting question why it is left out. but you would have other problems too, although not that often. like "\"". in rebol that is "\" " . in javascript "^"" |
Rebolek 1-Mar-2006 [869] | Volker this is some special case, you can replace that before parsing string, but you cannot replace all commas in action script, some of them may be parts of string |
Rondon 2-Mar-2006 [870x2] | Does anybody have an script to parse BNFs? |
BHF's specification.. | |
Gregg 3-Mar-2006 [872] | I think Bretty Handley did. Check codeconscious. |
Rebolek 5-Mar-2006 [873] | I think this should print 5 and return 'true. But it does not. >> parse [1 2 3 4 5][any number! set val number! (print val)] == false Help please? :) |
Anton 5-Mar-2006 [874x2] | >> parse [1 2 3 4 5][any [set val number!] (if value? 'val [print val])] 5 == true |
What you did was consume the five numbers, then try to set val to a sixth one. | |
Rebolek 5-Mar-2006 [876] | What I want is work with first four numbers and not with the last one |
Anton 5-Mar-2006 [877] | Is it always 5 numbers ? |
Rebolek 5-Mar-2006 [878] | No :( |
Anton 5-Mar-2006 [879] | >> parse [1 2 3 4 5][4 [set val number! (print val)] number!] 1 2 3 4 == true |
Rebolek 5-Mar-2006 [880] | Actually, the real elements may be very different. I just simplified the example. |
Anton 5-Mar-2006 [881] | Ok, so you don't know how many numbers you have until you fail to find another one. |
Rebolek 5-Mar-2006 [882] | I want to process all elements excluding the last one. |
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