World: r3wp
[Parse] Discussion of PARSE dialect
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Steeve 11-Nov-2008 [3151] | if we take in acount his defintion: none consumming rule. Then something like REPLAY or REWIND is more adapted. |
BrianH 11-Nov-2008 [3152x4] | AND comes from the use of & in the PEG syntax papers, but it could also be seen as being like the AND operator in REBOL, prefixed. |
Nonetheless, I agree that the names of AND and OF don't make much sense. The concept behind AND is sound though. | |
I have finally adapted Gabriele's DO proposal. Aside from naming issues, examples in need of explanation and any nagging questions we might be done here, with the exception of feedback from Carl about his proposals and any other issues. Anything else? | |
Added Chris's suggestion for AND to be named AT, and explained the advanced AND example (good luck!). If there aren't any more suggestions, I think this is ready to go to Carl. | |
Steeve 11-Nov-2008 [3156x2] | nothing about my ALL ? |
sob... | |
BrianH 11-Nov-2008 [3158] | I need to talk to Carl - it's a variant of his OF proposal, which probably isn't done yet. I'll bring it up :) |
Steeve 11-Nov-2008 [3159] | ok, good luck |
BrianH 11-Nov-2008 [3160] | I edited the OF proposal to provide a syntax description similar to the other proposals and added your suggestion, Steeve. |
Steeve 11-Nov-2008 [3161] | thanks |
Pekr 11-Nov-2008 [3162] | the parse doc is becoming scary precise :-) I hope Carl is not scared by the amount of requests :-) Can't wait to do similar job to low level View. Maybe we could start :-) |
BrianH 12-Nov-2008 [3163] | Maybe we're already working on low-level View :) |
Pekr 12-Nov-2008 [3164x4] | ah, can't believe that :-) But - Cyphre would be involved, no? And AFAIK he is not :-) |
Well then - transparent top window would be fine, but I think that more importantly - proper Unicode display should be a priority, and maybe looking at R3 alpha demo called button colors - it scrolls like molasses - there is either bug and there is more being redrawn than what is needed, or we have to think about other optimisations (e.g. I remember some 2 years ago Carl stating, that View might still render unnecessary things ...) | |
uh, wrong group, sorry ... | |
... another option I remember was to switch to compound rasterizer of AGG. And - REBOL timers are still substandard of what can be achieved imo ... But, as Carl said - those parts are going to be host part, hence open-source. We just need Carl to release sources. Hopefully it happens till I retire :-) (eventual replies to REBOL3 group, just wanted my comments to be at one channel) | |
BrianH 12-Nov-2008 [3168] | Cyphre is a member of the development world for the new GUI. |
[unknown: 5] 12-Nov-2008 [3169] | How many are working on REBOL3? |
Pekr 12-Nov-2008 [3170] | 1 - Carl .... |
[unknown: 5] 12-Nov-2008 [3171] | ;-) |
Pekr 12-Nov-2008 [3172x3] | In the past, there were Gabriele and Cyphre. Gab did initial VID3, http protocol and maybe other things. Cyphre did View kernel things - e.g. whole compositing engine was replaced by the better one - AGG based ... |
nowadays Henrik and BrianH are helping with VID 3.4. | |
uh, once again, I thought that I am in REBOL3 group ... | |
[unknown: 5] 12-Nov-2008 [3175] | heh. We can move this there. |
BrianH 12-Nov-2008 [3176x2] | Peta seems to have agreed with you, Chris, and changed the name of AND to AT. Things have settled down to grammar fixes. |
Carl has been notified that the proposals seem to have solidified. | |
Steeve 13-Nov-2008 [3178x3] | what doest it mean Brian ? (to have solidified) |
ah ok, you notified Carl, not he notified you | |
i hope he will keep some ideas... | |
BrianH 13-Nov-2008 [3181] | That would be nice. Check out the example at the end: No explicit failing, no position setting, no errors :) |
Steeve 13-Nov-2008 [3182x6] | Brian, it seems that when a file is parsed instead of a sub-directory, then your script duplicate the previous sub-directory |
except if change acts only when the nexrt rule is fullfilled (forget my remark) | |
it's a little be tricky to handle all the possible combinations, but the new commands seem really powerfull | |
i wonder if some CHANGE syntax combinations can be removed. expecially those one with the post-rule modifier. AT command should be enought to specify where the change must apply. AT rule change value ; to modify the index before the rule rule change value ; to modify the index after the rule | |
and in your example, to return back even after the change. at rule at change value | |
so that the CHANGE syntax could be simplified | |
BrianH 14-Nov-2008 [3188x2] | The AT is a separate operation that says "recognize this rule AT the current position but don't advance". AT doesn't specify a position. |
The CHANGE syntax already has been simplified :) | |
Steeve 14-Nov-2008 [3190] | what do u mean ? I never said that AT need or specify a position. My remark stay valid: change command syntax can be simplified but if you say that's already done. It's Ok. |
BrianH 14-Nov-2008 [3191x5] | CHANGE basically needs the same information that the CHANGE REBOL function needs: - A start series/position - An end position or length - A value to replace with - Some options, if you need them The CHANGE proposal has all those, and there isn't much more we can simplify it :) |
The rule matching is a bonus :) | |
Kind of a necessary bonus though, since it lets you specify what you want to change. You need to have the change operation before the rule so you know where the rule starts and where it ends. | |
I mean that you have to have the change keyword physically before the rule is affects because all of the PARSE operations are prefix. | |
is -> it This isn't my day :( | |
Chris 15-Nov-2008 [3196x5] | If I'm getting this right, OF is designed to do this: blk: [1 two 3.0] parse blk [of [integer! word! decimal!]] == true parse blk [of [number! word!]] == false (only accounts for one number) parse blk [of [word! decimal! string! issue! integer!] == true (can be none if a given type is missing) I have another scenario to which the word 'of would apply. There are situations where I want to match one item from a block of options. Currently, those options need to be pipe-separated, requiring preprocessing if those options come from a data source (see languages: in my emit-rss script for an example). This appears in both string and block parsing. An example (using IN as the hypothetical operator): m28: ["Feb"] m30: join m28 ["Apr" "Jun" "Sep" "Nov"] m31: join m30 ["Jan" "Mar" "May" "Jul" "Aug" "Oct" "Dec"] b28: repeat x 28 [append [] 29 - x] b30: repeat x 30 [append [] 31 - x] b31: repeat x 31 [append [] 32 - x] parse date-str [ in b28 "-" in m28 | in b30 "-" in m30 | in b31 "-" in m31 ] This would be true for "1-Jan" "30-Sep" and false for "31-Feb". |
Also, the way 'of works is a little like my 'match syntax (in QM, also designed for dialects), the difference being a resultant object instead of a block: match ["Click Here" #"h" http://click.here/][ href: file! | url! | path! title: string! id: opt issue! class: any refinement! accesskey: opt char! ] | |
An equivalent might be: parse ["Click Here" #"h" http://click.here/][ of [ [file! | url! | path!] string! opt issue! any refinement! opt char! ] ] | |
Though it'd raise other questions, I suppose -- what if the block were: ["Click Here" #"h" other: %click/here] It'd fail, as set-word! is not included in the spec? | |
It's complex to explain (or document), but is versatile and consise (for what it does). | |
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