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Parse query

 [1/6] from: jrdrp::blueyonder::co::uk at: 11-Nov-2001 22:27


Hi all, How can I use parse to extract particular subtrings from a string e.g. telephone no (NNN-NNN-NNNN), date (DD/MM/YYYY). digit: charset "0123456789" str: "abcdefgh 09/11/2001 xyz" parse str [to 2 digit "/" 2 digit "/" 4 digit copy datestr to end] returns false. Does the to keyword only support simple character string arguments? Should I use find function instead/ TIA John

 [2/6] from: al:bri:xtra at: 12-Nov-2001 16:25


John wrote:
> How can I use parse to extract particular subtrings from a string e.g.
telephone no (NNN-NNN-NNNN), date (DD/MM/YYYY). Try something like: Digit: charset "0123456789" str: "abcdefgh 09/11/2001 xyz" Date: [ copy Day 2 Digit #"/" copy Month 2 Digit #"/" copy Year 2 4 Digit ] Telephone: [ copy Number [ 3 Digit #"-" 3 Digit #"-" 4 Digit ] ] parse str [ Date | Telephone | skip ]
> Does the to keyword only support simple character string arguments?
Yes. It's been requested to feedback that more interesting arguments be supported.
> Should I use find function instead?
'parse is nicer to use, once you use 'skip. :-) Andrew Martin ICQ: 26227169 http://valley.150m.com/

 [3/6] from: jrdrp:blueyonder at: 12-Nov-2001 11:25


Andrew, Thanks but this doesn't seem to work. The REBOL parse documentation does not look very comprehensive to me for a feature which is obviously very powerful. I am not clear from reading it how your rules starting with copy are intended to work. Also can the rules enforce specific character sequences e.g. dd/mm/yyyyy because my reading of a rule like 2 digit "/" 2 digit "/" 4 digit is that it would allow values like 31 /01/ 1997 i.e. embedded white space between terms? John

 [4/6] from: petr:krenzelok:trz:cz at: 12-Nov-2001 12:51


John R wrote:
> Andrew, > Thanks but this doesn't seem to work.
<<quoted lines omitted: 5>>
> 2 digit "/" 2 digit "/" 4 digit is that it would allow values like > 31 /01/ 1997 i.e. embedded white space between terms?
I don't follow the thread, so I can possibly miss the point, but as for above example - yes, white spaces would be allowed. If you want to prevent that, use parse in more precise way - parse/allĘ: ->> help parse USAGE: PARSE input rules /all /case DESCRIPTION: Parses a series according to rules. PARSE is a native value. ARGUMENTS: input -- Input series to parse (Type: series) rules -- Rules to parse by (Type: block string none) REFINEMENTS: /all -- Parses all chars including spaces. ^^^^^^^ /case -- Uses case-sensitive comparison. PS - as for single char delimiters, try following: ->> parse "11/01/1999" "/" == ["11" "01" "1999"] ->> parse "+420-605/111222" "-/" == ["+420" "605" "111222"] Cheers, -pekr-

 [5/6] from: lmecir:mbox:vol:cz at: 12-Nov-2001 13:07


Hi John, << (...) Also can the rules enforce specific character sequences e.g. dd/mm/yyyyy because my reading of a rule like 2 digit "/" 2 digit "/" 4 digit is that it would allow values like 31 /01/ 1997 i.e. embedded white space between terms? John (...)
>>
you can go like this: digit: charset [#"0" - #"9"] date: [2 digit #"/" 2 digit #"/" 5 digit] dates: copy [] all-dates: [any [copy one-date date (append dates one-date) | skip]] ; notice the /all refinement enabling you to control spaces parse/all "abcv 12/01/20001 ffdsa 03/06/30002 31/ 01/40005" all-dates dates == ["12/01/20001" "03/06/30002"] Cheers Ladislav

 [6/6] from: jrdrp:blueyonder at: 12-Nov-2001 13:21


Ladislav, Petr, Andrew, Thanks for the help on parse - I can see now what I should be doing! Thanks also to Brett Handley for his useful "Parse Tutorial". John

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