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[REBOL] Re: Building an Associate List from a string

From: carl:cybercraft at: 24-Dec-2003 22:42

On 21-Oct-03, Tom Conlin wrote:
> On Mon, 20 Oct 2003, Tim Johnson wrote: >> Hello REBOLS: >> I need some advice :-) >> I've written a function that converts a delimited string into >> an associative list. >> Code and example console session is below: >> ;; >> make-al: function[ {Builds an associative list from a delimited >> string} >> str[string!] {delimited string} >> /with delimiter[string! char!] {custom delimiter (TAB is >> default)} >> /default _dval[any-type!] {custom default value (NONE is >> default)} >> ][tmp al-block sep dval][ >> sep: either with[to-string delimiter][to-string TAB] >> dval: either default[_dval][none] >> al-block: copy [] >> tmp: parse/all str sep >> if not even? length? tmp[append tmp dval] >> foreach [name value] tmp[ >> append al-block to-word name >> append al-block value >> ] >> al-block >> ] >> test: "age^-54^-name^-Tim Johnson^-occuptation^-coder" >> probe make-al test >> ;; = Console session >> == [age "54" name "Tim Johnson" occuptation "coder"] >> ;; Now, so far it is a piece of cake, but this is where >> ;; I falter: >> I would like to employ a strategy that converts any value >> to the best guess for a rebol datatype. IOWS, "54"[string!] >> would become 54[integer!] >> It occurs to me that a brute-force method would be to process >> via a nested attempt[any[]] loop. >> Any more "elegant" ideas? >> thanks >> tim > could try > append al-block load value
Hmm - I should've looked at the function properly. :) (See my previous post, which you can disregard due to what I say below about syntax errors using load.) With "... load value" as Tom suggests above, names such as "Tim Johnson" would be converted to two words and not a string, so a check for spaces and perhaps other characters would be needed to prevent that. ie, you'd return a string if a space was discovered. Another problem would be syntax errors when load hits text it can't recognise as a valid datatype. So, an error check would be needed too, with a string returned if you did get an error. I get the feeling though you'd be better to force what datatype they should be based on the names encounted, (ie, age = decimal, occupation = string), as the format of your data may not ever be quite right to always do a correct conversion. -- Carl Read