[erlang-questions] string to tupple ?

Sean Cribbs <>
Sun Jun 20 23:00:38 CEST 2010


If you want to be more formal about it, both neotoma and leex/yecc
would make short work of that format.  Just out of curiosity, any
reason why you can't use a mysql driver for Erlang (instead of going
to the trouble of parsing)?

Here's a small grammar in neotoma's PEG format (untested):

coord_list <- pair ("," pair)* `[ hd(Node) | [P || [",", P] <- tl(Node)] ]`;
pair <- "(" number "," number ")" `{lists:nth(2,Node), lists:nth(4,Node)}`;
number <- [0-9]+ `list_to_integer(Node)`;

Sean

On Sun, Jun 20, 2010 at 1:50 PM, Rapsey <> wrote:
> The best representation depends on what operations you need to perform. List
> of tuples or just a plain list of integers would most likely be best.
> Parsing that format is pretty easy:
>
> L = string:tokens("(a,b),(c,d),(e,f)","(),").
> [list_to_integer(C) || C <- L].
>
>
> Sergej
>
> On Sun, Jun 20, 2010 at 7:43 PM, info <> wrote:
>
>> After a few manipulation with list, string, I broke my head with this
>> problem.
>>
>> I extract from a mysql database a list representing a list of coordinates.
>> The string is like this "(a,b),(c,d),(e,f) ......."
>> I would like to transform this string in order to easily manipulate each
>> coordinate.
>> What is the best representation in erlang ?
>> - a list of tupples : if yes how to transform it in [{a,b},{c,d},{e,f},
>> ....]
>> - other representations ?
>>
>> John
>>
>


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