How would I do regex matching in Erlang?
All I know is this: f("AAPL" ++ Inputstring) -> true.
The lines that I need to match "AAPL,07-May-2010 15:58,21.34,21.36,21.34,21.35,525064\n"
In Perl regex: ^AAPL,* (or something similar)
In Erlang?
4
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In this case the example you give WILL match the string so I assume that you are really after a more general case. In that case use the 're' module as has been answered.rvirding– rvirding2010-05-14 12:02:43 +00:00Commented May 14, 2010 at 12:02
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If you're just matching the first five exact characters of a string, regex is about the slowest and most complicated way you can do it.Dustin– Dustin2010-05-14 16:55:09 +00:00Commented May 14, 2010 at 16:55
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@Dustin the first five characters are dynamic. So what do you suggest?Lydon Ch– Lydon Ch2010-05-15 03:35:15 +00:00Commented May 15, 2010 at 3:35
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It's not clear what you mean when you say the characters are dynamic. For the example you've given, there's no language in which I'd use a regex. The match is too simple.Dustin– Dustin2010-05-15 08:30:28 +00:00Commented May 15, 2010 at 8:30
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1 Answer
Use the re module, e.g.:
...
String = "AAPL,07-May-2010 15:58,21.34,21.36,21.34,21.35,525064\n",
RegExp = "^AAPL,*",
case re:run(String, RegExp) of
{match, Captured} -> ... ;
nomatch -> ...
end,
...
4 Comments
viraptor
Equivalent to
re:run(String, RegExp)
Lydon Ch
How is this different to running => regexp:first_match(Line, "^AAPL,*" ) ?
3lectrologos
Well, it may not be different, but according to the regexp module documentation 'it has been obsoleted by the re module and will be removed in a future release'. So, you should definitely prefer the re module.
gextra
just to precise, the match in the case clause is actually {match,ListOfMatchArea} where ListOfMatchArea is in the form [{A,B}]