Re: [O] R code block produces only partial output

[Nick Dokos]

Nick Dokos <address@hidden> writes:

> John Hendy <address@hidden> writes:
>
>> On Tue, Aug 5, 2014 at 2:02 PM, Eric Schulte <address@hidden> wrote:
>>> Charles Berry <address@hidden> writes:
>>>
>>>> Eric Schulte <schulte.eric <at> gmail.com> writes:
>>
>> [snip]
>>
>>>> Eric,
>>>>
>>>> As noted by Andreas and John this is a problem for session output.
>>>>
>>>> org-babel-R-evaluate-session uses
>>>>
>>>>  (string-match "^\\([ ]*[>+\\.][ ]?\\)+\\([[0-9]+\\|[ ]\\)" line)
>>>>
>>>> to find the start of R output in the session.
>>>>
>>>> This does not match the `          0', but matches the `         .6'
>>>> in the output you show above, so if that had been in a session, all the
>>>> output up to and including the '.' before the '6' would be clipped
>>>> by the following
>>>>
>>>>   (substring line (match-end 1))
>>>>
>>>>
>>>> as Andreas output showed.
>>>>
>>>> Deleting the "\\." fixes Andreas case, but what are the circumstances
>>>> requiring the  "\\." ?
>>>>
>>>
>>> I don't know.
>>
>> I'm not sure either, but was curious if someone could translate the
>> regex into "plain language." Maybe I could observe some typical
>> outputs and chime in since I use R regularly? From noob-level regex
>> stuff, it's looking for a new line followed by some number of spaces,
>> a ">" and at least one period and numbers?
>>
>
> It says[fn:1]
>
> ^                          anchor the match at the beginning of the line
>
> \\([ ]*[>+\\.][ ]?\\)+     match any number of spaces followed by one of
>                            the three characters >, + or . (a literal
>                            period) followed by 0 or 1 space. If there is
>                            a match, remember what is matched as group 1
>                            (that's what the escaped parentheses
>                            \\(...\\) do). Match one or more of these
>                            (that's what the + at the end does).
>
> \\([[0-9]+\\|[ ]\\)        match either an emtpy space or a sequence
>                            of one or more of the characters [ or 0-9
>                            i.e. an opening square bracket or a digit.
>                            remember what is matched as group 2.
>
> The latter will match [0[1[2[3 e.g. which does not sound right.
>
> The best way to find out what a regexp will match is to start with
> a buffer containing example strings that you are trying to match
> and example string that you are trying *not* to match, then invoke
>
>     M-x regexp-builder
>
> and paste the regexp inside the empty set of quotes, then check the highligted
> matches to see if they agree with your expectations.
>
> Footnotes:
>
> [fn:1] Crossing fingers and toes, hoping I've got it right...

Bah, got it wrong: backslash is not special within a character class, so

[>+\\.]

matches > or + or \ or . (a period - which is also not special in a
character class).

I'm not sure what the regexp is supposed to match, but I'm almost sure
that it is wrong :-)

-- 
Nick