I need to have Sphinx index some characters that are apparently part of the internal char_set, notably "," and "&".
As far as I understand there is no way (?!) to simply add these as indexable chars, I need to
Make a char_set table in my index
Not only include the "," and "&" as indexable characters but now manually add the char_set Sphinx uses
This is a little frustrating as it seems one should be able to add back in chars without manually recreating the char_set used internally. However if that is the situation that is the situation, yet in the documentation
http://sphinxsearch.com/docs/current/conf-charset-table.html
I don't see or understand how I would manually specify a char_set table and exclude / index the two or three characters I want.
You do need to duplicate the 'stock' charset_table before you can add to it.
At less than 100 characters, even if you typed it rather than copy/pasting, would still be les effort than typing this whole question!
(even less if use the the english shorthand)
Just copy what there and add your new chars to the end. If you don't know the unicode mapping, something like asciitable.com is useful at least for the chars in ASCII.
Related
I'm trying to come up with a regex for enforcing Git commit messages to match a certain format. I've been banging my head against the keyboard modifying the semi-working version I have, but I just can't get it to work exactly as I want. Here's what I have now:
/^([a-z]{2,4}-[\d]{2,5}[, \n]{1,2})+\n{1}^[\w\n\s\*\-\.\:\'\,]+/i
Here's the text I'm trying to enforce:
AB-1432, ABC-435, ABCD-42
Here is the multiline description, following a blank
line after the Jira issue IDs
- Maybe bullet points, with either dashes
* Or asterisks
Currently, it matches that, but it will also match if there's no blank line after the issue IDs, and if there's multiple blank lines after.
Is there anyway to enforce that, or will I just have to live with it?
It's also pretty ugly, I'm sure there's a more succinct way to write that out.
Thanks.
Your regex allows for \n as one of the possible characters after the required newline, so that's why it matches when there are multiple.
Here's a cleaned up regex:
/^([a-z]{2,4}-\d{2,5}(?=[, \n]),? ?\n?)+^\n([-\w\s*.:',]+\n)+/i
Notes:
This requires at least one [-\w\s*.:',] character before the next newline.
I changed the issue IDs to have one possible comma, space, and newline, in that order (up to one of each). Can you use lookaheads? If so, I added (?=[, \n]) to make sure the issue ID is followed by at least one of those characters.
Also notice that many of the characters don't need to be escaped in a character class.
I have been looking at regular expressions to try and do this, but the most I can do is find the start of a line with ^, but not replace it.
I can then find the first characters on a line to replace, but can not do it in such a way with keeping it intact.
Unfortunately I don´t have access to a tool like cut since I am on a windows machine...so is there any way to do what I want with just regexp?
Use notepad++. It offers a way to record an sequence of actions which then can be repeated for all lines in the file.
Did you try replacing the regular expression ^ with the text you want to put at the start of each line? Also you should use the multiline option (also called m in some regex dialects) if you want ^ to match the start of every line in your input rather than just the first.
string s = "test test\ntest2 test2";
s = Regex.Replace(s, "^", "foo", RegexOptions.Multiline);
Console.WriteLine(s);
Result:
footest test
footest2 test2
I used to program on the mainframe and got used to SPF panels. I was thrilled to find a Windows version of the same editor at Command Technology. Makes problems like this drop-dead simple. You can use expressions to exclude or include lines, then apply transforms on just the excluded or included lines and do so inside of column boundaries. You can even take the contents of one set of lines and overlay the contents of another set of lines entirely or within column boundaries which makes it very easy to generate mass assignments of values to variables and similar tasks. I use Notepad++ for most stuff but keep a copy of SPFSE around for special-purpose editing like this. It's not cheap but once you figure out how to use it, it pays for itself in time saved.
In my sphinx config file, I have the following:
ignore_chars: "U+0027"
charset_table: "0..9, a..z, _, A..Z->a..z, U+00C0->a, U+00C1->a,
U+00C2->a, U+00C3->a, U+00C4->a, U+00C5->a, U+00C7->c, U+00C8->e,
U+00C9->e, U+00CA->e, U+00CB->e, U+00CC->i, U+00CD->i, U+00CE->i [SNIP]"
(The charset_table entry is from here: http://speeple.com/unicode-maps.txt)
The expected result is that querying kyles will return all records matching kyles and/or kyle's, since I'm telling sphinx to exclude ' (single quote/apos) from the index (ab'cd -> abcd). However, in practice, this is not happening.
I believe adding it to the ignore_chars has the opposite of the desired effect. This is telling sphinx not to split on that character, but instead it will collapse the word around the characters to be ignored. So, kyle's will become kyles instead of kyle and s.
The solution I just tried for this issue that seems to have worked was to add s to my list of stopwords (might need 's in there also, can't remember). Sphinx seems to split kyle's up into the words kyle and 's. Because match all mode is on, some documents fail on the match for 's. Adding it to the stop words seems to have the desired effect.
It seems like the normal stemming should take care of this however, so maybe we're both doing something wrong...
For coding reasons which would horrify you (I'm too embarrassed to say), I need to store a number of text items in a single string.
I will delimit them using a character.
Which character is best to use for this, i.e. which character is the least likely to appear in the text? Must be printable and probably less than 128 in ASCII to avoid locale issues.
I would choose "Unit Separator" ASCII code "US": ASCII 31 (0x1F)
In the old, old days, most things were done serially, without random access. This meant that a few control codes were embedded into ASCII.
ASCII 28 (0x1C) File Separator - Used to indicate separation between files on a data input stream.
ASCII 29 (0x1D) Group Separator - Used to indicate separation between tables on a data input stream (called groups back then).
ASCII 30 (0x1E) Record Separator - Used to indicate separation between records within a table (within a group). These roughly map to a tuple in modern nomenclature.
ASCII 31 (0x1F) Unit Separator - Used to indicate separation between units within a record. The roughly map to fields in modern nomenclature.
Unit Separator is in ASCII, and there is Unicode support for displaying it (typically a "us" in the same glyph) but many fonts don't display it.
If you must display it, I would recommend displaying it in-application, after it was parsed into fields.
Assuming for some embarrassing reason you can't use CSV I'd say go with the data. Take some sample data, and do a simple character count for each value 0-127. Choose one of the ones which doesn't occur. If there is too much choice get a bigger data set. It won't take much time to write, and you'll get the answer best for you.
The answer will be different for different problem domains, so | (pipe) is common in shell scripts, ^ is common in math formulae, and the same is probably true for most other characters.
I personally think I'd go for | (pipe) if given a choice but going with real data is safest.
And whatever you do, make sure you've worked out an escaping scheme!
When using different languages, this symbol: ¬
proved to be the best. However I'm still testing.
Probably | or ^ or ~ you could also combine two characters
You said "printable", but that can include characters such as a tab (0x09) or form feed (0x0c). I almost always choose tabs rather than commas for delimited files, since commas can sometimes appear in text.
(Interestingly enough the ascii table has characters GS (0x1D), RS (0x1E), and US (0x1F) for group, record, and unit separators, whatever those are/were.)
If by "printable" you mean a character that a user could recognize and easily type in, I would go for the pipe | symbol first, with a few other weird characters (# or ~ or ^ or \, or backtick which I can't seem to enter here) as a possibility. These characters +=!$%&*()-'":;<>,.?/ seem like they would be more likely to occur in user input. As for underscore _ and hash # and the brackets {}[] I don't know.
How about you use a CSV style format? Characters can be escaped in a standard CSV format, and there's already a lot of parsers already written.
Can you use a pipe symbol? That's usually the next most common delimiter after comma or tab delimited strings. It's unlikely most text would contain a pipe, and ord('|') returns 124 for me, so that seems to fit your requirements.
For fast escaping I use stuff like this:
say you want to concatinate str1, str2 and str3
what I do is:
delimitedStr=str1.Replace("#","#a").Replace("|","#p")+"|"+str2.Replace("#","#a").Replace("|","#p")+"|"+str3.Replace("#","#a").Replace("|","#p");
then to retrieve original use:
splitStr=delimitedStr.Split("|".ToCharArray());
str1=splitStr[0].Replace("#p","|").Replace("#a","#");
str2=splitStr[1].Replace("#p","|").Replace("#a","#");
str3=splitStr[2].Replace("#p","|").Replace("#a","#");
note: the order of the replace is important
its unbreakable and easy to implement
Pipe for the win! |
We use ascii 0x7f which is pseudo-printable and hardly ever comes up in regular usage.
Well it's going to depend on the nature of your text to some extent but a vertical bar 0x7C doesn't crop up in text very often.
I don't think I've ever seen an ampersand followed by a comma in natural text, but you can check the file first to see if it contains the delimiter, and if so, use an alternative. If you want to always be able to know that the delimiter you use will not cause a conflict, then do a loop checking the file for the delimiter you want, and if it exists, then double the string until the file no longer has a match. It doesn't matter if there are similar strings because your program will only look for exact delimiter matches.
This can be good or bad (usually bad) depending on the situation and language, but keep mind mind that you can always Base64 encode the whole thing. You then don't have to worry about escaping and unescaping various patterns on each side, and you can simply seperate and split strings based on a character which isn't used in your Base64 charset.
I have had to resort to this solution when faced with putting XML documents into XML properties/nodes. Properties can't have CDATA blocks in them at all, and nodes escaped as CDATA obviously cannot have further CDATA blocks inside that without breaking the structure.
CSV is probably a better idea for most situations, though.
Both pipe and caret are the obvious choices. I would note that if users are expected to type the entire response, caret is easier to find on any keyboard than is pipe.
I've used double pipe and double caret before. The idea of a non printable char works if your not hand creating or modifying the file. For quick random access file storage and retrieval field width is used. You don't even have to read the file.. your literally pulling from the file by reference. This is how databases do some storage.. but they also manage the spaces between records and such. And it introduced the problem of max data element width. (Index attach a header which is used to define the width of each element and it's data type in the original old days.. later they introduced compression with remapping chars. This allows for a text file to get about 1/8 the size in transmission.. variable length char encoding for the win
make it dynamic : )
announce your control characters in the file header
for example
delimiter: ~
escape: \
wrapline: $
width: 19
hello world~this i$
s \\just\\ a sampl$
e text~$someVar$~h$
ere is some \~\~ma$
rkdown strikethrou$
gh\~\~ text
would give the strings
hello world
this is \just\ a sample text
$someVar$
here is some ~~markdown strikethrough~~ text
i have implemented something similar:
a plaintar text container format,
to escape and wrap utf16 text in ascii,
as an alternative to mime multipart messages.
see https://github.com/milahu/live-diff-html-editor
I need to parse some text from pdfs but the pdf formatting results in extremely unreliable spacing. The result is that I have to ignore the spaces and have a continuous stream of non-space characters.
Any suggestions on how to parse the string and put spaces back into the string by guessing?
I'm using ruby. Or should I say I'musingruby?
Edit: I've pulled the text out using pdf-reader. Some of the pdf files are nicely formatted and some are not. An example of text mixed with positioning:
.7aspe-5.5cts-715.1o0.6f-708.5f-0.4aces-721.4that-716.3are-720.0i-1.8mportant-716.3in-713.9soc-5.5i-1.8alcommunica6.6tion6.3.-711.6Althoug6.3h-708.1m-1.9od6.3els-709.3o6.4f-702.8f5.4ace-707.9proc6.6essing-708.2haveproposed-611.2ways-615.5to-614.7deal-613.2with-613.0these-613.9diff10.4erent-613.7tasks,-611.9it-617.1remainsunclear-448.0how-450.7these-443.2mechanisms-451.7might-446.7be-447.7implemented-447.2in-450.3visualOne-418.9model-418.8of-417.3human-416.4face-421.9processing-417.5proposes-422.7that-419.8informa-tion-584.5is-578.0processed-586.1in-583.1specialised-584.7modules-577.0(Breen-584.4et-582.9al.,-582.32002;Bruce-382.1and-384.0Y92.0oung,-380.21986;-379.2Haxby-379.9et-380.5al.,-
and if I print just string data (I added returns at the end of each line to keep it from
messing up the layout here:
'Distinctrepresentationsforfacialidentityandchangeableaspectsoffacesinthehumantemporal
lobeTimothyJ.Andrews*andMichaelP.EwbankDepartmentofPsychology,WolfsonResearchInstitute,
UniversityofDurham,UKReceived23December2003;revised26March2004;accepted27July2004Availab
leonline14October2004Theneuralsystemunderlyingfaceperceptionmustrepresenttheunchanging
featuresofafacethatspecifyidentity,aswellasthechangeableaspectsofafacethatfacilitates
ocialcommunication.However,thewayinformationaboutfacesisrepresentedinthebrainremainsc
ontroversial.Inthisstudy,weusedfMRadaptation(thereductioninfMRIactivitythatfollowsthe
repeatedpresentationofidenticalimages)toaskhowdifferentface-andobject-selectiveregionsofvisualcortexcontributetospecificaspectsoffaceperception'
The data is spit out by callbacks so if I print each string as it is returned it looks like this:
'The
-571.3
neural
-573.7
system
-577.4
underly
13.9
ing
-577.2
face
-573.0
perc
13.7
eption
-574.9
must
-572.1
repr
20.8
esent
-577.0
the
unchangin
14.4
g
-538.5
featur
16.5
es
-529.5
of
-536.6
a
-531.4
face
'
On examination it looks like the true spaces are large negative numbers < -300 and the false spaces are much smaller positive numbers. Thanks guys. Just getting to the point where i am asking the question clearly helped me answer it!
Hmmmm... I'd have to say that guessing is never a good idea. Looking at the problem root cause and solving that is the answer, anything else is a kludge.
If the spacing is unreliable from the PDF, how is it unreliable? The PDF viewer needs to be able to reliably space the text so the data is there somewhere, you just need to find it.
EDIT following comment:
The idea of parsing the file using a dictionary (your only other option really, apart from randomly inserting spaces and hoping for the best) and inserting spaces at identified word boundaries (a real problem when dealing with punctuation, plurals that don't alter the base word i.e. plural, etc) would, I believe, be a much greater programming challenge than correctly parsing the PDF in the first place. After all, PDF is clearly defined whereas English is somewhat wooly.
Why not look down the route of existing solutions like ps2ascii in linux, call the function from your Ruby and pick up the result.
PDF doesn't only store spaces as space characters, but also uses layout commands for spacing (so it doesn't print a space, but moves the "pen" to the right). Perhaps you should have a look at the PDF reference (the big PDF on the bottom of the site), Chapter 9 "Text" should be what you're looking for.
EDIT: After reading your comment to Lazarus' answer, this doesn't seem to be what you're looking for. I think you should try to get a word list from somewhere and try to split your text using it. A good strategy would be to do that using recursion, because for example:
"meandyou"
The first word could be "me" or "mean", but if you try "mean", "dyou" doesn't make sense, so it will be "me", same for the next word that could be "a" or "an" or "and", only "and" makes sense.
If it were me I'd go back to the source PDFs and try a different method of extracting the text, such as iText (for Java) or maybe some kind of PDF-to-HTML to text conversion software method.