Re^3: Creating new character classes for foreign languages
by Anonymous Monk on May 17, 2009 at 04:13 UTC
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Not like that, since you must return a specially-formatted string, so like this
sub InThaiVowel {
return join "\n",
'0E30 0E45',
'0E4D',
'0E22',#Thai consonant yo-yak can also be a vowel (like 'y' in English
+)
'0E2D',#Thai consonant or-ang can also be a vowel
'0E27',#Thai consonant wo-wen is only a vowel following mai han-akat
}
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Re^3: Creating new character classes for foreign languages
by graff (Chancellor) on May 17, 2009 at 16:17 UTC
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Is it possible to define a double-character property? For example, the Thai 'r' becomes a vowel if, and only if, there are two of them together, as in 'rr'. It is then pronounced differently, and is no longer strictly an 'r'.
Here you are moving away from strictly orthographic matters into phonetics or phonology, which are essentially context-dependent, and this takes you out of the domain of merely classifying letter symbols into related groups, which is essentially not context-dependent.
If the goal is to provide a means for doing correct word segmentation of Thai text, the handling of the context-dependent rules (like "rr" becomes "un") should probably be in a separate module. The functions that work on sequences of characters will depend on the functions that define the basic character classes.
(You probably could put the subroutines for character-classes and context-dependent rules together in one module if you want to, but the two sets of subroutines will have very different usages from the caller's point of view. And the overall problem being addressed is probably complicated enough that you will want to segregate portions of the solution into separate modules anyway.)
Just curious: have you looked at Lingua::TH::Segmentation? I just happened to notice it was there, but I haven't tried it. Have you? | [reply] |
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Yes, I have looked at that Lingua::TH module. It fails to build on my system, and I have a hard enough time troubleshooting my own code, much less someone else's. The .pm file it has is only 2.2k, which amounts to a very slim algorithm for splitting Thai, as Thai is rather a complex problem when it comes to splitting. I'm actually leaning toward a lexical approach, and working on building a word list in Thai.
In fact, I encountered errors of the wrong number of arguments upon running the 'perl Makefile.PL' command, and commented about five lines in the Makefile.PL before it would run...only to see a warning that the library file referred to was not present. So I'm thinking that it was designed to accompany some additional file, possibly a word lexicon.
This is one of the reasons I'm embarking on this journey now. There is virtually nothing in CPAN for the Thai language, or for Lao either. (And I did some reading on CPAN today, having never submitted anything there before, and learned that a module's NAMESPACE is supposed to be community directed...but I know of no Thai community among Perl monks.)
My needs go beyond splitting syllables. I plan to create a program which will translate Thai to Lao. There are some specific vowels and consonants that must be transposed in the exchange. Syllable splitting is a beginning, but only a part of the process. These tools I am packaging would be useful for many other purposes as well.
Blessings,
~Polyglot~
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So I'm thinking that it was designed to accompany some additional file, possibly a word lexicon.
Yes, that module is clearly intended to serve only as a wrapper around a separate compiled software library (not written in perl), provided here: http://thaiwordseg.sourceforge.net/.
You have to install that library first (which will probably involve a simple sequence like ./configure; make; make install), and then try installing the perl module, which should include some tests that confirm whether the library was found and turns out to work as intended.
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Re^3: Creating new character classes for foreign languages
by JavaFan (Canon) on May 17, 2009 at 10:08 UTC
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Is it possible to define a double-character property?
No.
You are, after all, defining a character class. A character class almost always1 matches exactly one character, never taking context into account.
How might I handle this? Define a rule, not a character class. Out of curiousity, which 'r' in 'rr' is the vowel? First one, second one, or both?
1The only exception I can think of are cases with case insensitive matching, where the Unicode definition defines that the "other case" of a character is a multi character sequence.
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The double 'r' ends up sounding like "un", so I suppose that, technically, the first 'r' becomes the vowel 'u' while the second converts to an 'n'. However, they are considered as a single unit, much like the 'll' or 'ch' have their own places in alphabetical order for Spanish, as if they were single letters.
Now, I've seen that the subroutines in the package file follow a specific syntax...what does a rule look like in a package file?
Also, I had a little trouble when putting my new package to use, in that the "shortcut method" in the final routine here failed, and I ended up hard-coding the code points for those characters.
sub InThaiHCons { #High-class consonants
return <<'END';
0E02 0E03
0E09 0E10
0E16
0E1C 0E1D
0E28 0E29
0E2A 0E2B
END
}
sub InThaiMCons { #Middle-class consonants
return <<'END';
0E01
0E08
0E0E 0E0F
0E14 0E15
0E1A 0E1B
0E2D
END
}
################################ Low-class consonants
=for NON-WORKING EXAMPLE
sub InThaiLCons { #THIS DIDN'T WORK
return <<'END';
+Thai::InThaiCons
-Thai::InThaiHcons
-Thai::InThaiMCons
END
}
=cut
sub InThaiLCons { #THIS DOES WORK
return <<'END';
0E04 0E07
0E0A 0E0D
0E11 0E13
0E17 0E19
0E1E 0E27
0E2C
0E2E
END
}
Why?
Thanks so much for your help!
Blessings,
~Polyglot~ | [reply] [d/l] |
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Regarding the thing that didn't work, did you leave something out from the code that you posted? The "non-working" definition for "InThaiLCons" makes a reference to a sub called "Thai::InThaiCons", but there is no such subroutine in the code you posted. Clearly, referring to a non-existent subroutine will lead to failure.
Based on what you've posted, it looks like you can simply define your three subsets of consonants explicitly (including your definition of "InThaiLCons" that does work), and then create an overall "InThaiCons" sub by adding together the three subsets:
sub InThaiCons {
return <<END;
+Thai::InThaiHcons
+Thai::InThaiMCons
+Thai::InThaiLCons
END
}
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However, they are considered as a single unit, much like the 'll' or 'ch' have their own places in alphabetical order for Spanish, as if they were single letters
This was changed fifteen years ago (probably to make programmers happier). Now, officially, "ch" is sorted between "cg" and "ci" even if it is still considered a single letter and the same applies to "ll" (see http://en.wikipedia.org/wiki/Spanish_language#Writing_system).
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