Locale::Maketext:Perl1Programmers RefeLocale::Maketext::TPJ13(3p)NAMELocale::Maketext::TPJ13-- article about software localiza-
tion
SYNOPSIS
# This an article, not a module.
DESCRIPTION
The following article by Sean M. Burke and Jordan Lachler
first appeared in The Perl Journal #13 and is copyright 1999
The Perl Journal. It appears courtesy of Jon Orwant and The
Perl Journal. This document may be distributed under the
same terms as Perl itself.
Localization and Perl: gettext breaks, Maketext fixes
by Sean M. Burke and Jordan Lachler
This article points out cases where gettext (a common system
for localizing software interfaces -- i.e., making them work
in the user's language of choice) fails because of basic
differences between human languages. This article then
describes Maketext, a new system capable of correctly treat-
ing these differences.
A Localization Horror Story: It Could Happen To You
"There are a number of languages spoken by human beings
in this world."
-- Harald Tveit Alvestrand, in RFC 1766, "Tags for the
Identification of Languages"
Imagine that your task for the day is to localize a piece of
software -- and luckily for you, the only output the program
emits is two messages, like this:
I scanned 12 directories.
Your query matched 10 files in 4 directories.
So how hard could that be? You look at the code that pro-
duces the first item, and it reads:
printf("I scanned %g directories.",
$directory_count);
You think about that, and realize that it doesn't even work
right for English, as it can produce this output:
I scanned 1 directories.
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So you rewrite it to read:
printf("I scanned %g %s.",
$directory_count,
$directory_count == 1 ?
"directory" : "directories",
);
...which does the Right Thing. (In case you don't recall,
"%g" is for locale-specific number interpolation, and "%s"
is for string interpolation.)
But you still have to localize it for all the languages
you're producing this software for, so you pull
Locale::gettext off of CPAN so you can access the "gettext"
C functions you've heard are standard for localization
tasks.
And you write:
printf(gettext("I scanned %g %s."),
$dir_scan_count,
$dir_scan_count == 1 ?
gettext("directory") : gettext("directories"),
);
But you then read in the gettext manual (Drepper, Miller,
and Pinard 1995) that this is not a good idea, since how a
single word like "directory" or "directories" is translated
may depend on context -- and this is true, since in a case
language like German or Russian, you'd may need these words
with a different case ending in the first instance (where
the word is the object of a verb) than in the second
instance, which you haven't even gotten to yet (where the
word is the object of a preposition, "in %g directories") --
assuming these keep the same syntax when translated into
those languages.
So, on the advice of the gettext manual, you rewrite:
printf( $dir_scan_count == 1 ?
gettext("I scanned %g directory.") :
gettext("I scanned %g directories."),
$dir_scan_count );
So, you email your various translators (the boss decides
that the languages du jour are Chinese, Arabic, Russian, and
Italian, so you have one translator for each), asking for
translations for "I scanned %g directory." and "I scanned %g
directories.". When they reply, you'll put that in the lex-
icons for gettext to use when it localizes your software, so
that when the user is running under the "zh" (Chinese)
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locale, gettext("I scanned %g directory.") will return the
appropriate Chinese text, with a "%g" in there where printf
can then interpolate $dir_scan.
Your Chinese translator emails right back -- he says both of
these phrases translate to the same thing in Chinese,
because, in linguistic jargon, Chinese "doesn't have number
as a grammatical category" -- whereas English does. That
is, English has grammatical rules that refer to "number",
i.e., whether something is grammatically singular or plural;
and one of these rules is the one that forces nouns to take
a plural suffix (generally "s") when in a plural context, as
they are when they follow a number other than "one" (includ-
ing, oddly enough, "zero"). Chinese has no such rules, and
so has just the one phrase where English has two. But, no
problem, you can have this one Chinese phrase appear as the
translation for the two English phrases in the "zh" gettext
lexicon for your program.
Emboldened by this, you dive into the second phrase that
your software needs to output: "Your query matched 10 files
in 4 directories.". You notice that if you want to treat
phrases as indivisible, as the gettext manual wisely
advises, you need four cases now, instead of two, to cover
the permutations of singular and plural on the two items,
$dir_count and $file_count. So you try this:
printf( $file_count == 1 ?
( $directory_count == 1 ?
gettext("Your query matched %g file in %g directory.") :
gettext("Your query matched %g file in %g directories.") ) :
( $directory_count == 1 ?
gettext("Your query matched %g files in %g directory.") :
gettext("Your query matched %g files in %g directories.") ),
$file_count, $directory_count,
);
(The case of "1 file in 2 [or more] directories" could, I
suppose, occur in the case of symlinking or something of the
sort.)
It occurs to you that this is not the prettiest code you've
ever written, but this seems the way to go. You mail off to
the translators asking for translations for these four
cases. The Chinese guy replies with the one phrase that
these all translate to in Chinese, and that phrase has two
"%g"s in it, as it should -- but there's a problem. He
translates it word-for-word back: "In %g directories con-
tains %g files match your query." The %g slots are in an
order reverse to what they are in English. You wonder how
you'll get gettext to handle that.
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But you put it aside for the moment, and optimistically hope
that the other translators won't have this problem, and that
their languages will be better behaved -- i.e., that they
will be just like English.
But the Arabic translator is the next to write back. First
off, your code for "I scanned %g directory." or "I scanned
%g directories." assumes there's only singular or plural.
But, to use linguistic jargon again, Arabic has grammatical
number, like English (but unlike Chinese), but it's a
three-term category: singular, dual, and plural. In other
words, the way you say "directory" depends on whether
there's one directory, or two of them, or more than two of
them. Your test of "($directory == 1)" no longer does the
job. And it means that where English's grammatical category
of number necessitates only the two permutations of the
first sentence based on "directory [singular]" and "direc-
tories [plural]", Arabic has three -- and, worse, in the
second sentence ("Your query matched %g file in %g direc-
tory."), where English has four, Arabic has nine. You sense
an unwelcome, exponential trend taking shape.
Your Italian translator emails you back and says that "I
searched 0 directories" (a possible English output of your
program) is stilted, and if you think that's fine English,
that's your problem, but that just will not do in the
language of Dante. He insists that where $directory_count
is 0, your program should produce the Italian text for "I
didn't scan any directories.". And ditto for "I didn't
match any files in any directories", although he says the
last part about "in any directories" should probably just be
left off.
You wonder how you'll get gettext to handle this; to accomo-
date the ways Arabic, Chinese, and Italian deal with numbers
in just these few very simple phrases, you need to write
code that will ask gettext for different queries depending
on whether the numerical values in question are 1, 2, more
than 2, or in some cases 0, and you still haven't figured
out the problem with the different word order in Chinese.
Then your Russian translator calls on the phone, to person-
ally tell you the bad news about how really unpleasant your
life is about to become:
Russian, like German or Latin, is an inflectional language;
that is, nouns and adjectives have to take endings that
depend on their case (i.e., nominative, accusative, geni-
tive, etc...) -- which is roughly a matter of what role they
have in syntax of the sentence -- as well as on the grammat-
ical gender (i.e., masculine, feminine, neuter) and number
(i.e., singular or plural) of the noun, as well as on the
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declension class of the noun. But unlike with most other
inflected languages, putting a number-phrase (like "ten" or
"forty-three", or their Arabic numeral equivalents) in front
of noun in Russian can change the case and number that noun
is, and therefore the endings you have to put on it.
He elaborates: In "I scanned %g directories", you'd expect
"directories" to be in the accusative case (since it is the
direct object in the sentnce) and the plural number, except
where $directory_count is 1, then you'd expect the singular,
of course. Just like Latin or German. But! Where
$directory_count % 10 is 1 ("%" for modulo, remember),
assuming $directory count is an integer, and except where
$directory_count % 100 is 11, "directories" is forced to
become grammatically singular, which means it gets the end-
ing for the accusative singular... You begin to visualize
the code it'd take to test for the problem so far, and still
work for Chinese and Arabic and Italian, and how many get-
text items that'd take, but he keeps going... But where
$directory_count % 10 is 2, 3, or 4 (except where
$directory_count % 100 is 12, 13, or 14), the word for
"directories" is forced to be genitive singular -- which
means another ending... The room begins to spin around you,
slowly at first... But with all other integer values, since
"directory" is an inanimate noun, when preceded by a number
and in the nominative or accusative cases (as it is here,
just your luck!), it does stay plural, but it is forced into
the genitive case -- yet another ending... And you never
hear him get to the part about how you're going to run into
similar (but maybe subtly different) problems with other
Slavic languages like Polish, because the floor comes up to
meet you, and you fade into unconsciousness.
The above cautionary tale relates how an attempt at locali-
zation can lead from programmer consternation, to program
obfuscation, to a need for sedation. But careful evaluation
shows that your choice of tools merely needed further con-
sideration.
The Linguistic View
"It is more complicated than you think."
-- The Eighth Networking Truth, from RFC 1925
The field of Linguistics has expended a great deal of effort
over the past century trying to find grammatical patterns
which hold across languages; it's been a constant process of
people making generalizations that should apply to all
languages, only to find out that, all too often, these gen-
eralizations fail -- sometimes failing for just a few
languages, sometimes whole classes of languages, and
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sometimes nearly every language in the world except English.
Broad statistical trends are evident in what the "average
language" is like as far as what its rules can look like,
must look like, and cannot look like. But the "average
language" is just as unreal a concept as the "average per-
son" -- it runs up against the fact no language (or person)
is, in fact, average. The wisdom of past experience leads
us to believe that any given language can do whatever it
wants, in any order, with appeal to any kind of grammatical
categories wants -- case, number, tense, real or metaphoric
characteristics of the things that words refer to, arbitrary
or predictable classifications of words based on what end-
ings or prefixes they can take, degree or means of certainty
about the truth of statements expressed, and so on, ad
infinitum.
Mercifully, most localization tasks are a matter of finding
ways to translate whole phrases, generally sentences, where
the context is relatively set, and where the only variation
in content is usually in a number being expressed -- as in
the example sentences above. Translating specific, fully-
formed sentences is, in practice, fairly foolproof -- which
is good, because that's what's in the phrasebooks that so
many tourists rely on. Now, a given phrase (whether in a
phrasebook or in a gettext lexicon) in one language might
have a greater or lesser applicability than that phrase's
translation into another language -- for example, strictly
speaking, in Arabic, the "your" in "Your query matched..."
would take a different form depending on whether the user is
male or female; so the Arabic translation "your[feminine]
query" is applicable in fewer cases than the corresponding
English phrase, which doesn't distinguish the user's gender.
(In practice, it's not feasable to have a program know the
user's gender, so the masculine "you" in Arabic is usually
used, by default.)
But in general, such surprises are rare when entire sen-
tences are being translated, especially when the functional
context is restricted to that of a computer interacting with
a user either to convey a fact or to prompt for a piece of
information. So, for purposes of localization, translation
by phrase (generally by sentence) is both the simplest and
the least problematic.
Breaking gettext
"It Has To Work."
-- First Networking Truth, RFC 1925
Consider that sentences in a tourist phrasebook are of two
types: ones like "How do I get to the marketplace?" that
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don't have any blanks to fill in, and ones like "How much do
these ___ cost?", where there's one or more blanks to fill
in (and these are usually linked to a list of words that you
can put in that blank: "fish", "potatoes", "tomatoes", etc.)
The ones with no blanks are no problem, but the fill-in-
the-blank ones may not be really straightforward. If it's a
Swahili phrasebook, for example, the authors probably didn't
bother to tell you the complicated ways that the verb "cost"
changes its inflectional prefix depending on the noun you're
putting in the blank. The trader in the marketplace will
still understand what you're saying if you say "how much do
these potatoes cost?" with the wrong inflectional prefix on
"cost". After all, you can't speak proper Swahili, you're
just a tourist. But while tourists can be stupid, computers
are supposed to be smart; the computer should be able to
fill in the blank, and still have the results be grammati-
cal.
In other words, a phrasebook entry takes some values as
parameters (the things that you fill in the blank or
blanks), and provides a value based on these parameters,
where the way you get that final value from the given values
can, properly speaking, involve an arbitrarily complex
series of operations. (In the case of Chinese, it'd be not
at all complex, at least in cases like the examples at the
beginning of this article; whereas in the case of Russian
it'd be a rather complex series of operations. And in some
languages, the complexity could be spread around dif-
ferently: while the act of putting a number-expression in
front of a noun phrase might not be complex by itself, it
may change how you have to, for example, inflect a verb
elsewhere in the sentence. This is what in syntax is called
"long-distance dependencies".)
This talk of parameters and arbitrary complexity is just
another way to say that an entry in a phrasebook is what in
a programming language would be called a "function". Just
so you don't miss it, this is the crux of this article: A
phrase is a function; a phrasebook is a bunch of functions.
The reason that using gettext runs into walls (as in the
above second-person horror story) is that you're trying to
use a string (or worse, a choice among a bunch of strings)
to do what you really need a function for -- which is
futile. Preforming (s)printf interpolation on the strings
which you get back from gettext does allow you to do some
common things passably well... sometimes... sort of; but, to
paraphrase what some people say about "csh" script program-
ming, "it fools you into thinking you can use it for real
things, but you can't, and you don't discover this until
you've already spent too much time trying, and by then it's
too late."
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Replacing gettext
So, what needs to replace gettext is a system that supports
lexicons of functions instead of lexicons of strings. An
entry in a lexicon from such a system should not look like
this:
"J'ai trouv\xE9 %g fichiers dans %g r\xE9pertoires"
[\xE9 is e-acute in Latin-1. Some pod renderers would
scream if I used the actual character here. -- SB]
but instead like this, bearing in mind that this is just a
first stab:
sub I_found_X1_files_in_X2_directories {
my( $files, $dirs ) = @_[0,1];
$files = sprintf("%g %s", $files,
$files == 1 ? 'fichier' : 'fichiers');
$dirs = sprintf("%g %s", $dirs,
$dirs == 1 ? "r\xE9pertoire" : "r\xE9pertoires");
return "J'ai trouv\xE9 $files dans $dirs.";
}
Now, there's no particularly obvious way to store anything
but strings in a gettext lexicon; so it looks like we just
have to start over and make something better, from scratch.
I call my shot at a gettext-replacement system "Maketext",
or, in CPAN terms, Locale::Maketext.
When designing Maketext, I chose to plan its main features
in terms of "buzzword compliance". And here are the buzz-
words:
Buzzwords: Abstraction and Encapsulation
The complexity of the language you're trying to output a
phrase in is entirely abstracted inside (and encapsulated
within) the Maketext module for that interface. When you
call:
print $lang->maketext("You have [quant,_1,piece] of new mail.",
scalar(@messages));
you don't know (and in fact can't easily find out) whether
this will involve lots of figuring, as in Russian (if $lang
is a handle to the Russian module), or relatively little, as
in Chinese. That kind of abstraction and encapsulation may
encourage other pleasant buzzwords like modularization and
stratification, depending on what design decisions you make.
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Buzzword: Isomorphism
"Isomorphism" means "having the same structure or form"; in
discussions of program design, the word takes on the spe-
cial, specific meaning that your implementation of a solu-
tion to a problem has the same structure as, say, an infor-
mal verbal description of the solution, or maybe of the
problem itself. Isomorphism is, all things considered, a
good thing -- it's what problem-solving (and
solution-implementing) should look like.
What's wrong the with gettext-using code like this...
printf( $file_count == 1 ?
( $directory_count == 1 ?
"Your query matched %g file in %g directory." :
"Your query matched %g file in %g directories." ) :
( $directory_count == 1 ?
"Your query matched %g files in %g directory." :
"Your query matched %g files in %g directories." ),
$file_count, $directory_count,
);
is first off that it's not well abstracted -- these ways of
testing for grammatical number (as in the expressions like
"foo == 1 ? singular_form : plural_form") should be
abstracted to each language module, since how you get gram-
matical number is language-specific.
But second off, it's not isomorphic -- the "solution" (i.e.,
the phrasebook entries) for Chinese maps from these four
English phrases to the one Chinese phrase that fits for all
of them. In other words, the informal solution would be
"The way to say what you want in Chinese is with the one
phrase 'For your question, in Y directories you would find X
files'" -- and so the implemented solution should be, iso-
morphically, just a straightforward way to spit out that one
phrase, with numerals properly interpolated. It shouldn't
have to map from the complexity of other languages to the
simplicity of this one.
Buzzword: Inheritance
There's a great deal of reuse possible for sharing of
phrases between modules for related dialects, or for sharing
of auxiliary functions between related languages. (By "aux-
iliary functions", I mean functions that don't produce
phrase-text, but which, say, return an answer to "does this
number require a plural noun after it?". Such auxiliary
functions would be used in the internal logic of functions
that actually do produce phrase-text.)
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In the case of sharing phrases, consider that you have an
interface already localized for American English (probably
by having been written with that as the native locale, but
that's incidental). Localizing it for UK English should, in
practical terms, be just a matter of running it past a Brit-
ish person with the instructions to indicate what few
phrases would benefit from a change in spelling or possibly
minor rewording. In that case, you should be able to put in
the UK English localization module only those phrases that
are UK-specific, and for all the rest, inherit from the
American English module. (And I expect this same situation
would apply with Brazilian and Continental Portugese, poss-
bily with some very closely related languages like Czech and
Slovak, and possibly with the slightly different "versions"
of written Mandarin Chinese, as I hear exist in Taiwan and
mainland China.)
As to sharing of auxiliary functions, consider the problem
of Russian numbers from the beginning of this article; obvi-
ously, you'd want to write only once the hairy code that,
given a numeric value, would return some specification of
which case and number a given quanitified noun should use.
But suppose that you discover, while localizing an interface
for, say, Ukranian (a Slavic language related to Russian,
spoken by several million people, many of whom would be
relieved to find that your Web site's or software's inter-
face is available in their language), that the rules in
Ukranian are the same as in Russian for quantification, and
probably for many other grammatical functions. While there
may well be no phrases in common between Russian and
Ukranian, you could still choose to have the Ukranian module
inherit from the Russian module, just for the sake of inher-
iting all the various grammatical methods. Or, probably
better organizationally, you could move those functions to a
module called "_E_Slavic" or something, which Russian and
Ukranian could inherit useful functions from, but which
would (presumably) provide no lexicon.
Buzzword: Concision
Okay, concision isn't a buzzword. But it should be, so I
decree that as a new buzzword, "concision" means that simple
common things should be expressible in very few lines (or
maybe even just a few characters) of code -- call it a spe-
cial case of "making simple things easy and hard things pos-
sible", and see also the role it played in the MIDI::Simple
language, discussed elsewhere in this issue [TPJ#13].
Consider our first stab at an entry in our "phrasebook of
functions":
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sub I_found_X1_files_in_X2_directories {
my( $files, $dirs ) = @_[0,1];
$files = sprintf("%g %s", $files,
$files == 1 ? 'fichier' : 'fichiers');
$dirs = sprintf("%g %s", $dirs,
$dirs == 1 ? "r\xE9pertoire" : "r\xE9pertoires");
return "J'ai trouv\xE9 $files dans $dirs.";
}
You may sense that a lexicon (to use a non-committal catch-
all term for a collection of things you know how to say,
regardless of whether they're phrases or words) consisting
of functions expressed as above would make for rather long-
winded and repetitive code -- even if you wisely rewrote
this to have quantification (as we call adding a number
expression to a noun phrase) be a function called like:
sub I_found_X1_files_in_X2_directories {
my( $files, $dirs ) = @_[0,1];
$files = quant($files, "fichier");
$dirs = quant($dirs, "r\xE9pertoire");
return "J'ai trouv\xE9 $files dans $dirs.";
}
And you may also sense that you do not want to bother your
translators with having to write Perl code -- you'd much
rather that they spend their very costly time on just trans-
lation. And this is to say nothing of the near impossibil-
ity of finding a commercial translator who would know even
simple Perl.
In a first-hack implementation of Maketext, each
language-module's lexicon looked like this:
%Lexicon = (
"I found %g files in %g directories"
=> sub {
my( $files, $dirs ) = @_[0,1];
$files = quant($files, "fichier");
$dirs = quant($dirs, "r\xE9pertoire");
return "J'ai trouv\xE9 $files dans $dirs.";
},
... and so on with other phrase => sub mappings ...
);
but I immediately went looking for some more concise way to
basically denote the same phrase-function -- a way that
would also serve to concisely denote most phrase-functions
in the lexicon for most languages. After much time and even
some actual thought, I decided on this system:
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* Where a value in a %Lexicon hash is a contentful string
instead of an anonymous sub (or, conceivably, a coderef), it
would be interpreted as a sort of shorthand expression of
what the sub does. When accessed for the first time in a
session, it is parsed, turned into Perl code, and then
eval'd into an anonymous sub; then that sub replaces the
original string in that lexicon. (That way, the work of
parsing and evaling the shorthand form for a given phrase is
done no more than once per session.)
* Calls to "maketext" (as Maketext's main function is
called) happen thru a "language session handle", notionally
very much like an IO handle, in that you open one at the
start of the session, and use it for "sending signals" to an
object in order to have it return the text you want.
So, this:
$lang->maketext("You have [quant,_1,piece] of new mail.",
scalar(@messages));
basically means this: look in the lexicon for $lang (which
may inherit from any number of other lexicons), and find the
function that we happen to associate with the string "You
have [quant,_1,piece] of new mail" (which is, and should be,
a functioning "shorthand" for this function in the native
locale -- English in this case). If you find such a func-
tion, call it with $lang as its first parameter (as if it
were a method), and then a copy of scalar(@messages) as its
second, and then return that value. If that function was
found, but was in string shorthand instead of being a fully
specified function, parse it and make it into a function
before calling it the first time.
* The shorthand uses code in brackets to indicate method
calls that should be performed. A full explanation is not
in order here, but a few examples will suffice:
"You have [quant,_1,piece] of new mail."
The above code is shorthand for, and will be interpreted as,
this:
sub {
my $handle = $_[0];
my(@params) = @_;
return join '',
"You have ",
$handle->quant($params[1], 'piece'),
"of new mail.";
}
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where "quant" is the name of a method you're using to quan-
tify the noun "piece" with the number $params[0].
A string with no brackety calls, like this:
"Your search expression was malformed."
is somewhat of a degerate case, and just gets turned into:
sub { return "Your search expression was malformed." }
However, not everything you can write in Perl code can be
written in the above shorthand system -- not by a long shot.
For example, consider the Italian translator from the begin-
ning of this article, who wanted the Italian for "I didn't
find any files" as a special case, instead of "I found 0
files". That couldn't be specified (at least not easily or
simply) in our shorthand system, and it would have to be
written out in full, like this:
sub { # pretend the English strings are in Italian
my($handle, $files, $dirs) = @_[0,1,2];
return "I didn't find any files" unless $files;
return join '',
"I found ",
$handle->quant($files, 'file'),
" in ",
$handle->quant($dirs, 'directory'),
".";
}
Next to a lexicon full of shorthand code, that sort of
sticks out like a sore thumb -- but this is a special case,
after all; and at least it's possible, if not as concise as
usual.
As to how you'd implement the Russian example from the
beginning of the article, well, There's More Than One Way To
Do It, but it could be something like this (using English
words for Russian, just so you know what's going on):
"I [quant,_1,directory,accusative] scanned."
This shifts the burden of complexity off to the quant
method. That method's parameters are: the numeric value
it's going to use to quantify something; the Russian word
it's going to quantify; and the parameter "accusative",
which you're using to mean that this sentence's syntax wants
a noun in the accusative case there, although that quantifi-
cation method may have to overrule, for grammatical reasons
you may recall from the beginning of this article.
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Now, the Russian quant method here is responsible not only
for implementing the strange logic necessary for figuring
out how Russian number-phrases impose case and number on
their noun-phrases, but also for inflecting the Russian word
for "directory". How that inflection is to be carried out
is no small issue, and among the solutions I've seen, some
(like variations on a simple lookup in a hash where all pos-
sible forms are provided for all necessary words) are
straightforward but can become cumbersome when you need to
inflect more than a few dozen words; and other solutions
(like using algorithms to model the inflections, storing
only root forms and irregularities) can involve more over-
head than is justifiable for all but the largest lexicons.
Mercifully, this design decision becomes crucial only in the
hairiest of inflected languages, of which Russian is by no
means the worst case scenario, but is worse than most. Most
languages have simpler inflection systems; for example, in
English or Swahili, there are generally no more than two
possible inflected forms for a given noun ("error/errors";
"kosa/makosa"), and the rules for producing these forms are
fairly simple -- or at least, simple rules can be formulated
that work for most words, and you can then treat the excep-
tions as just "irregular", at least relative to your ad hoc
rules. A simpler inflection system (simpler rules, fewer
forms) means that design decisions are less crucial to main-
taining sanity, whereas the same decisions could incur
overhead-versus-scalability problems in languages like Rus-
sian. It may also be likely that code (possibly in Perl, as
with Lingua::EN::Inflect, for English nouns) has already
been written for the language in question, whether simple or
complex.
Moreover, a third possibility may even be simpler than any-
thing discussed above: "Just require that all possible (or
at least applicable) forms be provided in the call to the
given language's quant method, as in:"
"I found [quant,_1,file,files]."
That way, quant just has to chose which form it needs,
without having to look up or generate anything. While pos-
sibly not optimal for Russian, this should work well for
most other languages, where quantification is not as compli-
cated an operation.
The Devil in the Details
There's plenty more to Maketext than described above -- for
example, there's the details of how language tags ("en-US",
"i-pwn", "fi", etc.) or locale IDs ("en_US") interact with
actual module naming ("BogoQuery/Locale/en_us.pm"), and what
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magic can ensue; there's the details of how to record (and
possibly negotiate) what character encoding Maketext will
return text in (UTF8? Latin-1? KOI8?). There's the
interesting fact that Maketext is for localization, but
nowhere actually has a ""use locale;"" anywhere in it. For
the curious, there's the somewhat frightening details of how
I actually implement something like data inheritance so that
searches across modules' %Lexicon hashes can parallel how
Perl implements method inheritance.
And, most importantly, there's all the practical details of
how to actually go about deriving from Maketext so you can
use it for your interfaces, and the various tools and con-
ventions for starting out and maintaining individual
language modules.
That is all covered in the documentation for
Locale::Maketext and the modules that come with it, avail-
able in CPAN. After having read this article, which covers
the why's of Maketext, the documentation, which covers the
how's of it, should be quite straightfoward.
The Proof in the Pudding: Localizing Web Sites
Maketext and gettext have a notable difference: gettext is
in C, accessible thru C library calls, whereas Maketext is
in Perl, and really can't work without a Perl interpreter
(although I suppose something like it could be written for
C). Accidents of history (and not necessarily lucky ones)
have made C++ the most common language for the implementa-
tion of applications like word processors, Web browsers, and
even many in-house applications like custom query systems.
Current conditions make it somewhat unlikely that the next
one of any of these kinds of applications will be written in
Perl, albeit clearly more for reasons of custom and inertia
than out of consideration of what is the right tool for the
job.
However, other accidents of history have made Perl a well-
accepted language for design of server-side programs (gen-
erally in CGI form) for Web site interfaces. Localization
of static pages in Web sites is trivial, feasable either
with simple language-negotiation features in servers like
Apache, or with some kind of server-side inclusions of
language-appropriate text into layout templates. However, I
think that the localization of Perl-based search systems (or
other kinds of dynamic content) in Web sites, be they public
or access-restricted, is where Maketext will see the
greatest use.
I presume that it would be only the exceptional Web site
that gets localized for English and Chinese and Italian and
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Arabic and Russian, to recall the languages from the begin-
ning of this article -- to say nothing of German, Spanish,
French, Japanese, Finnish, and Hindi, to name a few
languages that benefit from large numbers of programmers or
Web viewers or both.
However, the ever-increasing internationalization of the Web
(whether measured in terms of amount of content, of numbers
of content writers or programmers, or of size of content
audiences) makes it increasingly likely that the interface
to the average Web-based dynamic content service will be
localized for two or maybe three languages. It is my hope
that Maketext will make that task as simple as possible, and
will remove previous barriers to localization for languages
dissimilar to English.
__END__
Sean M. Burke (sburke@cpan.org) has a Master's in linguis-
tics from Northwestern University; he specializes in
language technology. Jordan Lachler (lachler@unm.edu) is a
PhD student in the Department of Linguistics at the Univer-
sity of New Mexico; he specializes in morphology and
pedagogy of North American native languages.
References
Alvestrand, Harald Tveit. 1995. RFC 1766: Tags for the
Identification of Languages.
"ftp://ftp.isi.edu/in-notes/rfc1766.txt" [Now see RFC 3066.]
Callon, Ross, editor. 1996. RFC 1925: The Twelve Network-
ing Truths. "ftp://ftp.isi.edu/in-notes/rfc1925.txt"
Drepper, Ulrich, Peter Miller, and Francois Pinard.
1995-2001. GNU "gettext". Available in
"ftp://prep.ai.mit.edu/pub/gnu/", with extensive docs in the
distribution tarball. [Since I wrote this article in 1998,
I now see that the gettext docs are now trying more to come
to terms with plurality. Whether useful conclusions have
come from it is another question altogether. -- SMB, May
2001]
Forbes, Nevill. 1964. Russian Grammar. Third Edition,
revised by J. C. Dumbreck. Oxford University Press.
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