Locale::Maketext::TPJ13(3p) Perl Programmers Reference Guide #
Locale::Maketext::TPJ13(3p) Perl Programmers Reference Guide
NNAAMMEE #
Locale::Maketext::TPJ13 -- article about software localization
SSYYNNOOPPSSIISS #
# This an article, not a module.
DDEESSCCRRIIPPTTIIOONN #
The following article by Sean M. Burke and Jordan Lachler first appeared
in _T_h_e _P_e_r_l _J_o_u_r_n_a_l #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.
LLooccaalliizzaattiioonn aanndd PPeerrll:: ggeetttteexxtt bbrreeaakkss,, MMaakkeetteexxtt ffiixxeess 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 treating these differences.
AA LLooccaalliizzaattiioonn HHoorrrroorr SSttoorryy:: IItt CCoouulldd HHaappppeenn TToo YYoouu “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 produces 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.
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 lexicons for gettext to use when it localizes your software,
so that when the user is running under the "zh" (Chinese) 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" (including, 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, $directory_count,
);
(The case of "1 file in 2 [or more] directories" could, I suppose, occur
in the case of symlinking or something of the sort.)
It occurs to you that this is not the prettiest code you've ever written,
but this seems the way to go. You mail off to the translators asking for
translations for these four cases. The Chinese guy replies with the one
phrase that these all translate to in Chinese, and that phrase has two
"%g"s in it, as it should -- but there's a problem. He translates it
word-for-word back: "In %g directories contains %g files match your
query." The %g slots are in an order reverse to what they are in
English. You wonder how you'll get gettext to handle that.
But you put it aside for the moment, and optimistically hope that the
other translators won't have this problem, and that their languages will
be better behaved -- i.e., that they will be just like English.
But the Arabic translator is the next to write back. First off, your
code for "I scanned %g directory." or "I scanned %g directories."
assumes there's only singular or plural. But, to use linguistic jargon
again, Arabic has grammatical number, like English (but unlike Chinese),
but it's a three-term category: singular, dual, and plural. In other
words, the way you say "directory" depends on whether there's one
directory, or _t_w_o of them, or _m_o_r_e _t_h_a_n _t_w_o of them. Your test of
"($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
"directories [plural]", Arabic has three -- and, worse, in the second
sentence ("Your query matched %g file in %g directory."), 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 _j_u_s_t _w_i_l_l
_n_o_t _d_o in the language of Dante. He insists that where $directory_count
is 0, your program should produce the Italian text for "I _d_i_d_n_'_t scan _a_n_y
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 accommodate 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 _p_e_r_s_o_n_a_l_l_y 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, genitive, etc...) -- which is roughly a
matter of what role they have in syntax of the sentence -- as well as on
the grammatical gender (i.e., masculine, feminine, neuter) and number
(i.e., singular or plural) of the noun, as well as on the 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 _e_x_p_e_c_t "directories"
to be in the accusative case (since it is the direct object in the
sentence) and the plural number, except where $directory_count is 1, then
you'd expect the singular, of course. Just like Latin or German. _B_u_t_!
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 ending for the accusative singular... You begin to
visualize the code it'd take to test for the problem so far, _a_n_d _s_t_i_l_l
_w_o_r_k _f_o_r _C_h_i_n_e_s_e _a_n_d _A_r_a_b_i_c _a_n_d _I_t_a_l_i_a_n, and how many gettext 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 _a_l_l _o_t_h_e_r 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 localization 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 consideration.
TThhee LLiinngguuiissttiicc VViieeww “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 generalizations fail -- sometimes failing for just a few languages,
sometimes whole classes of languages, and 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 person" -- 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 endings 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 _u_s_u_a_l_l_y 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 _m_i_g_h_t 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 feasible
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 sentences 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.
BBrreeaakkiinngg ggeetttteexxtt “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 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,
_y_o_u can't speak proper Swahili, _y_o_u_'_r_e 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
grammatical.
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 differently: 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 _p_h_r_a_s_e _i_s _a _f_u_n_c_t_i_o_n_; _a _p_h_r_a_s_e_b_o_o_k _i_s _a _b_u_n_c_h _o_f
_f_u_n_c_t_i_o_n_s_.
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 _s_o_m_e common
things passably well... sometimes... sort of; but, to paraphrase what
some people say about "csh" script programming, "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."
RReeppllaacciinngg ggeetttteexxtt 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 _n_o_t 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 buzzwords:
BBuuzzzzwwoorrddss:: AAbbssttrraaccttiioonn aanndd EEnnccaappssuullaattiioonn 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.
BBuuzzzzwwoorrdd:: IIssoommoorrpphhiissmm “Isomorphism” means “having the same structure or form”; in discussions of program design, the word takes on the special, specific meaning that your implementation of a solution to a problem _h_a_s _t_h_e _s_a_m_e _s_t_r_u_c_t_u_r_e as, say, an informal 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 grammatical 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, isomorphically,
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.
BBuuzzzzwwoorrdd:: IInnhheerriittaannccee 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 “auxiliary 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.)
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 British 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 _o_n_l_y those phrases that are UK-specific, and for all the rest,
_i_n_h_e_r_i_t from the American English module. (And I expect this same
situation would apply with Brazilian and Continental Portugese, possibly
with some _v_e_r_y 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; obviously, 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 quantified noun
should use. But suppose that you discover, while localizing an interface
for, say, Ukrainian (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 interface is available in their language), that
the rules in Ukrainian 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 Ukrainian, you could still
choose to have the Ukrainian module inherit from the Russian module, just
for the sake of inheriting 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 Ukrainian could
inherit useful functions from, but which would (presumably) provide no
lexicon.
BBuuzzzzwwoorrdd:: CCoonncciissiioonn 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 special case of “making simple things easy and hard things possible”, 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":
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 _e_x_p_r_e_s_s_e_d 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
_v_e_r_y _c_o_s_t_l_y _t_i_m_e on just translation. And this is to say nothing of the
near impossibility 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 _m_o_s_t phrase-functions in the lexicon for _m_o_s_t languages.
After much time and even some actual thought, I decided on this system:
* 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 function,
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.";
}
where "quant" is the name of a method you're using to quantify the noun
"piece" with the number $params[0].
A string with no brackety calls, like this:
"Your search expression was malformed."
is somewhat of a degenerate case, and just gets turned into:
sub { return "Your search expression was malformed." }
However, not everything you can write in Perl code can be written in the
above shorthand system -- not by a long shot. For example, consider the
Italian translator from the beginning of this article, who wanted the
Italian for "I didn't find any files" as a special case, instead of "I
found 0 files". That couldn't be specified (at least not easily or
simply) in our shorthand system, and it would have to be written out in
full, like this:
sub { # pretend the English strings are in Italian
my($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 _i_s 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 quantification
method may have to overrule, for grammatical reasons you may recall from
the beginning of this article.
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 possible forms
are provided for all necessary words) are straightforward but _c_a_n 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) _c_a_n involve more overhead 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 _w_o_r_s_t 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 exceptions 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
maintaining sanity, whereas the same decisions could incur overhead-
versus-scalability problems in languages like Russian. It may _a_l_s_o 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 anything 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 possibly not optimal for Russian,
this should work well for most other languages, where quantification is
not as complicated an operation.
TThhee DDeevviill iinn tthhee DDeettaaiillss 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 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 conventions 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, available 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 straightforward.
TThhee PPrrooooff iinn tthhee PPuuddddiinngg:: LLooccaalliizziinngg WWeebb SSiitteess 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 implementation 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 (generally in CGI form) for
Web site interfaces. Localization of static pages in Web sites is
trivial, feasible 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 _a_n_d Chinese _a_n_d Italian _a_n_d Arabic _a_n_d Russian, to
recall the languages from the beginning 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 linguistics from
Northwestern University; he specializes in language technology. Jordan
Lachler (lachler@unm.edu) is a PhD student in the Department of
Linguistics at the University of New Mexico; he specializes in morphology
and pedagogy of North American native languages.
RReeffeerreenncceess Alvestrand, Harald Tveit. 1995. _R_F_C _1_7_6_6_: _T_a_g_s _f_o_r _t_h_e _I_d_e_n_t_i_f_i_c_a_t_i_o_n _o_f _L_a_n_g_u_a_g_e_s_. “http://www.ietf.org/rfc/rfc1766.txt” [Now see RFC 3066.]
Callon, Ross, editor. 1996. _R_F_C _1_9_2_5_: _T_h_e _T_w_e_l_v_e _N_e_t_w_o_r_k_i_n_g _T_r_u_t_h_s_.
"<http://www.ietf.org/rfc/rfc1925.txt>"
Drepper, Ulrich, Peter Miller, and François 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. _R_u_s_s_i_a_n _G_r_a_m_m_a_r_. Third Edition, revised by J. C.
Dumbreck. Oxford University Press.
perl v5.36.3 2023-02-15 Locale::Maketext::TPJ13(3p)