


ext::Unicode::NorPerlzProgrext::Unicode::Normalize::Normalize(3p)


NAME
       Unicode::Normalize - Unicode Normalization Forms

SYNOPSIS
       (1) using function names exported by default:

         use Unicode::Normalize;

         $NFD_string  = NFD($string);  # Normalization Form D
         $NFC_string  = NFC($string);  # Normalization Form C
         $NFKD_string = NFKD($string); # Normalization Form KD
         $NFKC_string = NFKC($string); # Normalization Form KC

       (2) using function names exported on request:

         use Unicode::Normalize 'normalize';

         $NFD_string  = normalize('D',  $string);  # Normalization Form D
         $NFC_string  = normalize('C',  $string);  # Normalization Form C
         $NFKD_string = normalize('KD', $string);  # Normalization Form KD
         $NFKC_string = normalize('KC', $string);  # Normalization Form KC

DESCRIPTION
       Parameters:

       $string is used as a string under character semantics (see
       perlunicode).

       $codepoint should be an unsigned integer representing a
       Unicode code point.

       Note: Between XSUB and pure Perl, there is an incompati-
       bility about the interpretation of $codepoint as a decimal
       number.  XSUB converts $codepoint to an unsigned integer,
       but pure Perl does not.  Do not use a floating point nor a
       negative sign in $codepoint.

       Normalization Forms


       "$NFD_string = NFD($string)"
           returns the Normalization Form D (formed by canonical
           decomposition).

       "$NFC_string = NFC($string)"
           returns the Normalization Form C (formed by canonical
           decomposition followed by canonical composition).

       "$NFKD_string = NFKD($string)"
           returns the Normalization Form KD (formed by compati-
           bility decomposition).

       "$NFKC_string = NFKC($string)"
           returns the Normalization Form KC (formed by



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ext::Unicode::NorPerlzProgrext::Unicode::Normalize::Normalize(3p)


           compatibility decomposition followed by canonical com-
           position).

       "$FCD_string = FCD($string)"
           If the given string is in FCD ("Fast C or D" form; cf.
           UTN #5), returns it without modification; otherwise
           returns an FCD string.

           Note: FCD is not always unique, then plural forms may
           be equivalent each other. "FCD()" will return one of
           these equivalent forms.

       "$FCC_string = FCC($string)"
           returns the FCC form ("Fast C Contiguous"; cf. UTN
           #5).

           Note: FCC is unique, as well as four normalization
           forms (NF*).

       "$normalized_string = normalize($form_name, $string)"
           As $form_name, one of the following names must be
           given.

             'C'  or 'NFC'  for Normalization Form C  (UAX #15)
             'D'  or 'NFD'  for Normalization Form D  (UAX #15)
             'KC' or 'NFKC' for Normalization Form KC (UAX #15)
             'KD' or 'NFKD' for Normalization Form KD (UAX #15)

             'FCD'          for "Fast C or D" Form  (UTN #5)
             'FCC'          for "Fast C Contiguous" (UTN #5)

       Decomposition and Composition


       "$decomposed_string = decompose($string)"
       "$decomposed_string = decompose($string, $useCompatMap-
       ping)"
           Decomposes the specified string and returns the
           result.

           If the second parameter (a boolean) is omitted or
           false, decomposes it using the Canonical Decomposition
           Mapping.  If true, decomposes it using the Compatibil-
           ity Decomposition Mapping.

           The string returned is not always in NFD/NFKD.
           Reordering may be required.

               $NFD_string  = reorder(decompose($string));       # eq. to NFD()
               $NFKD_string = reorder(decompose($string, TRUE)); # eq. to NFKD()

       "$reordered_string  = reorder($string)"
           Reorders the combining characters and the like in the
           canonical ordering and returns the result.



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ext::Unicode::NorPerlzProgrext::Unicode::Normalize::Normalize(3p)


           E.g., when you have a list of NFD/NFKD strings, you
           can get the concatenated NFD/NFKD string from them,
           saying

               $concat_NFD  = reorder(join '', @NFD_strings);
               $concat_NFKD = reorder(join '', @NFKD_strings);

       "$composed_string   = compose($string)"
           Returns the string where composable pairs are com-
           posed.

           E.g., when you have a NFD/NFKD string, you can get its
           NFC/NFKC string, saying

               $NFC_string  = compose($NFD_string);
               $NFKC_string = compose($NFKD_string);

       Quick Check

       (see Annex 8, UAX #15; and DerivedNormalizationProps.txt)

       The following functions check whether the string is in
       that normalization form.

       The result returned will be:

           YES     The string is in that normalization form.
           NO      The string is not in that normalization form.
           MAYBE   Dubious. Maybe yes, maybe no.

       "$result = checkNFD($string)"
           returns true (1) if "YES"; false ("empty string") if
           "NO".

       "$result = checkNFC($string)"
           returns true (1) if "YES"; false ("empty string") if
           "NO"; "undef" if "MAYBE".

       "$result = checkNFKD($string)"
           returns true (1) if "YES"; false ("empty string") if
           "NO".

       "$result = checkNFKC($string)"
           returns true (1) if "YES"; false ("empty string") if
           "NO"; "undef" if "MAYBE".

       "$result = checkFCD($string)"
           returns true (1) if "YES"; false ("empty string") if
           "NO".

       "$result = checkFCC($string)"
           returns true (1) if "YES"; false ("empty string") if
           "NO"; "undef" if "MAYBE".




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ext::Unicode::NorPerlzProgrext::Unicode::Normalize::Normalize(3p)


           If a string is not in FCD, it must not be in FCC.  So
           "checkFCC($not_FCD_string)" should return "NO".

       "$result = check($form_name, $string)"
           returns true (1) if "YES"; false ("empty string") if
           "NO"; "undef" if "MAYBE".

           As $form_name, one of the following names must be
           given.

             'C'  or 'NFC'  for Normalization Form C  (UAX #15)
             'D'  or 'NFD'  for Normalization Form D  (UAX #15)
             'KC' or 'NFKC' for Normalization Form KC (UAX #15)
             'KD' or 'NFKD' for Normalization Form KD (UAX #15)

             'FCD'          for "Fast C or D" Form  (UTN #5)
             'FCC'          for "Fast C Contiguous" (UTN #5)

       Note

       In the cases of NFD, NFKD, and FCD, the answer must be
       either "YES" or "NO". The answer "MAYBE" may be returned
       in the cases of NFC, NFKC, and FCC.

       A "MAYBE" string should contain at least one combining
       character or the like. For example, "COMBINING ACUTE
       ACCENT" has the MAYBE_NFC/MAYBE_NFKC property.

       Both "checkNFC("A\N{COMBINING ACUTE ACCENT}")" and "check-
       NFC("B\N{COMBINING ACUTE ACCENT}")" will return "MAYBE".
       "A\N{COMBINING ACUTE ACCENT}" is not in NFC (its NFC is
       "\N{LATIN CAPITAL LETTER A WITH ACUTE}"), while "B\N{COM-
       BINING ACUTE ACCENT}" is in NFC.

       If you want to check exactly, compare the string with its
       NFC/NFKC/FCC.

           if ($string eq NFC($string)) {
               # $string is exactly normalized in NFC;
           } else {
               # $string is not normalized in NFC;
           }

           if ($string eq NFKC($string)) {
               # $string is exactly normalized in NFKC;
           } else {
               # $string is not normalized in NFKC;
           }

       Character Data

       These functions are interface of character data used
       internally.  If you want only to get Unicode normalization
       forms, you don't need call them yourself.



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ext::Unicode::NorPerlzProgrext::Unicode::Normalize::Normalize(3p)


       "$canonical_decomposed = getCanon($codepoint)"
           If the character of the specified codepoint is canoni-
           cally decomposable (including Hangul Syllables),
           returns the completely decomposed string canonically
           equivalent to it.

           If it is not decomposable, returns "undef".

       "$compatibility_decomposed = getCompat($codepoint)"
           If the character of the specified codepoint is compat-
           ibility decomposable (including Hangul Syllables),
           returns the completely decomposed string compatibility
           equivalent to it.

           If it is not decomposable, returns "undef".

       "$codepoint_composite = getComposite($codepoint_here,
       $code- point_next)"
           If two characters here and next (as codepoints) are
           composable (including Hangul Jamo/Syllables and Compo-
           sition Exclusions), returns the codepoint of the com-
           posite.

           If they are not composable, returns "undef".

       "$combining_class = getCombinClass($codepoint)"
           Returns the combining class of the character as an
           integer.

       "$is_exclusion = isExclusion($codepoint)"
           Returns a boolean whether the character of the speci-
           fied codepoint is a composition exclusion.

       "$is_singleton = isSingleton($codepoint)"
           Returns a boolean whether the character of the speci-
           fied codepoint is a singleton.

       "$is_non_starter_decomposition = isNonStDecomp($code-
       point)"
           Returns a boolean whether the canonical decomposition
           of the character of the specified codepoint is a Non-
           Starter Decomposition.

       "$may_be_composed_with_prev_char = isComp2nd($codepoint)"
           Returns a boolean whether the character of the speci-
           fied codepoint may be composed with the previous one
           in a certain composition (including Hangul Composi-
           tions, but excluding Composition Exclusions and Non-
           Starter Decompositions).

EXPORT
       "NFC", "NFD", "NFKC", "NFKD": by default.

       "normalize" and other some functions: on request.



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ext::Unicode::NorPerlzProgrext::Unicode::Normalize::Normalize(3p)


CAVEATS
       Perl's version vs. Unicode version
           Since this module refers to perl core's Unicode
           database in the directory /lib/unicore (or formerly
           /lib/unicode), the Unicode version of normalization
           implemented by this module depends on your perl's ver-
           sion.

               perl's version         implemented Unicode version
                  5.6.1                  3.0.1
                  5.7.2                  3.1.0
                  5.7.3                  3.1.1 (same normalized form as that of 3.1.0)
                  5.8.0                  3.2.0
                5.8.1-5.8.3              4.0.0
                5.8.4-5.8.6 (latest)     4.0.1 (same normalized form as that of 4.0.0)

       Correction of decomposition mapping
           In older Unicode versions, a small number of charac-
           ters (all of which are CJK compatibility ideographs as
           far as they have been found) may have an erroneous
           decomposition mapping (see NormalizationCorrec-
           tions.txt).  Anyhow, this module will neither refer to
           NormalizationCorrections.txt nor provide any specific
           version of normalization. Therefore this module run-
           ning on an older perl with an older Unicode database
           may use the erroneous decomposition mapping blindly
           conforming to the Unicode database.

       Revised definition of canonical composition
           In Unicode 4.1.0, the definition D2 of canonical com-
           position (which affects NFC and NFKC) has been changed
           (see Public Review Issue #29 and recent UAX #15). This
           module has used the newer definition since the version
           0.07 (Oct 31, 2001).  This module does not support
           normalization according to the older definition, even
           if the Unicode version implemented by perl is lower
           than 4.1.0.

AUTHOR
       SADAHIRO Tomoyuki <SADAHIRO@cpan.org>

       Copyright(C) 2001-2005, SADAHIRO Tomoyuki. Japan. All
       rights reserved.

       This module is free software; you can redistribute it
       and/or modify it under the same terms as Perl itself.

SEE ALSO
       http://www.unicode.org/reports/tr15/
           Unicode Normalization Forms - UAX #15

       http://www.unicode.org/Public/UNIDATA/DerivedNormaliza-
       tion- Props.txt
           Derived Normalization Properties



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ext::Unicode::NorPerlzProgrext::Unicode::Normalize::Normalize(3p)


       http://www.unicode.org/Public/UNIDATA/NormalizationCorrec-
       tions.txt
           Normalization Corrections

       http://www.unicode.org/review/pr-29.html
           Public Review Issue #29: Normalization Issue

       http://www.unicode.org/notes/tn5/
           Canonical Equivalence in Applications - UTN #5
















































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