X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Futf8.pm;h=b7c938e17eda0774f56440f5cd87a1f434d541e6;hb=002b9267a385cf8ff0e7534241cdf3798da8636c;hp=f357dbf9b929b4ccdcffd135a453d8dab051adb6;hpb=63708e74df7f3113a5e81bbb8ac68dc55f350a2d;p=p5sagit%2Fp5-mst-13.2.git diff --git a/lib/utf8.pm b/lib/utf8.pm index f357dbf..b7c938e 100644 --- a/lib/utf8.pm +++ b/lib/utf8.pm @@ -2,7 +2,7 @@ package utf8; $utf8::hint_bits = 0x00800000; -our $VERSION = '1.02'; +our $VERSION = '1.05'; sub import { $^H |= $utf8::hint_bits; @@ -16,6 +16,7 @@ sub unimport { sub AUTOLOAD { require "utf8_heavy.pl"; goto &$AUTOLOAD if defined &$AUTOLOAD; + require Carp; Carp::croak("Undefined subroutine $AUTOLOAD called"); } @@ -31,9 +32,11 @@ utf8 - Perl pragma to enable/disable UTF-8 (or UTF-EBCDIC) in source code use utf8; no utf8; + # Convert a Perl scalar to/from UTF-8. $num_octets = utf8::upgrade($string); $success = utf8::downgrade($string[, FAIL_OK]); + # Change the native bytes of a Perl scalar to/from UTF-8 bytes. utf8::encode($string); utf8::decode($string); @@ -52,6 +55,11 @@ earlier than 5.6 allowed arbitrary bytes in source code, whereas in future we would like to standardize on the UTF-8 encoding for source text. +B The utility functions described below are +useful for their own purposes, but they are not really part of the +"pragmatic" effect. + Until UTF-8 becomes the default format for source text, either this pragma or the L pragma should be used to recognize UTF-8 in the source. When UTF-8 becomes the standard source format, this @@ -59,6 +67,9 @@ pragma will effectively become a no-op. For convenience in what follows the term I is used to refer to UTF-8 on ASCII and ISO Latin based platforms and UTF-EBCDIC on EBCDIC based platforms. +See also the effects of the C<-C> switch and its cousin, the +C<$ENV{PERL_UNICODE}>, in L. + Enabling the C pragma has the following effect: =over 4 @@ -97,46 +108,65 @@ the same as C. The following functions are defined in the C package by the Perl core. You do not need to say C to use these and in fact -you should not unless you really want to have UTF-8 source code. +you should not say that unless you really want to have UTF-8 source code. =over 4 =item * $num_octets = utf8::upgrade($string) -Converts (in-place) internal representation of string to Perl's -internal I form. Returns the number of octets necessary to -represent the string as I. Can be used to make sure that the -UTF-8 flag is on, so that C<\w> or C work as expected on strings -containing characters in the range 0x80-0xFF (oon ASCII and -derivatives). Note that this should not be used to convert a legacy -byte encoding to Unicode: use Encode for that. Affected by the -encoding pragma. +Converts in-place the octet sequence in the native encoding +(Latin-1 or EBCDIC) to the equivalent character sequence in I. +I<$string> already encoded as characters does no harm. +Returns the number of octets necessary to represent the string as I. +Can be used to make sure that the UTF-8 flag is on, +so that C<\w> or C work as Unicode on strings +containing characters in the range 0x80-0xFF (on ASCII and +derivatives). + +B +Therefore I is recommended for the general purposes. + +Affected by the encoding pragma. =item * $success = utf8::downgrade($string[, FAIL_OK]) -Converts (in-place) internal representation of string to be un-encoded -bytes. Returns true on success. On failure dies or, if the value of -FAIL_OK is true, returns false. Can be used to make sure that the -UTF-8 flag is off, e.g. when you want to make sure that the substr() -or length() function works with the usually faster byte algorithm. -Note that this should not be used to convert Unicode back to a legacy -byte encoding: use Encode for that. B affected by the encoding -pragma. +Converts in-place the character sequence in I +to the equivalent octet sequence in the native encoding (Latin-1 or EBCDIC). +I<$string> already encoded as octets does no harm. +Returns true on success. On failure dies or, if the value of +C is true, returns false. +Can be used to make sure that the UTF-8 flag is off, +e.g. when you want to make sure that the substr() or length() function +works with the usually faster byte algorithm. + +B +Therefore I is recommended for the general purposes. + +B affected by the encoding pragma. + +B this function is experimental and may change +or be removed without notice. =item * utf8::encode($string) -Converts (in-place) I<$string> from logical characters to octet -sequence representing it in Perl's I encoding. Returns -nothing. Same as Encode::encode_utf8(). Note that this should not be -used to convert a legacy byte encoding to Unicode: use Encode for -that. +Converts in-place the character sequence to the corresponding octet sequence +in I. The UTF-8 flag is turned off. Returns nothing. + +B +Therefore I is recommended for the general purposes. =item * utf8::decode($string) -Attempts to convert I<$string> in-place from Perl's I encoding -into logical characters. Returns nothing. Same as Encode::decode_utf8(). -Note that this should not be used to convert Unicode back to a legacy -byte encoding: use Encode for that. +Attempts to convert in-place the octet sequence in I +to the corresponding character sequence. The UTF-8 flag is turned on +only if the source string contains multiple-byte I characters. +If I<$string> is invalid as I, returns false; otherwise returns true. + +B +Therefore I is recommended for the general purposes. + +B this function is experimental and may change +or be removed without notice. =item * $flag = utf8::is_utf8(STRING) @@ -179,6 +209,6 @@ portable answers. =head1 SEE ALSO -L, L, L, L +L, L, L, L, L =cut