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Diffstat (limited to 'Master/tlpkg/tlperl/lib/_charnames.pm')
-rw-r--r-- | Master/tlpkg/tlperl/lib/_charnames.pm | 764 |
1 files changed, 764 insertions, 0 deletions
diff --git a/Master/tlpkg/tlperl/lib/_charnames.pm b/Master/tlpkg/tlperl/lib/_charnames.pm new file mode 100644 index 00000000000..62ee39560de --- /dev/null +++ b/Master/tlpkg/tlperl/lib/_charnames.pm @@ -0,0 +1,764 @@ +# !!!!!!! INTERNAL PERL USE ONLY !!!!!!! +# This helper module is for internal use by core Perl only. This module is +# subject to change or removal at any time without notice. Don't use it +# directly. Use the public <charnames> module instead. + +package _charnames; +use strict; +use warnings; +use File::Spec; +our $VERSION = '1.31'; +use unicore::Name; # mktables-generated algorithmically-defined names + +use bytes (); # for $bytes::hint_bits +use re "/aa"; # Everything in here should be ASCII + +$Carp::Internal{ (__PACKAGE__) } = 1; + +# Translate between Unicode character names and their code points. This is a +# submodule of package <charnames>, used to allow \N{...} to be autoloaded, +# but it was decided not to autoload the various functions in charnames; the +# splitting allows this behavior. +# +# The official names with their code points are stored in a table in +# lib/unicore/Name.pl which is read in as a large string (almost 3/4 Mb in +# Unicode 6.0). Each code point/name combination is separated by a \n in the +# string. (Some of the CJK and the Hangul syllable names are determined +# instead algorithmically via subroutines stored instead in +# lib/unicore/Name.pm). Because of the large size of this table, it isn't +# converted into hashes for faster lookup. +# +# But, user defined aliases are stored in their own hashes, as are Perl +# extensions to the official names. These are checked first before looking at +# the official table. +# +# Basically, the table is grepped for the input code point (viacode()) or +# name (the other functions), and the corresponding value on the same line is +# returned. The grepping is done by turning the input into a regular +# expression. Thus, the same table does double duty, used by both name and +# code point lookup. (If we were to have hashes, we would need two, one for +# each lookup direction.) +# +# For loose name matching, the logical thing would be to have a table +# with all the ignorable characters squeezed out, and then grep it with the +# similiarly-squeezed input name. (And this is in fact how the lookups are +# done with the small Perl extension hashes.) But since we need to be able to +# go from code point to official name, the original table would still need to +# exist. Due to the large size of the table, it was decided to not read +# another very large string into memory for a second table. Instead, the +# regular expression of the input name is modified to have optional spaces and +# dashes between characters. For example, in strict matching, the regular +# expression would be: +# qr/\tDIGIT ONE$/m +# Under loose matching, the blank would be squeezed out, and the re would be: +# qr/\tD[- ]?I[- ]?G[- ]?I[- ]?T[- ]?O[- ]?N[- ]?E$/m +# which matches a blank or dash between any characters in the official table. +# +# This is also how script lookup is done. Basically the re looks like +# qr/ (?:LATIN|GREEK|CYRILLIC) (?:SMALL )?LETTER $name/ +# where $name is the loose or strict regex for the remainder of the name. + +# The hashes are stored as utf8 strings. This makes it easier to deal with +# sequences. I (khw) also tried making Name.pl utf8, but it slowed things +# down by a factor of 7. I then tried making Name.pl store the ut8 +# equivalents but not calling them utf8. That led to similar speed as leaving +# it alone, but since that is harder for a human to parse, I left it as-is. + +my %system_aliases = ( + + 'SINGLE-SHIFT 2' => pack("U", 0x8E), + 'SINGLE-SHIFT 3' => pack("U", 0x8F), + 'PRIVATE USE 1' => pack("U", 0x91), + 'PRIVATE USE 2' => pack("U", 0x92), +); + +# These are the aliases above that differ under :loose and :full matching +# because the :full versions have blanks or hyphens in them. +#my %loose_system_aliases = ( +#); + +my %deprecated_aliases = ( + # Use of these gives deprecated message. + # Unicode 6.0 co-opted this for U+1F514, so deprecate it for now. + 'BELL' => pack("U", 0x07), +); + +#my %loose_deprecated_aliases = ( +#); + +# These are special cased in :loose matching, differing only in a medial +# hyphen +my $HANGUL_JUNGSEONG_O_E_utf8 = pack("U", 0x1180); +my $HANGUL_JUNGSEONG_OE_utf8 = pack("U", 0x116C); + + +my $txt; # The table of official character names + +my %full_names_cache; # Holds already-looked-up names, so don't have to +# re-look them up again. The previous versions of charnames had scoping +# bugs. For example if we use script A in one scope and find and cache +# what Z resolves to, we can't use that cache in a different scope that +# uses script B instead of A, as Z might be an entirely different letter +# there; or there might be different aliases in effect in different +# scopes, or :short may be in effect or not effect in different scopes, +# or various combinations thereof. This was solved in this version +# mostly by moving things to %^H. But some things couldn't be moved +# there. One of them was the cache of runtime looked-up names, in part +# because %^H is read-only at runtime. I (khw) don't know why the cache +# was run-time only in the previous versions: perhaps oversight; perhaps +# that compile time looking doesn't happen in a loop so didn't think it +# was worthwhile; perhaps not wanting to make the cache too large. But +# I decided to make it compile time as well; this could easily be +# changed. +# Anyway, this hash is not scoped, and is added to at runtime. It +# doesn't have scoping problems because the data in it is restricted to +# official names, which are always invariant, and we only set it and +# look at it at during :full lookups, so is unaffected by any other +# scoped options. I put this in to maintain parity with the older +# version. If desired, a %short_names cache could also be made, as well +# as one for each script, say in %script_names_cache, with each key +# being a hash for a script named in a 'use charnames' statement. I +# decided not to do that for now, just because it's added complication, +# and because I'm just trying to maintain parity, not extend it. + +# Like %full_names_cache, but for use when :loose is in effect. There needs +# to be two caches because :loose may not be in effect for a scope, and a +# loose name could inappropriately be returned when only exact matching is +# called for. +my %loose_names_cache; + +# Designed so that test decimal first, and then hex. Leading zeros +# imply non-decimal, as do non-[0-9] +my $decimal_qr = qr/^[1-9]\d*$/; + +# Returns the hex number in $1. +my $hex_qr = qr/^(?:[Uu]\+|0[xX])?([[:xdigit:]]+)$/; + +sub croak +{ + require Carp; goto &Carp::croak; +} # croak + +sub carp +{ + require Carp; goto &Carp::carp; +} # carp + +sub alias (@) # Set up a single alias +{ + my $alias = ref $_[0] ? $_[0] : { @_ }; + foreach my $name (keys %$alias) { + my $value = $alias->{$name}; + next unless defined $value; # Omit if screwed up. + + # Is slightly slower to just after this statement see if it is + # decimal, since we already know it is after having converted from + # hex, but makes the code easier to maintain, and is called + # infrequently, only at compile-time + if ($value !~ $decimal_qr && $value =~ $hex_qr) { + $value = CORE::hex $1; + } + if ($value =~ $decimal_qr) { + no warnings qw(non_unicode surrogate nonchar); # Allow any non-malformed + $^H{charnames_ord_aliases}{$name} = pack("U", $value); + + # Use a canonical form. + $^H{charnames_inverse_ords}{sprintf("%05X", $value)} = $name; + } + else { + # XXX validate syntax when deprecation cycle complete. ie. start + # with an alpha only, etc. + $^H{charnames_name_aliases}{$name} = $value; + } + } +} # alias + +sub not_legal_use_bytes_msg { + my ($name, $utf8) = @_; + my $return; + + if (length($utf8) == 1) { + $return = sprintf("Character 0x%04x with name '%s' is", ord $utf8, $name); + } else { + $return = sprintf("String with name '%s' (and ordinals %s) contains character(s)", $name, join(" ", map { sprintf "0x%04X", ord $_ } split(//, $utf8))); + } + return $return . " above 0xFF with 'use bytes' in effect"; +} + +sub alias_file ($) # Reads a file containing alias definitions +{ + my ($arg, $file) = @_; + if (-f $arg && File::Spec->file_name_is_absolute ($arg)) { + $file = $arg; + } + elsif ($arg =~ m/^\w+$/) { + $file = "unicore/${arg}_alias.pl"; + } + else { + croak "Charnames alias files can only have identifier characters"; + } + if (my @alias = do $file) { + @alias == 1 && !defined $alias[0] and + croak "$file cannot be used as alias file for charnames"; + @alias % 2 and + croak "$file did not return a (valid) list of alias pairs"; + alias (@alias); + return (1); + } + 0; +} # alias_file + +# For use when don't import anything. This structure must be kept in +# sync with the one that import() fills up. +my %dummy_H = ( + charnames_stringified_names => "", + charnames_stringified_ords => "", + charnames_scripts => "", + charnames_full => 1, + charnames_loose => 0, + charnames_short => 0, + ); + + +sub lookup_name ($$$) { + my ($name, $wants_ord, $runtime) = @_; + + # Lookup the name or sequence $name in the tables. If $wants_ord is false, + # returns the string equivalent of $name; if true, returns the ordinal value + # instead, but in this case $name must not be a sequence; otherwise undef is + # returned and a warning raised. $runtime is 0 if compiletime, otherwise + # gives the number of stack frames to go back to get the application caller + # info. + # If $name is not found, returns undef in runtime with no warning; and in + # compiletime, the Unicode replacement character, with a warning. + + # It looks first in the aliases, then in the large table of official Unicode + # names. + + my $utf8; # The string result + my $save_input; + + if ($runtime) { + + my $hints_ref = (caller($runtime))[10]; + + # If we didn't import anything (which happens with 'use charnames ()', + # substitute a dummy structure. + $hints_ref = \%dummy_H if ! defined $hints_ref + || (! defined $hints_ref->{charnames_full} + && ! defined $hints_ref->{charnames_loose}); + + # At runtime, but currently not at compile time, $^H gets + # stringified, so un-stringify back to the original data structures. + # These get thrown away by perl before the next invocation + # Also fill in the hash with the non-stringified data. + # N.B. New fields must be also added to %dummy_H + + %{$^H{charnames_name_aliases}} = split ',', + $hints_ref->{charnames_stringified_names}; + %{$^H{charnames_ord_aliases}} = split ',', + $hints_ref->{charnames_stringified_ords}; + $^H{charnames_scripts} = $hints_ref->{charnames_scripts}; + $^H{charnames_full} = $hints_ref->{charnames_full}; + $^H{charnames_loose} = $hints_ref->{charnames_loose}; + $^H{charnames_short} = $hints_ref->{charnames_short}; + } + + my $loose = $^H{charnames_loose}; + my $lookup_name; # Input name suitably modified for grepping for in the + # table + + # User alias should be checked first or else can't override ours, and if we + # were to add any, could conflict with theirs. + if (exists $^H{charnames_ord_aliases}{$name}) { + $utf8 = $^H{charnames_ord_aliases}{$name}; + } + elsif (exists $^H{charnames_name_aliases}{$name}) { + $name = $^H{charnames_name_aliases}{$name}; + $save_input = $lookup_name = $name; # Cache the result for any error + # message + # The aliases are documented to not match loosely, so change loose match + # into full. + if ($loose) { + $loose = 0; + $^H{charnames_full} = 1; + } + } + else { + + # Here, not a user alias. That means that loose matching may be in + # effect; will have to modify the input name. + $lookup_name = $name; + if ($loose) { + $lookup_name = uc $lookup_name; + + # Squeeze out all underscores + $lookup_name =~ s/_//g; + + # Remove all medial hyphens + $lookup_name =~ s/ (?<= \S ) - (?= \S )//gx; + + # Squeeze out all spaces + $lookup_name =~ s/\s//g; + } + + # Here, $lookup_name has been modified as necessary for looking in the + # hashes. Check the system alias files next. Most of these aliases are + # the same for both strict and loose matching. To save space, the ones + # which differ are in their own separate hash, which is checked if loose + # matching is selected and the regular match fails. To save time, the + # loose hashes could be expanded to include all aliases, and there would + # only have to be one check. But if someone specifies :loose, they are + # interested in convenience over speed, and the time for this second check + # is miniscule compared to the rest of the routine. + if (exists $system_aliases{$lookup_name}) { + $utf8 = $system_aliases{$lookup_name}; + } + # There are currently no entries in this hash, so don't waste time looking + # for them. But the code is retained for the unlikely possibility that + # some will be added in the future. +# elsif ($loose && exists $loose_system_aliases{$lookup_name}) { +# $utf8 = $loose_system_aliases{$lookup_name}; +# } + if (exists $deprecated_aliases{$lookup_name}) { + require warnings; + warnings::warnif('deprecated', + "Unicode character name \"$name\" is deprecated, use \"" + . viacode(ord $deprecated_aliases{$lookup_name}) + . "\" instead"); + $utf8 = $deprecated_aliases{$lookup_name}; + } + # There are currently no entries in this hash, so don't waste time looking + # for them. But the code is retained for the unlikely possibility that + # some will be added in the future. +# elsif ($loose && exists $loose_deprecated_aliases{$lookup_name}) { +# require warnings; +# warnings::warnif('deprecated', +# "Unicode character name \"$name\" is deprecated, use \"" +# . viacode(ord $loose_deprecated_aliases{$lookup_name}) +# . "\" instead"); +# $utf8 = $loose_deprecated_aliases{$lookup_name}; +# } + } + + my @off; # Offsets into table of pattern match begin and end + + # If haven't found it yet... + if (! defined $utf8) { + + # See if has looked this input up earlier. + if (! $loose && $^H{charnames_full} && exists $full_names_cache{$name}) { + $utf8 = $full_names_cache{$name}; + } + elsif ($loose && exists $loose_names_cache{$name}) { + $utf8 = $loose_names_cache{$name}; + } + else { # Here, must do a look-up + + # If full or loose matching succeeded, points to where to cache the + # result + my $cache_ref; + + ## Suck in the code/name list as a big string. + ## Lines look like: + ## "00052\tLATIN CAPITAL LETTER R\n" + # or + # "0052 0303\tLATIN CAPITAL LETTER R WITH TILDE\n" + $txt = do "unicore/Name.pl" unless $txt; + + ## @off will hold the index into the code/name string of the start and + ## end of the name as we find it. + + ## If :loose, look for a loose match; if :full, look for the name + ## exactly + # First, see if the name is one which is algorithmically determinable. + # The subroutine is included in Name.pl. The table contained in + # $txt doesn't contain these. Experiments show that checking + # for these before checking for the regular names has no + # noticeable impact on performance for the regular names, but + # the other way around slows down finding these immensely. + # Algorithmically determinables are not placed in the cache because + # that uses up memory, and finding these again is fast. + if (($loose || $^H{charnames_full}) + && (defined (my $ord = charnames::name_to_code_point_special($lookup_name, $loose)))) + { + $utf8 = pack("U", $ord); + } + else { + + # Not algorithmically determinable; look up in the table. The name + # will be turned into a regex, so quote any meta characters. + $lookup_name = quotemeta $lookup_name; + + if ($loose) { + + # For loose matches, $lookup_name has already squeezed out the + # non-essential characters. We have to add in code to make the + # squeezed version match the non-squeezed equivalent in the table. + # The only remaining hyphens are ones that start or end a word in + # the original. They have been quoted in $lookup_name so they look + # like "\-". Change all other characters except the backslash + # quotes for any metacharacters, and the final character, so that + # e.g., COLON gets transformed into: /C[- ]?O[- ]?L[- ]?O[- ]?N/ + $lookup_name =~ s/ (?! \\ -) # Don't do this to the \- sequence + ( [^-\\] ) # Nor the "-" within that sequence, + # nor the "\" that quotes metachars, + # but otherwise put the char into $1 + (?=.) # And don't do it for the final char + /$1\[- \]?/gx; # And add an optional blank or + # '-' after each $1 char + + # Those remaining hyphens were originally at the beginning or end of + # a word, so they can match either a blank before or after, but not + # both. (Keep in mind that they have been quoted, so are a '\-' + # sequence) + $lookup_name =~ s/\\ -/(?:- | -)/xg; + } + + # Do the lookup in the full table if asked for, and if succeeds + # save the offsets and set where to cache the result. + if (($loose || $^H{charnames_full}) && $txt =~ /\t$lookup_name$/m) { + @off = ($-[0] + 1, $+[0]); # The 1 is for the tab + $cache_ref = ($loose) ? \%loose_names_cache : \%full_names_cache; + } + else { + + # Here, didn't look for, or didn't find the name. + # If :short is allowed, see if input is like "greek:Sigma". + # Keep in mind that $lookup_name has had the metas quoted. + my $scripts_trie = ""; + my $name_has_uppercase; + if (($^H{charnames_short}) + && $lookup_name =~ /^ (?: \\ \s)* # Quoted space + (.+?) # $1 = the script + (?: \\ \s)* + \\ : # Quoted colon + (?: \\ \s)* + (.+?) # $2 = the name + (?: \\ \s)* $ + /xs) + { + # Even in non-loose matching, the script traditionally has been + # case insensitve + $scripts_trie = "\U$1"; + $lookup_name = $2; + + # Use original name to find its input casing, but ignore the + # script part of that to make the determination. + $save_input = $name if ! defined $save_input; + $name =~ s/.*?://; + $name_has_uppercase = $name =~ /[[:upper:]]/; + } + else { # Otherwise look in allowed scripts + $scripts_trie = $^H{charnames_scripts}; + + # Use original name to find its input casing + $name_has_uppercase = $name =~ /[[:upper:]]/; + } + + my $case = $name_has_uppercase ? "CAPITAL" : "SMALL"; + if (! $scripts_trie + || $txt !~ + /\t (?: $scripts_trie ) \ (?:$case\ )? LETTER \ \U$lookup_name $/xm) + { + # Here we still don't have it, give up. + return if $runtime; + + # May have zapped input name, get it again. + $name = (defined $save_input) ? $save_input : $_[0]; + carp "Unknown charname '$name'"; + return ($wants_ord) ? 0xFFFD : pack("U", 0xFFFD); + } + + # Here have found the input name in the table. + @off = ($-[0] + 1, $+[0]); # The 1 is for the tab + } + + # Here, the input name has been found; we haven't set up the output, + # but we know where in the string + # the name starts. The string is set up so that for single characters + # (and not named sequences), the name is preceded immediately by a + # tab and 5 hex digits for its code, with a \n before those. Named + # sequences won't have the 7th preceding character be a \n. + # (Actually, for the very first entry in the table this isn't strictly + # true: subtracting 7 will yield -1, and the substr below will + # therefore yield the very last character in the table, which should + # also be a \n, so the statement works anyway.) + if (substr($txt, $off[0] - 7, 1) eq "\n") { + $utf8 = pack("U", CORE::hex substr($txt, $off[0] - 6, 5)); + + # Handle the single loose matching special case, in which two names + # differ only by a single medial hyphen. If the original had a + # hyphen (or more) in the right place, then it is that one. + $utf8 = $HANGUL_JUNGSEONG_O_E_utf8 + if $loose + && $utf8 eq $HANGUL_JUNGSEONG_OE_utf8 + && $name =~ m/O \s* - [-\s]* E/ix; + # Note that this wouldn't work if there were a 2nd + # OE in the name + } + else { + + # Here, is a named sequence. Need to go looking for the beginning, + # which is just after the \n from the previous entry in the table. + # The +1 skips past that newline, or, if the rindex() fails, to put + # us to an offset of zero. + my $charstart = rindex($txt, "\n", $off[0] - 7) + 1; + $utf8 = pack("U*", map { CORE::hex } + split " ", substr($txt, $charstart, $off[0] - $charstart - 1)); + } + } + + # Cache the input so as to not have to search the large table + # again, but only if it came from the one search that we cache. + # (Haven't bothered with the pain of sorting out scoping issues for the + # scripts searches.) + $cache_ref->{$name} = $utf8 if defined $cache_ref; + } + } + + + # Here, have the utf8. If the return is to be an ord, must be any single + # character. + if ($wants_ord) { + return ord($utf8) if length $utf8 == 1; + } + else { + + # Here, wants string output. If utf8 is acceptable, just return what + # we've got; otherwise attempt to convert it to non-utf8 and return that. + my $in_bytes = ($runtime) + ? (caller $runtime)[8] & $bytes::hint_bits + : $^H & $bytes::hint_bits; + return $utf8 if (! $in_bytes || utf8::downgrade($utf8, 1)) # The 1 arg + # means don't die on failure + } + + # Here, there is an error: either there are too many characters, or the + # result string needs to be non-utf8, and at least one character requires + # utf8. Prefer any official name over the input one for the error message. + if (@off) { + $name = substr($txt, $off[0], $off[1] - $off[0]) if @off; + } + else { + $name = (defined $save_input) ? $save_input : $_[0]; + } + + if ($wants_ord) { + # Only way to get here in this case is if result too long. Message + # assumes that our only caller that requires single char result is + # vianame. + carp "charnames::vianame() doesn't handle named sequences ($name). Use charnames::string_vianame() instead"; + return; + } + + # Only other possible failure here is from use bytes. + if ($runtime) { + carp not_legal_use_bytes_msg($name, $utf8); + return; + } else { + croak not_legal_use_bytes_msg($name, $utf8); + } + +} # lookup_name + +sub charnames { + + # For \N{...}. Looks up the character name and returns the string + # representation of it. + + # The first 0 arg means wants a string returned; the second that we are in + # compile time + return lookup_name($_[0], 0, 0); +} + +sub import +{ + shift; ## ignore class name + + if (not @_) { + carp("'use charnames' needs explicit imports list"); + } + $^H{charnames} = \&charnames ; + $^H{charnames_ord_aliases} = {}; + $^H{charnames_name_aliases} = {}; + $^H{charnames_inverse_ords} = {}; + # New fields must be added to %dummy_H, and the code in lookup_name() + # that copies fields from the runtime structure + + ## + ## fill %h keys with our @_ args. + ## + my ($promote, %h, @args) = (0); + while (my $arg = shift) { + if ($arg eq ":alias") { + @_ or + croak ":alias needs an argument in charnames"; + my $alias = shift; + if (ref $alias) { + ref $alias eq "HASH" or + croak "Only HASH reference supported as argument to :alias"; + alias ($alias); + next; + } + if ($alias =~ m{:(\w+)$}) { + $1 eq "full" || $1 eq "loose" || $1 eq "short" and + croak ":alias cannot use existing pragma :$1 (reversed order?)"; + alias_file ($1) and $promote = 1; + next; + } + alias_file ($alias); + next; + } + if (substr($arg, 0, 1) eq ':' + and ! ($arg eq ":full" || $arg eq ":short" || $arg eq ":loose")) + { + warn "unsupported special '$arg' in charnames"; + next; + } + push @args, $arg; + } + + @args == 0 && $promote and @args = (":full"); + @h{@args} = (1) x @args; + + # Don't leave these undefined as are tested for in lookup_names + $^H{charnames_full} = delete $h{':full'} || 0; + $^H{charnames_loose} = delete $h{':loose'} || 0; + $^H{charnames_short} = delete $h{':short'} || 0; + my @scripts = map { uc quotemeta } keys %h; + + ## + ## If utf8? warnings are enabled, and some scripts were given, + ## see if at least we can find one letter from each script. + ## + if (warnings::enabled('utf8') && @scripts) { + $txt = do "unicore/Name.pl" unless $txt; + + for my $script (@scripts) { + if (not $txt =~ m/\t$script (?:CAPITAL |SMALL )?LETTER /) { + warnings::warn('utf8', "No such script: '$script'"); + $script = quotemeta $script; # Escape it, for use in the re. + } + } + } + + # %^H gets stringified, so serialize it ourselves so can extract the + # real data back later. + $^H{charnames_stringified_ords} = join ",", %{$^H{charnames_ord_aliases}}; + $^H{charnames_stringified_names} = join ",", %{$^H{charnames_name_aliases}}; + $^H{charnames_stringified_inverse_ords} = join ",", %{$^H{charnames_inverse_ords}}; + + # Modify the input script names for loose name matching if that is also + # specified, similar to the way the base character name is prepared. They + # don't (currently, and hopefully never will) have dashes. These go into a + # regex, and have already been uppercased and quotemeta'd. Squeeze out all + # input underscores, blanks, and dashes. Then convert so will match a blank + # between any characters. + if ($^H{charnames_loose}) { + for (my $i = 0; $i < @scripts; $i++) { + $scripts[$i] =~ s/[_ -]//g; + $scripts[$i] =~ s/ ( [^\\] ) (?= . ) /$1\\ ?/gx; + } + } + + $^H{charnames_scripts} = join "|", @scripts; # Stringifiy them as a trie +} # import + +# Cache of already looked-up values. This is set to only contain +# official values, and user aliases can't override them, so scoping is +# not an issue. +my %viacode; + +sub viacode { + + # Returns the name of the code point argument + + if (@_ != 1) { + carp "charnames::viacode() expects one argument"; + return; + } + + my $arg = shift; + + # This is derived from Unicode::UCD, where it is nearly the same as the + # function _getcode(), but here it makes sure that even a hex argument + # has the proper number of leading zeros, which is critical in + # matching against $txt below + # Must check if decimal first; see comments at that definition + my $hex; + if ($arg =~ $decimal_qr) { + $hex = sprintf "%05X", $arg; + } elsif ($arg =~ $hex_qr) { + # Below is the line that differs from the _getcode() source + $hex = sprintf "%05X", hex $1; + } else { + carp("unexpected arg \"$arg\" to charnames::viacode()"); + return; + } + + return $viacode{$hex} if exists $viacode{$hex}; + + my $return; + + # If the code point is above the max in the table, there's no point + # looking through it. Checking the length first is slightly faster + if (length($hex) <= 5 || CORE::hex($hex) <= 0x10FFFF) { + $txt = do "unicore/Name.pl" unless $txt; + + # See if the name is algorithmically determinable. + my $algorithmic = charnames::code_point_to_name_special(CORE::hex $hex); + if (defined $algorithmic) { + $viacode{$hex} = $algorithmic; + return $algorithmic; + } + + # Return the official name, if exists. It's unclear to me (khw) at + # this juncture if it is better to return a user-defined override, so + # leaving it as is for now. + if ($txt =~ m/^$hex\t/m) { + + # The name starts with the next character and goes up to the + # next new-line. Using capturing parentheses above instead of + # @+ more than doubles the execution time in Perl 5.13 + $return = substr($txt, $+[0], index($txt, "\n", $+[0]) - $+[0]); + + # If not one of these 4 code points, return what we've found. + if ($hex !~ / ^ 000 (?: 8[014] | 99 ) $ /x) { + $viacode{$hex} = $return; + return $return; + } + + # For backwards compatibility, we don't return the official name of + # the 4 code points if there are user-defined aliases for them -- so + # continue looking. + } + } + + # See if there is a user name for it, before giving up completely. + # First get the scoped aliases, give up if have none. + my $H_ref = (caller(1))[10]; + return if ! defined $return + && (! defined $H_ref + || ! exists $H_ref->{charnames_stringified_inverse_ords}); + + my %code_point_aliases; + if (defined $H_ref->{charnames_stringified_inverse_ords}) { + %code_point_aliases = split ',', + $H_ref->{charnames_stringified_inverse_ords}; + return $code_point_aliases{$hex} if exists $code_point_aliases{$hex}; + } + + # Here there is no user-defined alias, return any official one. + return $return if defined $return; + + if (CORE::hex($hex) > 0x10FFFF) { + carp "Unicode characters only allocated up to U+10FFFF (you asked for U+$hex)"; + } + return; + +} # _viacode + +1; + +# ex: set ts=8 sts=2 sw=2 et: |