NAME
Ehebrew - Run-time routines for Hebrew.pm
SYNOPSIS
use Ehebrew;
Ehebrew::split(...);
Ehebrew::tr(...);
Ehebrew::chop(...);
Ehebrew::index(...);
Ehebrew::rindex(...);
Ehebrew::lc(...);
Ehebrew::lc_;
Ehebrew::lcfirst(...);
Ehebrew::lcfirst_;
Ehebrew::uc(...);
Ehebrew::uc_;
Ehebrew::ucfirst(...);
Ehebrew::ucfirst_;
Ehebrew::fc(...);
Ehebrew::fc_;
Ehebrew::ignorecase(...);
Ehebrew::capture(...);
Ehebrew::chr(...);
Ehebrew::chr_;
Ehebrew::glob(...);
Ehebrew::glob_;
# "no Ehebrew;" not supported
ABSTRACT
This module has run-time routines for use Hebrew software automatically, you do not have to use.
BUGS AND LIMITATIONS
I have tested and verified this software using the best of my ability. However, a software containing much regular expression is bound to contain some bugs. Thus, if you happen to find a bug that's in Hebrew software and not your own program, you can try to reduce it to a minimal test case and then report it to the following author's address. If you have an idea that could make this a more useful tool, please let everyone share it.
HISTORY
This Ehebrew module first appeared in ActivePerl Build 522 Built under MSWin32 Compiled at Nov 2 1999 09:52:28
AUTHOR
INABA Hitoshi <ina@cpan.org>
This project was originated by INABA Hitoshi. For any questions, use <ina@cpan.org> so we can share this file.
LICENSE AND COPYRIGHT
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
EXAMPLES
Split string
@split = Ehebrew::split(/pattern/,$string,$limit); @split = Ehebrew::split(/pattern/,$string); @split = Ehebrew::split(/pattern/); @split = Ehebrew::split('',$string,$limit); @split = Ehebrew::split('',$string); @split = Ehebrew::split(''); @split = Ehebrew::split(); @split = Ehebrew::split; This subroutine scans a string given by $string for separators, and splits the string into a list of substring, returning the resulting list value in list context or the count of substring in scalar context. Scalar context also causes split to write its result to @_, but this usage is deprecated. The separators are determined by repeated pattern matching, using the regular expression given in /pattern/, so the separators may be of any size and need not be the same string on every match. (The separators are not ordinarily returned; exceptions are discussed later in this section.) If the /pattern/ doesn't match the string at all, Ehebrew::split returns the original string as a single substring, If it matches once, you get two substrings, and so on. You may supply regular expression modifiers to the /pattern/, like /pattern/i, /pattern/x, etc. The //m modifier is assumed when you split on the pattern /^/. If $limit is specified and positive, the subroutine splits into no more than that many fields (though it may split into fewer if it runs out of separators). If $limit is negative, it is treated as if an arbitrarily large $limit has been specified If $limit is omitted or zero, trailing null fields are stripped from the result (which potential users of pop would do wel to remember). If $string is omitted, the subroutine splits the $_ string. If /pattern/ is also omitted or is the literal space, " ", the subroutine split on whitespace, /\s+/, after skipping any leading whitespace. A /pattern/ of /^/ is secretly treated if it it were /^/m, since it isn't much use otherwise. String of any length can be split: @chars = Ehebrew::split(//, $word); @fields = Ehebrew::split(/:/, $line); @words = Ehebrew::split(" ", $paragraph); @lines = Ehebrew::split(/^/, $buffer); A pattern capable of matching either the null string or something longer than the null string (for instance, a pattern consisting of any single character modified by a * or ?) will split the value of $string into separate characters wherever it matches the null string between characters; nonnull matches will skip over the matched separator characters in the usual fashion. (In other words, a pattern won't match in one spot more than once, even if it matched with a zero width.) For example: print join(":" => Ehebrew::split(/ */, "hi there")); produces the output "h:i:t:h:e:r:e". The space disappers because it matches as part of the separator. As a trivial case, the null pattern // simply splits into separate characters, and spaces do not disappear. (For normal pattern matches, a // pattern would repeat the last successfully matched pattern, but Ehebrew::split's pattern is exempt from that wrinkle.) The $limit parameter splits only part of a string: my ($login, $passwd, $remainder) = Ehebrew::split(/:/, $_, 3); We encourage you to split to lists of names like this to make your code self-documenting. (For purposes of error checking, note that $remainder would be undefined if there were fewer than three fields.) When assigning to a list, if $limit is omitted, Perl supplies a $limit one larger than the number of variables in the list, to avoid unneccessary work. For the split above, $limit would have been 4 by default, and $remainder would have received only the third field, not all the rest of the fields. In time-critical applications, it behooves you not to split into more fields than you really need. (The trouble with powerful languages it that they let you be powerfully stupid at times.) We said earlier that the separators are not returned, but if the /pattern/ contains parentheses, then the substring matched by each pair of parentheses is included in the resulting list, interspersed with the fields that are ordinarily returned. Here's a simple example: Ehebrew::split(/([-,])/, "1-10,20"); which produces the list value: (1, "-", 10, ",", 20) With more parentheses, a field is returned for each pair, even if some pairs don't match, in which case undefined values are returned in those positions. So if you say: Ehebrew::split(/(-)|(,)/, "1-10,20"); you get the value: (1, "-", undef, 10, undef, ",", 20) The /pattern/ argument may be replaced with an expression to specify patterns that vary at runtime. As with ordinary patterns, to do run-time compilation only once, use /$variable/o. As a special case, if the expression is a single space (" "), the subroutine splits on whitespace just as Ehebrew::split with no arguments does. Thus, Ehebrew::split(" ") can be used to emulate awk's default behavior. In contrast, Ehebrew::split(/ /) will give you as many null initial fields as there are leading spaces. (Other than this special case, if you supply a string instead of a regular expression, it'll be interpreted as a regular expression anyway.) You can use this property to remove leading and trailing whitespace from a string and to collapse intervaning stretches of whitespace into a single space: $string = join(" ", Ehebrew::split(" ", $string)); The following example splits an RFC822 message header into a hash containing $head{'Date'}, $head{'Subject'}, and so on. It uses the trick of assigning a list of pairs to a hash, because separators altinate with separated fields, It users parentheses to return part of each separator as part of the returned list value. Since the split pattern is guaranteed to return things in pairs by virtue of containing one set of parentheses, the hash assignment is guaranteed to receive a list consisting of key/value pairs, where each key is the name of a header field. (Unfortunately, this technique loses information for multiple lines with the same key field, such as Received-By lines. Ah well) $header =~ s/\n\s+/ /g; # Merge continuation lines. %head = ("FRONTSTUFF", Ehebrew::split(/^(\S*?):\s*/m, $header)); The following example processes the entries in a Unix passwd(5) file. You could leave out the chomp, in which case $shell would have a newline on the end of it. open(PASSWD, "/etc/passwd"); while (<PASSWD>) { chomp; # remove trailing newline. ($login, $passwd, $uid, $gid, $gcos, $home, $shell) = Ehebrew::split(/:/); ... } Here's how process each word of each line of each file of input to create a word-frequency hash. while (<>) { for my $word (Ehebrew::split()) { $count{$word}++; } } The inverse of Ehebrew::split is join, except that join can only join with the same separator between all fields. To break apart a string with fixed-position fields, use unpack. Processing long $string (over 32766 octets) requires Perl 5.010001 or later.
Transliteration
$tr = Ehebrew::tr($variable,$bind_operator,$searchlist,$replacementlist,$modifier); $tr = Ehebrew::tr($variable,$bind_operator,$searchlist,$replacementlist); This is the transliteration (sometimes erroneously called translation) operator, which is like the y/// operator in the Unix sed program, only better, in everybody's humble opinion. This subroutine scans a Hebrew string character by character and replaces all occurrences of the characters found in $searchlist with the corresponding character in $replacementlist. It returns the number of characters replaced or deleted. If no Hebrew string is specified via =~ operator, the $_ variable is translated. $modifier are: --------------------------------------------------------------------------- Modifier Meaning --------------------------------------------------------------------------- c Complement $searchlist. d Delete found but unreplaced characters. s Squash duplicate replaced characters. r Return transliteration and leave the original string untouched. --------------------------------------------------------------------------- To use with a read-only value without raising an exception, use the /r modifier. print Ehebrew::tr('bookkeeper','=~','boep','peob','r'); # prints 'peekkoobor'
Chop string
$chop = Ehebrew::chop(@list); $chop = Ehebrew::chop(); $chop = Ehebrew::chop; This subroutine chops off the last character of a string variable and returns the character chopped. The Ehebrew::chop subroutine is used primary to remove the newline from the end of an input recoed, and it is more efficient than using a substitution. If that's all you're doing, then it would be safer to use chomp, since Ehebrew::chop always shortens the string no matter what's there, and chomp is more selective. If no argument is given, the subroutine chops the $_ variable. You cannot Ehebrew::chop a literal, only a variable. If you Ehebrew::chop a list of variables, each string in the list is chopped: @lines = `cat myfile`; Ehebrew::chop(@lines); You can Ehebrew::chop anything that is an lvalue, including an assignment: Ehebrew::chop($cwd = `pwd`); Ehebrew::chop($answer = <STDIN>); This is different from: $answer = Ehebrew::chop($tmp = <STDIN>); # WRONG which puts a newline into $answer because Ehebrew::chop returns the character chopped, not the remaining string (which is in $tmp). One way to get the result intended here is with substr: $answer = substr <STDIN>, 0, -1; But this is more commonly written as: Ehebrew::chop($answer = <STDIN>); In the most general case, Ehebrew::chop can be expressed using substr: $last_code = Ehebrew::chop($var); $last_code = substr($var, -1, 1, ""); # same thing Once you understand this equivalence, you can use it to do bigger chops. To Ehebrew::chop more than one character, use substr as an lvalue, assigning a null string. The following removes the last five characters of $caravan: substr($caravan, -5) = ''; The negative subscript causes substr to count from the end of the string instead of the beginning. To save the removed characters, you could use the four-argument form of substr, creating something of a quintuple Ehebrew::chop; $tail = substr($caravan, -5, 5, ''); This is all dangerous business dealing with characters instead of graphemes. Perl doesn't really have a grapheme mode, so you have to deal with them yourself.
Index string
$byte_pos = Ehebrew::index($string,$substr,$byte_offset); $byte_pos = Ehebrew::index($string,$substr); This subroutine searches for one string within another. It returns the byte position of the first occurrence of $substring in $string. The $byte_offset, if specified, says how many bytes from the start to skip before beginning to look. Positions are based at 0. If the substring is not found, the subroutine returns one less than the base, ordinarily -1. To work your way through a string, you might say: $byte_pos = -1; while (($byte_pos = Ehebrew::index($string, $lookfor, $byte_pos)) > -1) { print "Found at $byte_pos\n"; $byte_pos++; }
Reverse index string
$byte_pos = Ehebrew::rindex($string,$substr,$byte_offset); $byte_pos = Ehebrew::rindex($string,$substr); This subroutine works just like Ehebrew::index except that it returns the byte position of the last occurrence of $substring in $string (a reverse Ehebrew::index). The subroutine returns -1 if $substring is not found. $byte_offset, if specified, is the rightmost byte position that may be returned. To work your way through a string backward, say: $byte_pos = length($string); while (($byte_pos = Hebrew::rindex($string, $lookfor, $byte_pos)) >= 0) { print "Found at $byte_pos\n"; $byte_pos--; }
Lower case string
$lc = Ehebrew::lc($string); $lc = Ehebrew::lc_; This subroutine returns a lowercased version of Hebrew $string (or $_, if $string is omitted). This is the internal subroutine implementing the \L escape in double-quoted strings. You can use the Ehebrew::fc subroutine for case-insensitive comparisons via Hebrew software.
Lower case first character of string
$lcfirst = Ehebrew::lcfirst($string); $lcfirst = Ehebrew::lcfirst_; This subroutine returns a version of Hebrew $string with the first character lowercased (or $_, if $string is omitted). This is the internal subroutine implementing the \l escape in double-quoted strings.
Upper case string
$uc = Ehebrew::uc($string); $uc = Ehebrew::uc_; This subroutine returns an uppercased version of Hebrew $string (or $_, if $string is omitted). This is the internal subroutine implementing the \U escape in interpolated strings. For titlecase, use Ehebrew::ucfirst instead. You can use the Ehebrew::fc subroutine for case-insensitive comparisons via Hebrew software.
Upper case first character of string
$ucfirst = Ehebrew::ucfirst($string); $ucfirst = Ehebrew::ucfirst_; This subroutine returns a version of Hebrew $string with the first character titlecased and other characters left alone (or $_, if $string is omitted). Titlecase is "Camel" for an initial capital that has (or expects to have) lowercase characters following it, not uppercase ones. Exsamples are the first letter of a sentence, of a person's name, of a newspaper headline, or of most words in a title. Characters with no titlecase mapping return the uppercase mapping instead. This is the internal subroutine implementing the \u escape in double-quoted strings. To capitalize a string by mapping its first character to titlecase and the rest to lowercase, use: $titlecase = Ehebrew::ucfirst(substr($word,0,1)) . Ehebrew::lc(substr($word,1)); or $string =~ s/(\w)((?>\w*))/\u$1\L$2/g; Do not use: $do_not_use = Ehebrew::ucfirst(Ehebrew::lc($word)); or "\u\L$word", because that can produce a different and incorrect answer with certain characters. The titlecase of something that's been lowercased doesn't always produce the same thing titlecasing the original produces. Because titlecasing only makes sense at the start of a string that's followed by lowercase characters, we can't think of any reason you might want to titlecase every character in a string. See also P.287 A Case of Mistaken Identity in Chapter 6: Unicode of ISBN 978-0-596-00492-7 Programming Perl 4th Edition.
Fold case string
P.860 fc in Chapter 27: Functions of ISBN 978-0-596-00492-7 Programming Perl 4th Edition. $fc = Ehebrew::fc($string); $fc = Ehebrew::fc_; New to Hebrew software, this subroutine returns the full Unicode-like casefold of Hebrew $string (or $_, if omitted). This is the internal subroutine implementing the \F escape in double-quoted strings. Just as title-case is based on uppercase but different, foldcase is based on lowercase but different. In ASCII there is a one-to-one mapping between only two cases, but in other encoding there is a one-to-many mapping and between three cases. Because that's too many combinations to check manually each time, a fourth casemap called foldcase was invented as a common intermediary for the other three. It is not a case itself, but it is a casemap. To compare whether two strings are the same without regard to case, do this: Ehebrew::fc($a) eq Ehebrew::fc($b) The reliable way to compare string case-insensitively was with the /i pattern modifier, because Hebrew software has always used casefolding semantics for case-insensitive pattern matches. Knowing this, you can emulate equality comparisons like this: sub fc_eq ($$) { my($a,$b) = @_; return $a =~ /\A\Q$b\E\z/i; }
Make ignore case string
@ignorecase = Ehebrew::ignorecase(@string); This subroutine is internal use to m/ /i, s/ / /i, split / /i, and qr/ /i.
Make capture number
$capturenumber = Ehebrew::capture($string); This subroutine is internal use to m/ /, s/ / /, split / /, and qr/ /.
Make character
$chr = Ehebrew::chr($code); $chr = Ehebrew::chr_; This subroutine returns a programmer-visible character, character represented by that $code in the character set. For example, Ehebrew::chr(65) is "A" in either ASCII or Hebrew, not Unicode. For the reverse of Ehebrew::chr, use Hebrew::ord.
Filename expansion (globbing)
@glob = Ehebrew::glob($string); @glob = Ehebrew::glob_; This subroutine returns the value of $string with filename expansions the way a DOS-like shell would expand them, returning the next successive name on each call. If $string is omitted, $_ is globbed instead. This is the internal subroutine implementing the <*> and glob operator. This subroutine function when the pathname ends with chr(0x5C) on MSWin32. For ease of use, the algorithm matches the DOS-like shell's style of expansion, not the UNIX-like shell's. An asterisk ("*") matches any sequence of any character (including none). A question mark ("?") matches any one character or none. A tilde ("~") expands to a home directory, as in "~/.*rc" for all the current user's "rc" files, or "~jane/Mail/*" for all of Jane's mail files. Note that all path components are case-insensitive, and that backslashes and forward slashes are both accepted, and preserved. You may have to double the backslashes if you are putting them in literally, due to double-quotish parsing of the pattern by perl. The Ehebrew::glob subroutine grandfathers the use of whitespace to separate multiple patterns such as <*.c *.h>. If you want to glob filenames that might contain whitespace, you'll have to use extra quotes around the spacy filename to protect it. For example, to glob filenames that have an "e" followed by a space followed by an "f", use either of: @spacies = <"*e f*">; @spacies = Ehebrew::glob('"*e f*"'); @spacies = Ehebrew::glob(q("*e f*")); If you had to get a variable through, you could do this: @spacies = Ehebrew::glob("'*${var}e f*'"); @spacies = Ehebrew::glob(qq("*${var}e f*")); Another way on MSWin32 # relative path @relpath_file = split(/\n/,`dir /b wildcard\\here*.txt 2>NUL`); # absolute path @abspath_file = split(/\n/,`dir /s /b wildcard\\here*.txt 2>NUL`); # on COMMAND.COM @relpath_file = split(/\n/,`dir /b wildcard\\here*.txt`); @abspath_file = split(/\n/,`dir /s /b wildcard\\here*.txt`);