package English;

our $VERSION = '1.04';

require Exporter;
@ISA = qw(Exporter);

=head1 NAME

English - use nice English (or awk) names for ugly punctuation variables

=head1 SYNOPSIS

use English qw( -no_match_vars ) ; # Avoids regex performance penalty
use English;
...
if ($ERRNO =~ /denied/) { ... }

=head1 DESCRIPTION

This module provides aliases for the built-in variables whose
names no one seems to like to read. Variables with side-effects
which get triggered just by accessing them (like $0) will still
be affected.

For those variables that have an B<awk> version, both long
and short English alternatives are provided. For example,
the C<$/> variable can be referred to either $RS or
$INPUT_RECORD_SEPARATOR if you are using the English module.

See L<perlvar> for a complete list of these.

=head1 PERFORMANCE

This module can provoke sizeable inefficiencies for regular expressions,
due to unfortunate implementation details. If performance matters in
your application and you don't need $PREMATCH, $MATCH, or $POSTMATCH,
try doing

use English qw( -no_match_vars ) ;

. B<It is especially important to do this in modules to avoid penalizing
all applications which use them.>

=cut

no warnings;

my $globbed_match ;

# Grandfather $NAME import
sub import {
my $this = shift;
my @list = grep { ! /^-no_match_vars$/ } @_ ;
local $Exporter::ExportLevel = 1;
if ( @_ == @list ) {
*EXPORT = \@COMPLETE_EXPORT ;
$globbed_match ||= (
eval q{
*MATCH = *& ;
*PREMATCH = *` ;
*POSTMATCH = *' ;
1 ;
}
|| do {
require Carp ;
Carp::croak("Can't create English for match leftovers: $@") ;
}
) ;
}
else {
*EXPORT = \@MINIMAL_EXPORT ;
}
Exporter::import($this,grep {s/^\$/*/} @list);
}

@MINIMAL_EXPORT = qw(
*ARG
*LAST_PAREN_MATCH
*INPUT_LINE_NUMBER
*NR
*INPUT_RECORD_SEPARATOR
*RS
*OUTPUT_AUTOFLUSH
*OUTPUT_FIELD_SEPARATOR
*OFS
*OUTPUT_RECORD_SEPARATOR
*ORS
*LIST_SEPARATOR
*SUBSCRIPT_SEPARATOR
*SUBSEP
*FORMAT_PAGE_NUMBER
*FORMAT_LINES_PER_PAGE
*FORMAT_LINES_LEFT
*FORMAT_NAME
*FORMAT_TOP_NAME
*FORMAT_LINE_BREAK_CHARACTERS
*FORMAT_FORMFEED
*CHILD_ERROR
*OS_ERROR
*ERRNO
*EXTENDED_OS_ERROR
*EVAL_ERROR
*PROCESS_ID
*PID
*REAL_USER_ID
*UID
*EFFECTIVE_USER_ID
*EUID
*REAL_GROUP_ID
*GID
*EFFECTIVE_GROUP_ID
*EGID
*PROGRAM_NAME
*PERL_VERSION
*ACCUMULATOR
*COMPILING
*DEBUGGING
*SYSTEM_FD_MAX
*INPLACE_EDIT
*PERLDB
*BASETIME
*WARNING
*EXECUTABLE_NAME
*OSNAME
*LAST_REGEXP_CODE_RESULT
*EXCEPTIONS_BEING_CAUGHT
*LAST_SUBMATCH_RESULT
@LAST_MATCH_START
@LAST_MATCH_END
);


@MATCH_EXPORT = qw(
*MATCH
*PREMATCH
*POSTMATCH
);

@COMPLETE_EXPORT = ( @MINIMAL_EXPORT, @MATCH_EXPORT ) ;

# The ground of all being. @ARG is deprecated (5.005 makes @_ lexical)

*ARG = *_ ;

# Matching.

*LAST_PAREN_MATCH = *+ ;
*LAST_SUBMATCH_RESULT = *^N ;
*LAST_MATCH_START = *-{ARRAY} ;
*LAST_MATCH_END = *+{ARRAY} ;

# Input.

*INPUT_LINE_NUMBER = *. ;
*NR = *. ;
*INPUT_RECORD_SEPARATOR = */ ;
*RS = */ ;

# Output.

*OUTPUT_AUTOFLUSH = *| ;
*OUTPUT_FIELD_SEPARATOR = *, ;
*OFS = *, ;
*OUTPUT_RECORD_SEPARATOR = *\ ;
*ORS = *\ ;

# Interpolation "constants".

*LIST_SEPARATOR = *" ;
*SUBSCRIPT_SEPARATOR = *; ;
*SUBSEP = *; ;

# Formats

*FORMAT_PAGE_NUMBER = *% ;
*FORMAT_LINES_PER_PAGE = *= ;
*FORMAT_LINES_LEFT = *- ;
*FORMAT_NAME = *~ ;
*FORMAT_TOP_NAME = *^ ;
*FORMAT_LINE_BREAK_CHARACTERS = *: ;
*FORMAT_FORMFEED = *^L ;

# Error status.

*CHILD_ERROR = *? ;
*OS_ERROR = *! ;
*ERRNO = *! ;
*OS_ERROR = *! ;
*ERRNO = *! ;
*EXTENDED_OS_ERROR = *^E ;
*EVAL_ERROR = *@ ;

# Process info.

*PROCESS_ID = *$ ;
*PID = *$ ;
*REAL_USER_ID = *< ;
*UID = *< ;
*EFFECTIVE_USER_ID = *> ;
*EUID = *> ;
*REAL_GROUP_ID = *( ;
*GID = *( ;
*EFFECTIVE_GROUP_ID = *) ;
*EGID = *) ;
*PROGRAM_NAME = *0 ;

# Internals.

*PERL_VERSION = *^V ;
*ACCUMULATOR = *^A ;
*COMPILING = *^C ;
*DEBUGGING = *^D ;
*SYSTEM_FD_MAX = *^F ;
*INPLACE_EDIT = *^I ;
*PERLDB = *^P ;
*LAST_REGEXP_CODE_RESULT = *^R ;
*EXCEPTIONS_BEING_CAUGHT = *^S ;
*BASETIME = *^T ;
*WARNING = *^W ;
*EXECUTABLE_NAME = *^X ;
*OSNAME = *^O ;

# Deprecated.

# *ARRAY_BASE = *[ ;
# *OFMT = *# ;
# *OLD_PERL_VERSION = *] ;

1;