summaryrefslogtreecommitdiff
path: root/Master/tlpkg/tlperl/lib/English.pm
blob: 283cd010701aae04accfee82e5968a092b3c0a24 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
package English;

our $VERSION = '1.11';

require Exporter;
@ISA = qw(Exporter);

=head1 NAME

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

=head1 SYNOPSIS

    use English;
    use English qw( -no_match_vars ) ;  # Avoids regex performance
                                        # penalty in perl 5.18 and
                                        # earlier
    ...
    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

NOTE: This was fixed in perl 5.20.  Mentioning these three variables no
longer makes a speed difference.  This section still applies if your code
is to run on perl 5.18 or earlier.

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
	*OLD_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					= *_	;

# 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			= *-{SCALAR}	;
	*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	;
	*OLD_PERL_VERSION			= *]	;
	*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					= *#	;

1;