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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409
|
package Perl6::Slurp;
use 5.008;
use Perl6::Export;
use Carp;
use warnings;
our $VERSION = '0.03';
my $mode_pat = qr{
^ \s* ( (?: < | \+< | \+>>? ) &? ) \s*
}x;
my $mode_plus_layers = qr{
(?: $mode_pat | ^ \s* -\| \s* )
( (?: :[^\W\d]\w* \s* )* )
\s*
\z
}x;
sub slurp is export(:DEFAULT) {
my $list_context = wantarray;
my $default = $_;
croak "Useless use of &slurp in a void context"
unless defined $list_context;
my @layers;
for (my $i=0; $i<@_; $i++) {
my $type = ref $_[$i] or next;
if ($type eq 'HASH') {
push @layers, splice @_, $i--, 1
}
elsif ($type eq 'ARRAY') {
my @array = @{splice @_, $i--, 1};
while (@array) {
my ($layer, $value) = splice @array, 0, 2;
croak "Incomplete layer specification for :$layer",
"\n(did you mean: $layer=>1)\n "
unless $value;
push @layers, { $layer=>$value };
}
}
}
my ($mode, $source, @args) = @_;
$mode = defined $default ? $default
: @ARGV ? \*ARGV
: "-"
unless defined $mode;
if (ref $mode) {
$source = $mode;
$mode = "<";
}
elsif ($mode !~ /$mode_plus_layers/x) {
$source = $mode;
$mode = $source =~ s/$mode_pat//x ? "$1"
: $source =~ s/ \| \s* $//x ? "-|"
: "<"
;
}
my $ref = ref $source;
if ($ref) {
croak "Can't use $ref as a data source"
unless $ref eq 'SCALAR'
|| $ref eq 'GLOB'
|| UNIVERSAL::isa($source, 'IO::Handle');
}
local $/ = "\n";
my ($chomp, $chomp_to, $layers) = (0, "", "");
for (@layers) {
if (exists $_->{irs}) {
$/ = $_->{irs};
delete $_->{irs};
}
if (exists $_->{chomp}) {
$chomp = 1;
$chomp_to = $_->{chomp}
if defined $_->{chomp} && $_->{chomp} ne "1";
delete $_->{chomp};
}
$layers .= join " ", map ":$_", keys %$_;
}
$mode .= " $layers";
my $FH;
if ($ref && $ref ne 'SCALAR') {
$FH = $source;
}
else {
open $FH, $mode, $source, @args or croak "Can't open '$source': $!";
}
my $chomp_into = ref $chomp_to eq 'CODE' ? $chomp_to : sub{ $chomp_to };
my $data = $FH == \*ARGV ? join("",<>) : do { local $/; <$FH> };
my $irs = ref($/) ? $/
: defined($/) ? qr{\Q$/\E}
: qr{(?!)};
if ($list_context) {
return () unless defined $data;
my @lines = split /($irs)/, $data;
my $reps = @lines/2-1;
$reps = -1 if $reps<0;
for my $i (0..$reps) {
my $sep = splice @lines, $i+1, 1;
$sep = $chomp_into->($sep) if $chomp;
$lines[$i] .= $sep if defined $sep;
}
return @lines;
}
else {
return "" unless defined $data;
$data =~ s{($irs)}{$chomp_into->($1)}ge if $chomp;
return $data;
}
}
1;
__END__
=head1 NAME
Perl6::Slurp - Implements the Perl 6 'slurp' built-in
=head1 SYNOPSIS
use Perl6::Slurp;
# Slurp a file by name...
$file_contents = slurp 'filename';
$file_contents = slurp '<filename';
$file_contents = slurp '<', 'filename';
$file_contents = slurp '+<', 'filename';
# Slurp a file via an (already open!) handle...
$file_contents = slurp \*STDIN;
$file_contents = slurp $filehandle;
$file_contents = slurp IO::File->new('filename');
# Slurp a string...
$str_contents = slurp \$string;
$str_contents = slurp '<', \$string;
# Slurp a pipe...
$str_contents = slurp 'tail -20 $filename |';
$str_contents = slurp '-|', 'tail', -20, $filename;
# Slurp with no source slurps from whatever $_ indicates...
for (@files) {
$contents .= slurp;
}
# ...or from the entire ARGV list, if $_ is undefined...
$_ = undef;
$ARGV_contents = slurp;
# Specify I/O layers as part of mode...
$file_contents = slurp '<:raw', $file;
$file_contents = slurp '<:utf8', $file;
$file_contents = slurp '<:raw :utf8', $file;
# Specify I/O layers as separate options...
$file_contents = slurp $file, {raw=>1};
$file_contents = slurp $file, {utf8=>1};
$file_contents = slurp $file, {raw=>1}, {utf8=>1};
$file_contents = slurp $file, [raw=>1, utf8=>1];
# Specify input record separator...
$file_contents = slurp $file, {irs=>"\n\n"};
$file_contents = slurp '<', $file, {irs=>"\n\n"};
$file_contents = slurp {irs=>"\n\n"}, $file;
# Input record separator can be regex...
$file_contents = slurp $file, {irs=>qr/\n+/};
$file_contents = slurp '<', $file, {irs=>qr/\n+|\t{2,}};
# Specify autochomping...
$file_contents = slurp $file, {chomp=>1};
$file_contents = slurp {chomp=>1}, $file;
$file_contents = slurp $file, {chomp=>1, irs=>"\n\n"};
$file_contents = slurp $file, {chomp=>1, irs=>qr/\n+/};
# Specify autochomping that replaces irs
# with another string...
$file_contents = slurp $file, {irs=>"\n\n", chomp=>"\n"};
$file_contents = slurp $file, {chomp=>"\n\n"}, {irs=>qr/\n+/};
# Specify autochomping that replaces
# irs with a dynamically computed string...
my $n = 1;
$file_contents = slurp $file, {chomp=>sub{ "\n#line ".$n++."\n"};
# Slurp in a list context...
@lines = slurp 'filename';
@lines = slurp $filehandle;
@lines = slurp \$string;
@lines = slurp '<:utf8', 'filename', {irs=>"\x{2020}", chomp=>"\n"};
=head1 DESCRIPTION
C<slurp> takes:
=over
=item *
a filename,
=item *
a filehandle,
=item *
a typeglob reference,
=item *
an IO::File object, or
=item *
a scalar reference,
=back
converts it to an input stream if necessary, and reads in the entire stream.
If C<slurp> fails to set up or read the stream, it throws an exception.
If no data source is specified C<slurp> uses the value of C<$_> as the
source. If C<$_> is undefined, C<slurp> uses the C<@ARGV> list,
and magically slurps the contents of I<all> the sources listed in C<@ARGV>.
Note that the same magic is also applied if you explicitly slurp <*ARGV>, so
the following three input operations:
$contents = join "", <ARGV>;
$contents = slurp \*ARGV;
$/ = undef;
$contents = slurp;
are identical in effect.
In a scalar context C<slurp> returns the stream contents as a single string.
If the stream is at EOF, it returns an empty string.
In a list context, it splits the contents after the appropriate input
record separator and returns the resulting list of strings.
You can set the input record separator (S<< C<< { irs => $your_irs_here}
>> >>) for the input operation. The separator can be specified as a
string or a regex. Note that an explicit input record separator has no
effect in a scalar context, since C<slurp> always reads in everything anyway.
In a list context, changing the separator can change how the input is
broken up within the list that is returned.
If an input record separator is not explicitly specified, C<slurp>
defaults to C<"\n"> (I<not> to the current value of C<$/> E<ndash> since
Perl 6 doesn't I<have> a C<$/>);
You can also tell C<slurp> to automagically C<chomp> the input as it is
read in, by specifying: (S<< C<< { chomp => 1 } >> >>)
Better still, you can tell C<slurp> to automagically
C<chomp> the input and I<replace> what it chomps with another string,
by specifying: (S<< C<< { chomp => "another string" } >> >>)
You can also tell C<slurp> to compute the replacement string on-the-fly
by specifying a subroutine as the C<chomp> value:
(S<< C<< { chomp => sub{...} } >> >>). This subroutine is passed the string
being chomped off, so for example you could squeeze single newlines to a
single space and multiple conseqcutive newlines to a two newlines with:
sub squeeze {
my ($removed) = @_;
if ($removed =~ tr/\n/\n/ == 1) { return " " }
else { return "\n\n"; }
}
print slurp(\*DATA, {irs=>qr/[ \t]*\n+/, chomp=>\&squeeze}), "\n";
Which would transform:
This is the
first paragraph
This is the
second
paragraph
This, the
third
This one is
the
very
last
to:
This is the first paragraph
This is the second paragraph
This, the third
This one is the very last
Autochomping works in both scalar and list contexts. In scalar contexts every
instance of the input record separator will be removed (or replaced) within
the returned string. In list context, each list item returned with its
terminating separator removed (or replaced).
You can specify I/O layers, either using the Perl 5 notation:
slurp "<:layer1 :layer2 :etc", $filename;
or as an array of options:
slurp $filename, [layer1=>1, layer2=>1, etc=>1];
slurp [layer1=>1, layer2=>1, etc=>1], $filename;
or as individual options (each of which must be in a separate hash):
slurp $filename, {layer1=>1}, {layer2=>1}, {etc=>1};
slurp {layer1=>1}, {layer2=>1}, {etc=>1}, $filename;
(...which, of course, would look much cooler in Perl 6:
# Perl 6 only :-(
slurp $filename, :layer1 :layer2 :etc;
slurp :layer1 :layer2 :etc, $filename;
)
A common mistake is to put all the options together in one hash:
slurp $filename, {layer1=>1, layer2=>1, etc=>1};
This is almost always a disaster, since the order of I/O layers is usually
critical, and placing them all in one hash effectively randomizes that order.
Use an array instead:
slurp $filename, [layer1=>1, layer2=>1, etc=>1];
=head1 WARNING
The syntax and semantics of Perl 6 is still being finalized
and consequently is at any time subject to change. That means the
same caveat applies to this module.
=head1 DEPENDENCIES
Requires: Perl 5.8.0, Perl6::Export
=head1 AUTHOR
Damian Conway (damian@conway.org)
=head1 COPYRIGHT
Copyright (c) 2003, Damian Conway. All Rights Reserved.
This module is free software. It may be used, redistributed
and/or modified under the same terms as Perl itself.
|