Bio/Tools/GuessSeqFormat.pm

   1 #------------------------------------------------------------------
   2 #
   3 # BioPerl module Bio::Tools::GuessSeqFormat
   4 #
   5 # Please direct questions and support issues to <bioperl-l@bioperl.org>
   6 #
   7 # Cared for by Andreas Kähäri, andreas.kahari@ebi.ac.uk
   8 #
   9 # You may distribute this module under the same terms as perl itself
  10 #------------------------------------------------------------------
  11
  12 =encoding utf-8
  13
  14 =head1 NAME
  15
  16 Bio::Tools::GuessSeqFormat - Module for determining the sequence
  17 format of the contents of a file, a string, or through a
  18 filehandle.
  19
  20 =head1 SYNOPSIS
  21
  22     # To guess the format of a flat file, given a filename:
  23     my $guesser = Bio::Tools::GuessSeqFormat->new( -file => $filename );
  24     my $format  = $guesser->guess;
  25
  26     # To guess the format from an already open filehandle:
  27     my $guesser = Bio::Tools::GuessSeqFormat->new( -fh => $filehandle );
  28     my $format  = $guesser->guess;
  29     # The filehandle will be returned to its original position. Note that this
  30     # filehandle can be STDIN.
  31
  32     # To guess the format of one or several lines of text (with
  33     # embedded newlines):
  34     my $guesser = Bio::Tools::GuessSeqFormat->new( -text => $linesoftext );
  35     my $format = $guesser->guess;
  36
  37     # To create a Bio::Tools::GuessSeqFormat object and set the
  38     # filename, filehandle, or line to parse afterwards:
  39     my $guesser = Bio::Tools::GuessSeqFormat->new();
  40     $guesser->file($filename);
  41     $guesser->fh($filehandle);
  42     $guesser->text($linesoftext);
  43
  44     # To guess in one go, given e.g. a filename:
  45     my $format = Bio::Tools::GuessSeqFormat->new( -file => $filename )->guess;
  46
  47 =head1 DESCRIPTION
  48
  49 Bio::Tools::GuessSeqFormat tries to guess the format ("swiss",
  50 "pir", "fasta" etc.) of the sequence or MSA in a file, in a
  51 scalar, or through a filehandle.
  52
  53 The guess() method of a Bio::Tools::GuessSeqFormat object will
  54 examine the data, line by line, until it finds a line to which
  55 only one format can be assigned.  If no conclusive guess can be
  56 made, undef is returned.
  57
  58 If the Bio::Tools::GuessSeqFormat object is given a filehandle,
  59 e.g. STDIN, it will be restored to its original position on
  60 return from the guess() method.
  61
  62 =head2 Formats
  63
  64 Tests are currently implemented for the following formats:
  65
  66 =over
  67
  68 =item *
  69
  70 ACeDB ("ace")
  71
  72 =item *
  73
  74 Blast ("blast")
  75
  76 =item *
  77
  78 ClustalW ("clustalw")
  79
  80 =item *
  81
  82 Codata ("codata")
  83
  84 =item *
  85
  86 EMBL ("embl")
  87
  88 =item *
  89
  90 FastA sequence ("fasta")
  91
  92 =item *
  93
  94 FastQ sequence ("fastq")
  95
  96 =item *
  97
  98 FastXY/FastA alignment ("fastxy")
  99
 100 =item *
 101
 102 Game XML ("game")
 103
 104 =item *
 105
 106 GCG ("gcg")
 107
 108 =item *
 109
 110 GCG Blast ("gcgblast")
 111
 112 =item *
 113
 114 GCG FastA ("gcgfasta")
 115
 116 =item *
 117
 118 GDE ("gde")
 119
 120 =item *
 121
 122 Genbank ("genbank")
 123
 124 =item *
 125
 126 Genscan ("genscan")
 127
 128 =item *
 129
 130 GFF ("gff")
 131
 132 =item *
 133
 134 HMMER ("hmmer")
 135
 136 =item *
 137
 138 PAUP/NEXUS ("nexus")
 139
 140 =item *
 141
 142 Phrap assembly file ("phrap")
 143
 144 =item *
 145
 146 NBRF/PIR ("pir")
 147
 148 =item *
 149
 150 Mase ("mase")
 151
 152 =item *
 153
 154 Mega ("mega")
 155
 156 =item *
 157
 158 GCG/MSF ("msf")
 159
 160 =item *
 161
 162 Pfam ("pfam")
 163
 164 =item *
 165
 166 Phylip ("phylip")
 167
 168 =item *
 169
 170 Prodom ("prodom")
 171
 172 =item *
 173
 174 Raw ("raw")
 175
 176 =item *
 177
 178 RSF ("rsf")
 179
 180 =item *
 181
 182 Selex ("selex")
 183
 184 =item *
 185
 186 Stockholm ("stockholm")
 187
 188 =item *
 189
 190 Swissprot ("swiss")
 191
 192 =item *
 193
 194 Tab ("tab")
 195
 196 =item *
 197
 198 Variant Call Format ("vcf")
 199
 200 =back
 201
 202 =head1 FEEDBACK
 203
 204 =head2 Mailing Lists
 205
 206 User feedback is an integral part of the evolution of this and
 207 other Bioperl modules.  Send your comments and suggestions
 208 preferably to one of the Bioperl mailing lists.  Your
 209 participation is much appreciated.
 210
 211   bioperl-l@bioperl.org                  - General discussion
 212   http://bioperl.org/wiki/Mailing_lists  - About the mailing lists
 213
 214 =head2 Support
 215
 216 Please direct usage questions or support issues to the mailing list:
 217
 218 I<bioperl-l@bioperl.org>
 219
 220 rather than to the module maintainer directly. Many experienced and
 221 reponsive experts will be able look at the problem and quickly
 222 address it. Please include a thorough description of the problem
 223 with code and data examples if at all possible.
 224
 225 =head2 Reporting Bugs
 226
 227 Report bugs to the Bioperl bug tracking system to help us
 228 keep track the bugs and their resolution.  Bug reports can be
 229 submitted via the web:
 230
 231   https://github.com/bioperl/bioperl-live/issues
 232
 233 =head1 AUTHOR
 234
 235 Andreas KE<228>hE<228>ri, andreas.kahari@ebi.ac.uk
 236
 237 =head1 CONTRIBUTORS
 238
 239 Heikki LehvE<228>slaiho, heikki-at-bioperl-dot-org
 240 Mark A. Jensen, maj-at-fortinbras-dot-us
 241
 242 =cut
 243
 244
 245 package Bio::Tools::GuessSeqFormat;
 246
 247 use strict;
 248 use warnings;
 249
 250
 251 use base qw(Bio::Root::Root);
 252
 253 =head1 METHODS
 254
 255 Methods available to Bio::Tools::GuessSeqFormat objects
 256 are described below.  Methods with names beginning with an
 257 underscore are considered to be internal.
 258
 259 =cut
 260
 261 =head2 new
 262
 263  Title      : new
 264  Usage      : $guesser = Bio::Tools::GuessSeqFormat->new( ... );
 265  Function   : Creates a new object.
 266  Example    : See SYNOPSIS.
 267  Returns    : A new object.
 268  Arguments  : -file The filename of the file whose format is to
 269                     be guessed, e.g. STDIN, or
 270               -fh   An already opened filehandle from which a text
 271                     stream may be read, or
 272               -text A scalar containing one or several lines of
 273                     text with embedded newlines.
 274
 275     If more than one of the above arguments are given, they
 276     are tested in the order -text, -file, -fh, and the first
 277     available argument will be used.
 278
 279 =cut
 280
 281 sub new
 282 {
 283     my $class = shift;
 284     my @args  = @_;
 285
 286     my $self = $class->SUPER::new(@args);
 287
 288     my $attr;
 289     my $value;
 290
 291     while (@args) {
 292         $attr = shift @args;
 293         $attr = lc $attr;
 294         $value = shift @args;
 295         $self->{$attr} = $value;
 296     }
 297
 298     return $self;
 299 }
 300
 301 =head2 file
 302
 303  Title      : file
 304  Usage      : $guesser->file($filename);
 305               $filename = $guesser->file;
 306  Function   : Gets or sets the current filename associated with
 307               an object.
 308  Returns    : The new filename.
 309  Arguments  : The filename of the file whose format is to be
 310               guessed.
 311
 312     A call to this method will clear the current filehandle and
 313     the current lines of text associated with the object.
 314
 315 =cut
 316
 317 sub file
 318 {
 319     # Sets and/or returns the filename to use.
 320     my $self = shift;
 321     my $file = shift;
 322
 323     if (defined $file) {
 324         # Set the active filename, and clear the filehandle and
 325         # text line, if present.
 326         $self->{-file} = $file;
 327         $self->{-fh} = $self->{-text} = undef;
 328     }
 329
 330     return $self->{-file};
 331 }
 332
 333 =head2 fh
 334
 335  Title      : fh
 336  Usage      : $guesser->fh($filehandle);
 337               $filehandle = $guesser->fh;
 338  Function   : Gets or sets the current filehandle associated with
 339               an object.
 340  Returns    : The new filehandle.
 341  Arguments  : An already opened filehandle from which a text
 342               stream may be read.
 343
 344     A call to this method will clear the current filename and
 345     the current lines of text associated with the object.
 346
 347 =cut
 348
 349 sub fh
 350 {
 351     # Sets and/or returns the filehandle to use.
 352     my $self = shift;
 353     my $fh = shift;
 354
 355     if (defined $fh) {
 356         # Set the active filehandle, and clear the filename and
 357         # text line, if present.
 358         $self->{-fh} = $fh;
 359         $self->{-file} = $self->{-text} = undef;
 360     }
 361
 362     return $self->{-fh};
 363 }
 364
 365
 366 =head2 text
 367
 368  Title      : text
 369  Usage      : $guesser->text($linesoftext);
 370               $linesofext = $guesser->text;
 371  Function   : Gets or sets the current text associated with an
 372               object.
 373  Returns    : The new lines of texts.
 374  Arguments  : A scalar containing one or several lines of text,
 375               including embedded newlines.
 376
 377     A call to this method will clear the current filename and
 378     the current filehandle associated with the object.
 379
 380 =cut
 381
 382 sub text
 383 {
 384     # Sets and/or returns the text lines to use.
 385     my $self = shift;
 386     my $text = shift;
 387
 388     if (defined $text) {
 389         # Set the active text lines, and clear the filehandle
 390         # and filename, if present.
 391         $self->{-text} = $text;
 392         $self->{-fh} = $self->{-file} = undef;
 393     }
 394
 395     return $self->{-text};
 396 }
 397
 398 =head2 guess
 399
 400  Title      : guess
 401  Usage      : $format = $guesser->guess;
 402               @format = $guesser->guess; # if given a line of text
 403  Function   : Guesses the format of the data accociated with the
 404               object.
 405  Returns    : A format string such as "swiss" or "pir".  If a
 406               format can not be found, undef is returned.
 407  Arguments  : None.
 408
 409     If the object is associated with a filehandle, the position
 410     of the filehandle will be returned to its original position
 411     before the method returns.
 412
 413 =cut
 414
 415 our %formats = (
 416     ace         => { test => \&_possibly_ace        },
 417     blast       => { test => \&_possibly_blast      },
 418     bowtie      => { test => \&_possibly_bowtie     },
 419     clustalw    => { test => \&_possibly_clustalw   },
 420     codata      => { test => \&_possibly_codata     },
 421     embl        => { test => \&_possibly_embl       },
 422     fasta       => { test => \&_possibly_fasta      },
 423     fastq       => { test => \&_possibly_fastq      },
 424     fastxy      => { test => \&_possibly_fastxy     },
 425     game        => { test => \&_possibly_game       },
 426     gcg         => { test => \&_possibly_gcg        },
 427     gcgblast    => { test => \&_possibly_gcgblast   },
 428     gcgfasta    => { test => \&_possibly_gcgfasta   },
 429     gde         => { test => \&_possibly_gde        },
 430     genbank     => { test => \&_possibly_genbank    },
 431     genscan     => { test => \&_possibly_genscan    },
 432     gff         => { test => \&_possibly_gff        },
 433     hmmer       => { test => \&_possibly_hmmer      },
 434     nexus       => { test => \&_possibly_nexus      },
 435     mase        => { test => \&_possibly_mase       },
 436     mega        => { test => \&_possibly_mega       },
 437     msf         => { test => \&_possibly_msf        },
 438     pfam        => { test => \&_possibly_pfam       },
 439     phrap       => { test => \&_possibly_phrap      },
 440     phylip      => { test => \&_possibly_phylip     },
 441     pir         => { test => \&_possibly_pir        },
 442     prodom      => { test => \&_possibly_prodom     },
 443     raw         => { test => \&_possibly_raw        },
 444     rsf         => { test => \&_possibly_rsf        },
 445     selex       => { test => \&_possibly_selex      },
 446     stockholm   => { test => \&_possibly_stockholm  },
 447     swiss       => { test => \&_possibly_swiss      },
 448     tab         => { test => \&_possibly_tab        },
 449     vcf         => { test => \&_possibly_vcf        },
 450 );
 451
 452 sub guess
 453 {
 454     my $self = shift;
 455
 456     while (my ($fmt_key) = each (%formats)) {
 457         $formats{$fmt_key}{fmt_string} = $fmt_key;
 458     }
 459
 460     my $fh;
 461     my $start_pos;
 462     if (defined $self->{-text}) {
 463         # Break the text into separate lines.
 464         my $text = $self->{-text};
 465         open $fh, '<', \$text or $self->throw("Could not read from string: $!");
 466
 467     } elsif (defined $self->{-file}) {
 468         # If given a filename, open the file.
 469         my $file = $self->{-file};
 470         open $fh, '<', $file or $self->throw("Could not read file '$file': $!");
 471
 472     } elsif (defined $self->{-fh}) {
 473         # If given a filehandle, get the current position in the stream.
 474         $fh = $self->{-fh};
 475         if (not seek $fh, 0, 1) { # seek to current position to determine seekability
 476             # Work around non-seekable filehandles if IO::Scalar is available
 477             # (adapted from http://www.perlmonks.org/?node_id=33587)
 478             # IO::Mark may be an option for very large streams?
 479             $self->throw("Need IO::Scalar to guess from unseekable filehandles")
 480                 if not eval { require IO::Scalar };
 481             my $data;
 482             { local $/; $data = <$fh>; $.-- };  # copy raw data from fh
 483             tie *$fh, 'IO::Scalar', my $s;      # replace fh by scalar-tied fh
 484             print $fh $data;                    # write raw data to tied fh
 485             seek $fh, 0, 0;                     # return to start of tied fh
 486         }
 487         $start_pos = tell $fh;
 488     }
 489
 490     my $done  = 0;
 491     my $lineno = 0;
 492     my $guess;
 493     while (!$done) {
 494         my $line;       # The next line of the file.
 495         my $match = 0;  # Number of possible formats of this line.
 496
 497         last if (!defined($line = <$fh>));
 498         next if ($line =~ /^\s*$/); # Skip white and empty lines.
 499         chomp $line;
 500         $line =~ s/\r$//;   # Fix for DOS files on Unix.
 501         ++$lineno;
 502
 503         while (my ($fmt_key, $fmt) = each (%formats)) {
 504             if ($fmt->{test}($line, $lineno)) {
 505                 ++$match;
 506                 $guess = $fmt->{fmt_string};
 507             }
 508         }
 509
 510         # We're done if there was only one match.
 511         $done = ($match == 1);
 512     }
 513
 514     if (defined $self->{-fh}) {
 515         # Go back to original position in filehandle
 516         seek $fh, $start_pos, 0 or $self->throw("Could not reset filehandle $fh: $!");
 517     } else {
 518         # Close the filehandle we opened
 519         close $fh;
 520     }
 521     return ($done ? $guess : undef);
 522 }
 523
 524 =head1 HELPER SUBROUTINES
 525
 526 All helper subroutines will, given a line of text and the line
 527 number of the same line, return 1 if the line possibly is from a
 528 file of the type that they perform a test of.
 529
 530 A zero return value does not mean that the line is not part
 531 of a certain type of file, just that the test did not find any
 532 characteristics of that type of file in the line.
 533
 534 =head2 _possibly_ace
 535
 536 From bioperl test data, and from
 537 "http://www.isrec.isb-sib.ch/DEA/module8/B_Stevenson/Practicals/transcriptome_recon/transcriptome_recon.html".
 538
 539 =cut
 540
 541 sub _possibly_ace
 542 {
 543     my ($line, $lineno) = (shift, shift);
 544     return ($line =~ /^(?:Sequence|Peptide|DNA|Protein) [":]/);
 545 }
 546
 547 =head2 _possibly_blast
 548
 549  From various blast results.
 550
 551 =cut
 552
 553 sub _possibly_blast
 554 {
 555     my ($line, $lineno) = (shift, shift);
 556     return ($lineno == 1 &&
 557         $line =~ /^[[:upper:]]*BLAST[[:upper:]]*.*\[.*\]$/);
 558 }
 559
 560 =head2 _possibly_bowtie
 561
 562 Contributed by kortsch.
 563
 564 =cut
 565
 566 sub _possibly_bowtie
 567 {
 568     my ($line, $lineno) = (shift, shift);
 569     return ($line =~ /^[[:graph:]]+\t[-+]\t[[:graph:]]+\t\d+\t([[:alpha:]]+)\t([[:graph:]]+)\t\d+\t[[:graph:]]?/)
 570             && length($1)==length($2);
 571 }
 572
 573 =head2 _possibly_clustalw
 574
 575 From "http://www.ebi.ac.uk/help/formats.html".
 576
 577 =cut
 578
 579 sub _possibly_clustalw
 580 {
 581     my ($line, $lineno) = (shift, shift);
 582     return ($lineno == 1 && $line =~ /CLUSTAL/);
 583 }
 584
 585 =head2 _possibly_codata
 586
 587 From "http://www.ebi.ac.uk/help/formats.html".
 588
 589 =cut
 590
 591 sub _possibly_codata
 592 {
 593     my ($line, $lineno) = (shift, shift);
 594     return (($lineno == 1 && $line =~ /^ENTRY/) ||
 595             ($lineno == 2 && $line =~ /^SEQUENCE/) ||
 596             $line =~ m{^(?:ENTRY|SEQUENCE|///)});
 597 }
 598
 599 =head2 _possibly_embl
 600
 601 From
 602 "http://www.ebi.ac.uk/embl/Documentation/User_manual/usrman.html#3.3".
 603
 604 =cut
 605
 606 sub _possibly_embl
 607 {
 608     my ($line, $lineno) = (shift, shift);
 609     return ($lineno == 1 && $line =~ /^ID   / && $line =~ /BP\.$/);
 610 }
 611
 612 =head2 _possibly_fasta
 613
 614 From "http://www.ebi.ac.uk/help/formats.html".
 615
 616 =cut
 617
 618 sub _possibly_fasta
 619 {
 620     my ($line, $lineno) = (shift, shift);
 621     return (($lineno != 1 && $line =~ /^[A-IK-NP-Z]+$/i) ||
 622             $line =~ /^>\s*\w/);
 623 }
 624
 625 =head2 _possibly_fastq
 626
 627 From bioperl test data.
 628
 629 =cut
 630
 631 sub _possibly_fastq
 632 {
 633     my ($line, $lineno) = (shift, shift);
 634     return ( ($lineno == 1 && $line =~ /^@/) ||
 635              ($lineno == 3 && $line =~ /^\+/) );
 636 }
 637
 638 =head2 _possibly_fastxy
 639
 640 From bioperl test data.
 641
 642 =cut
 643
 644 sub _possibly_fastxy
 645 {
 646     my ($line, $lineno) = (shift, shift);
 647     return (($lineno == 1 && $line =~ /^ FAST(?:XY|A)/) ||
 648             ($lineno == 2 && $line =~ /^ version \d/));
 649 }
 650
 651 =head2 _possibly_game
 652
 653 From bioperl testdata.
 654
 655 =cut
 656
 657 sub _possibly_game
 658 {
 659     my ($line, $lineno) = (shift, shift);
 660     return ($line =~ /^<!DOCTYPE game/);
 661 }
 662
 663 =head2 _possibly_gcg
 664
 665 From bioperl, Bio::SeqIO::gcg.
 666
 667 =cut
 668
 669 sub _possibly_gcg
 670 {
 671     my ($line, $lineno) = (shift, shift);
 672     return ($line =~ /Length: .*Type: .*Check: .*\.\.$/);
 673 }
 674
 675 =head2 _possibly_gcgblast
 676
 677 From bioperl testdata.
 678
 679 =cut
 680
 681 sub _possibly_gcgblast
 682 {
 683     my ($line, $lineno) = (shift, shift);
 684     return (($lineno == 1 && $line =~ /^!!SEQUENCE_LIST/) ||
 685             ($lineno == 2 &&
 686              $line =~ /^[[:upper:]]*BLAST[[:upper:]]*.*\[.*\]$/));
 687 }
 688
 689 =head2 _possibly_gcgfasta
 690
 691 From bioperl testdata.
 692
 693 =cut
 694
 695 sub _possibly_gcgfasta
 696 {
 697     my ($line, $lineno) = (shift, shift);
 698     return (($lineno == 1 && $line =~ /^!!SEQUENCE_LIST/) ||
 699             ($lineno == 2 && $line =~ /FASTA/));
 700 }
 701
 702 =head2 _possibly_gde
 703
 704 From "http://www.ebi.ac.uk/help/formats.html".
 705
 706 =cut
 707
 708 sub _possibly_gde
 709 {
 710     my ($line, $lineno) = (shift, shift);
 711     return ($line =~ /^[{}]$/ ||
 712             $line =~ /^(?:name|longname|sequence-ID|
 713                           creation-date|direction|strandedness|
 714                           type|offset|group-ID|creator|descrip|
 715                           comment|sequence)/x);
 716 }
 717
 718 =head2 _possibly_genbank
 719
 720 From "http://www.ebi.ac.uk/help/formats.html".
 721 Format of [apparantly optional] file header from
 722 "http://www.umdnj.edu/rcompweb/PA/Notes/GenbankFF.htm". (TODO: dead link)
 723
 724 =cut
 725
 726 sub _possibly_genbank
 727 {
 728     my ($line, $lineno) = (shift, shift);
 729     return (($lineno == 1 && $line =~ /GENETIC SEQUENCE DATA BANK/) ||
 730             ($lineno == 1 && $line =~ /^LOCUS /) ||
 731             ($lineno == 2 && $line =~ /^DEFINITION /) ||
 732             ($lineno == 3 && $line =~ /^ACCESSION /));
 733 }
 734
 735 =head2 _possibly_genscan
 736
 737 From bioperl test data.
 738
 739 =cut
 740
 741 sub _possibly_genscan
 742 {
 743     my ($line, $lineno) = (shift, shift);
 744     return (($lineno == 1 && $line =~ /^GENSCAN.*Date.*Time/) ||
 745             ($line =~ /^(?:Sequence\s+\w+|Parameter matrix|Predicted genes)/));
 746 }
 747
 748 =head2 _possibly_gff
 749
 750 From bioperl test data.
 751
 752 =cut
 753
 754 sub _possibly_gff
 755 {
 756     my ($line, $lineno) = (shift, shift);
 757     return (($lineno == 1 && $line =~ /^##gff-version/) ||
 758             ($lineno == 2 && $line =~ /^##date/));
 759 }
 760
 761 =head2 _possibly_hmmer
 762
 763 From bioperl test data.
 764
 765 =cut
 766
 767 sub _possibly_hmmer
 768 {
 769     my ($line, $lineno) = (shift, shift);
 770     return (($lineno == 2 && $line =~ /^HMMER/) ||
 771             ($lineno == 3 &&
 772              $line =~ /Washington University School of Medicine/));
 773 }
 774
 775 =head2 _possibly_nexus
 776
 777 From "http://paup.csit.fsu.edu/nfiles.html".
 778
 779 =cut
 780
 781 sub _possibly_nexus
 782 {
 783     my ($line, $lineno) = (shift, shift);
 784     return ($lineno == 1 && $line =~ /^#NEXUS/);
 785 }
 786
 787 =head2 _possibly_mase
 788
 789 From bioperl test data.
 790 More detail from "http://www.umdnj.edu/rcompweb/PA/Notes/GenbankFF.htm" (TODO: dead link)
 791
 792 =cut
 793
 794 sub _possibly_mase
 795 {
 796     my ($line, $lineno) = (shift, shift);
 797     return (($lineno == 1 && $line =~ /^;;/) ||
 798             ($lineno > 1 && $line =~ /^;[^;]?/));
 799 }
 800
 801 =head2 _possibly_mega
 802
 803 From the ensembl broswer (AlignView data export).
 804
 805 =cut
 806
 807 sub _possibly_mega
 808 {
 809     my ($line, $lineno) = (shift, shift);
 810     return ($lineno == 1 && $line =~ /^#mega$/);
 811 }
 812
 813
 814 =head2 _possibly_msf
 815
 816 From "http://www.ebi.ac.uk/help/formats.html".
 817
 818 =cut
 819
 820 sub _possibly_msf
 821 {
 822     my ($line, $lineno) = (shift, shift);
 823     return ($line =~ m{^//} ||
 824             $line =~ /MSF:.*Type:.*Check:|Name:.*Len:/);
 825 }
 826
 827 =head2 _possibly_phrap
 828
 829 From "http://biodata.ccgb.umn.edu/docs/contigimage.html". (TODO: dead link)
 830 From "http://genetics.gene.cwru.edu/gene508/Lec6.htm".    (TODO: dead link)
 831 From bioperl test data ("*.ace.1" files).
 832
 833 =cut
 834
 835 sub _possibly_phrap
 836 {
 837     my ($line, $lineno) = (shift, shift);
 838     return ($line =~ /^(?:AS\ |CO\ Contig|BQ|AF\ |BS\ |RD\ |
 839                           QA\ |DS\ |RT\{)/x);
 840 }
 841
 842 =head2 _possibly_pir
 843
 844 From "http://www.ebi.ac.uk/help/formats.html".
 845 The ".,()" spotted in bioperl test data.
 846
 847 =cut
 848
 849 sub _possibly_pir # "NBRF/PIR" (?)
 850 {
 851     my ($line, $lineno) = (shift, shift);
 852     return (($lineno != 1 && $line =~ /^[\sA-IK-NP-Z.,()]+\*?$/i) ||
 853             $line =~ /^>(?:P1|F1|DL|DC|RL|RC|N3|N1);/);
 854 }
 855
 856 =head2 _possibly_pfam
 857
 858 From bioperl test data.
 859
 860 =cut
 861
 862 sub _possibly_pfam
 863 {
 864     my ($line, $lineno) = (shift, shift);
 865     return ($line =~ m{^\w+/\d+-\d+\s+[A-IK-NP-Z.]+}i);
 866 }
 867
 868 =head2 _possibly_phylip
 869
 870 From "http://www.ebi.ac.uk/help/formats.html".  Initial space
 871 allowed on first line (spotted in ensembl AlignView exported
 872 data).
 873
 874 =cut
 875
 876 sub _possibly_phylip
 877 {
 878     my ($line, $lineno) = (shift, shift);
 879     return (($lineno == 1 && $line =~ /^\s*\d+\s\d+/) ||
 880             ($lineno == 2 && $line =~ /^\w\s+[A-IK-NP-Z\s]+/) ||
 881             ($lineno == 3 && $line =~ /(?:^\w\s+[A-IK-NP-Z\s]+|\s+[A-IK-NP-Z\s]+)/)
 882            );
 883 }
 884
 885 =head2 _possibly_prodom
 886
 887 From "http://prodom.prabi.fr/prodom/current/documentation/data.php".
 888
 889 =cut
 890
 891 sub _possibly_prodom
 892 {
 893     my ($line, $lineno) = (shift, shift);
 894     return ($lineno == 1 && $line =~ /^ID   / && $line =~ /\d+ seq\.$/);
 895 }
 896
 897 =head2 _possibly_raw
 898
 899 From "http://www.ebi.ac.uk/help/formats.html".
 900
 901 =cut
 902
 903 sub _possibly_raw
 904 {
 905     my ($line, $lineno) = (shift, shift);
 906     return ($line =~ /^[A-Za-z\s]+$/);
 907 }
 908
 909 =head2 _possibly_rsf
 910
 911 From "http://www.ebi.ac.uk/help/formats.html".
 912
 913 =cut
 914
 915 sub _possibly_rsf
 916 {
 917     my ($line, $lineno) = (shift, shift);
 918     return (($lineno == 1 && $line =~ /^!!RICH_SEQUENCE/) ||
 919             $line =~ /^[{}]$/ ||
 920             $line =~ /^(?:name|type|longname|
 921                           checksum|creation-date|strand|sequence)/x);
 922 }
 923
 924 =head2 _possibly_selex
 925
 926 From "http://www.ebc.ee/WWW/hmmer2-html/node27.html".
 927
 928 Assuming presence of Selex file header.  Data exported by
 929 Bioperl on Pfam and Selex formats are identical, but Pfam file
 930 only holds one alignment.
 931
 932 =cut
 933
 934 sub _possibly_selex
 935 {
 936     my ($line, $lineno) = (shift, shift);
 937     return (($lineno == 1 && $line =~ /^#=ID /) ||
 938             ($lineno == 2 && $line =~ /^#=AC /) ||
 939             ($line =~ /^#=SQ /));
 940 }
 941
 942 =head2 _possibly_stockholm
 943
 944 From bioperl test data.
 945
 946 =cut
 947
 948 sub _possibly_stockholm
 949 {
 950     my ($line, $lineno) = (shift, shift);
 951     return (($lineno == 1 && $line =~ /^# STOCKHOLM/) ||
 952             $line =~ /^#=(?:GF|GS) /);
 953 }
 954
 955
 956
 957 =head2 _possibly_swiss
 958
 959 From "http://ca.expasy.org/sprot/userman.html#entrystruc".
 960
 961 =cut
 962
 963 sub _possibly_swiss
 964 {
 965     my ($line, $lineno) = (shift, shift);
 966     return ($lineno == 1 && $line =~ /^ID   / && $line =~ /AA\.$/);
 967 }
 968
 969 =head2 _possibly_tab
 970
 971 Contributed by Heikki.
 972
 973 =cut
 974
 975 sub _possibly_tab
 976 {
 977     my ($line, $lineno) = (shift, shift);
 978     return ($lineno == 1 && $line =~ /^[^\t]+\t[^\t]+/) ;
 979 }
 980
 981 =head2 _possibly_vcf
 982
 983 From "http://www.1000genomes.org/wiki/analysis/vcf4.0".
 984
 985 Assumptions made about sanity - format and date lines are line 1 and 2
 986 respectively. This is not specified in the format document.
 987
 988 =cut
 989
 990 sub _possibly_vcf
 991 {
 992     my ($line, $lineno) = (shift, shift);
 993     return (($lineno == 1 && $line =~ /##fileformat=VCFv/) ||
 994             ($lineno == 2 && $line =~ /##fileDate=/));
 995 }
 996
 997
 998
 999 1;