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
|
#! /usr/local/bin/perl -sw
use vars qw($animal);
use Parse::RecDescent;
$RD_AUTOACTION = q{ $last = $item[1] };
$grammar = q {
sequence: <rulevar: local $last>
sequence: base <matchrule: after_$last >(3..)
{ [ $item[1], @{$item[2]} ] }
| base sequence
{ $item[2] }
base: /[ACGT]/
after_A: /[C]/
after_C: /[AG]/
after_G: /[CT]/
after_T: /[G]/
};
$parser = new Parse::RecDescent( $grammar ) or
die "bad grammar; bailing";
local $/;
use AutoDump;
show $parser->sequence(<DATA>);
__DATA__
AAACTTTAAAACGTGCGCACGTGTAAAAAA
|
