use strict;
use warnings;
use HOP::Lexer 'string_lexer';
use Data::Dumper;
my $document = join '', <DATA>;

my @keywords = (
    'PRODUCT:',
    'SUBJECT:',
    'SUBMITTED BY:',
    'SUBMITTED DATE:',
    'IR #:',
    'DOCUMENT ID:',
    'PLATFORM:',
    'OPERATING SYSTEM:',
    'OS VERSION:',
    'PRODUCT VERSION:'
);

my @input_tokens = (
    [ 'KEYWORD', qr/(?i:@{[join '|', map {$_} @keywords]})/ ],
    [ 'TEXT', qr/(.*)/, \&text ],
);

my $lexer = string_lexer( $document, @input_tokens );

while ( defined( my $token = $lexer->() ) ) {
    my ( $label, $value ) = @$token;
    print $label, "  =>  ", $value, "\n";

    #print Dumper($token);

}

sub text {
    my ( $label, $value ) = @_;
    for ($value) {
        s/^\s+//;
        s/\s+$//;
    }

    return [ $label, $value ];
}

__DATA__
PRODUCT:      NX_Nastran
SUBJECT: How can I multiply the displacement vector by a matrix?

SUBMITTED BY: TOM ZHANG                 SUBMITTED DATE:   02/07/2006
IR #:         5395926                   DOCUMENT ID:      001-5395926
PLATFORM:     INTEL                     OPERATING SYSTEM: WINDOW
OS VERSION:   XP32_SP2                  PRODUCT VERSION:  V4.0

======================================================================
+=========

HARDWARE
--------
Family        : NX_NASTRAN
Application : NASTRAN
Function    : DMAP
Subfunction : ALL
Release     : V4.0

Platform    : INTEL
OS        : WINDOW
OS Version  : XP32_SP2

SYMPTOM
-------
This article discusses writing a DMAP that performs multiplication of 
+the 
displacement vector by a matrix. SOL 101 is used. The article discusse
+s 
these concerns:

1. what data block is the displacement vector?
2. how to handle multiple subcases?
3. which print module to use

SOLUTION
--------
Answer:
1. The displacement vector is UG. It is generated in subDMAP SEDISP (y
+ou can 
use DIAG 14 to print the whole thing in the f06 file and search for SE
+DISP).
You can put your alter in any place in SEDISP after it is created. A s
+uggested 
entry point is after line 587. You can use something like ALTER 'CALL 
+SESUM' 
this is better than "ALTER 587' because the latter would break if the 
+subDMAP 
SEDISP changed.

REFERENCES
----------------

======================================================================
+=========

-- End of document --
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