# Selima Website Content Management System
# Query.pm: The search string parser.

#  Copyright (c) 2004-2018 imacat.
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

# Author: imacat <imacat@mail.imacat.idv.tw>
# First written: 2004-09-12

package Selima::Query;
use 5.008;
use strict;
use warnings;
use base qw(Exporter);
use vars qw(@EXPORT @EXPORT_OK);
BEGIN {
@EXPORT = qw(parse_query);
@EXPORT_OK = @EXPORT;
# Prototype declaration
sub parse_query($);
}

# parse_query: Parse the query string into multiple search phrases
sub parse_query($) {
    local ($_, %_);
    $_ = $_[0];
    
    s/^\s*(.*?)\s*$/$1/;
    @_ = qw();
    while ($_ ne "") {
        # Non-quoted word
        if (s/^([^\s"']+)\s*//) {                   # " gettext
            push @_, $1;
        # Double-quoted string
        } elsif (s/^"((?:[^\\"]|\\.)+)"?\s*//) {    # " gettext
            eval "push \@_, \"$1\";\n";
        # Single-quoted string
        } elsif (s/^'((?:[^\\']|\\.)+)'?\s*//) {    # ' gettext
            eval "push \@_, '$1';\n";
        # Discard empty quoted strings
        } elsif (s/^(?:""?|''?)\s*//) {
        }
    }
    return @_;
}

return 1;