require File.dirname(FILE) << ’/keyword_search/definition.rb‘
module KeywordSearch
class ParseError < ::SyntaxError; end
class << self
%%{
machine parser;
action start {
tokstart = p;
}
action key {
key = data[tokstart...p-1]
results[key] ||= []
}
action default {
key = nil
}
action value {
value = data[tokstart..p-1]
value = value[1..-2] if ["'", '"'].include?(value[0,1])
(results[key || :default] ||= []) << value
}
action quote { quotes += 1 }
action unquote { quotes -= 1 }
bareword = [^ '":] [^ ":]*; # allow apostrophes
dquoted = '"' @ quote any* :>> '"' @ unquote;
squoted = '\'' @ quote any* :>> '\'' @ unquote;
value = ( dquoted | squoted | bareword );
pair = (bareword > start ':') % key value > start % value ;
definition = ( pair | value > start > default % value) ' ';
main := definition** 0
@!{ raise ParseError, "At offset #{p}, near: '#{data[p,10]}'" };
}%%
def search(input_string, definition=nil, &block)
definition ||= Definition.new(&block)
results = parse(input_string)
results.each do |key, terms|
definition.handle(key, terms)
end
results
end
#######
private
#######
def parse(input) #:nodoc:
data = input + ' '
%% write data;
p = 0
pe = data.length
key = nil
tokstart = nil
results = {}
quotes = 0
%% write init;
%% write exec;
%% write eof;
unless quotes.zero?
raise ParseError, "Unclosed quotes"
end
results
end
end
end