Elasticsearch query parser experiments

elasticsearch_query_parser.rb

module Elastomer
  module Query
    class ElasticsearchQueryParser < LuceneQueryParser

      rule(:unbounded_range) { gte | lte | gt | lt }
      #TODO range groups e.g. age:(>=10 AND < 20) age:(+>=10 +<20)

      #TODO eliminate duplication
      rule(:field) { word.as(:field) >> str(':') >> (((group | regexp | inclusive_range.as(:inclusive_range) | exclusive_range.as(:exclusive_range)) >> boost.maybe) | ((phrase | term) >> (distance | boost).maybe)) }
    end
  end
end

lucene_query_parser.rb

module Elastomer
  module Query
    class LuceneQueryParser < Parslet::Parser
      rule(:space) { match('\s').repeat(1) }
      rule(:word) { match('\w').repeat(1) }
      rule(:digit) { match('[0-9]') }
      rule(:integer) { digit.repeat(1) }
      rule(:float) { integer >> str('.') >> integer }
      rule(:reserved) { match('[+\-!(){}[]^"~*?:\\/]') | string('&&') | string('||') }
      rule(:wildcard) { str('*') }

      rule(:operator) { (str('AND') | str('OR')).as(:operator) }

      rule(:distance) { str('~') >> digit.as(:distance) }
      rule(:boost) { str('^') >> (integer | float).as(:boost) }

      #TODO disallow unmatched quotes
      rule(:term) { (match('[^?*]') >> match('[\w?*]').repeat).as(:term) >> (distance | boost).maybe }
      #TODO allow escaped quotes
      rule(:phrase) { str('"') >> match('[^"]').repeat(1).as(:phrase) >> str('"') >> (distance | boost).maybe }
      rule(:group) { str('(') >> space.maybe >> query.as(:group) >> space.maybe >> str(')') >> boost.maybe }

      rule(:gt) { str('>') >> space.maybe >> word.as(:gt) }
      rule(:lt) { str('<') >> space.maybe >> word.as(:lt) }
      rule(:gte) { str('>=') >> space.maybe >> word.as(:gte) }
      rule(:lte) { str('<=') >> space.maybe >> word.as(:lte) }

      rule(:bounded_range) { (word | wildcard).as(:from) >> space >> str('TO') >> space >> (word | wildcard).as(:to) }
      rule(:inclusive_range) { str('[') >> space.maybe >> bounded_range >> space.maybe >> str(']') }
      rule(:exclusive_range) { str('{') >> space.maybe >> bounded_range >> space.maybe >> str('}') }

      #TODO allow escaped /
      rule(:regexp) { str('/') >> match('[^/]').repeat(1).as(:regexp) >> str('/') >> boost.maybe}

      rule(:unary_operator) { str('+').as(:required) | str('-').as(:prohibited) | (str('NOT').as(:prohibited) >> space) }

      rule(:field) { word.as(:field) >> str(':') >> (((group | regexp | inclusive_range.as(:inclusive_range) | exclusive_range.as(:exclusive_range)) >> boost.maybe) | ((phrase | term) >> (distance | boost).maybe)) }

      rule(:clause) { unary_operator.maybe >> (group | field | phrase | regexp | term) }
      rule(:query) { space.maybe >> clause >> (space >> (operator >> space >> clause | clause)).repeat >> space.maybe }
      root :query
    end
  end
end