Class: LookupChain

Inherits:
Object
  • Object
show all
Defined in:
lib/lookup_chain.rb

Overview

Manages a list of lookup objects, prioritizing the matches from the later objects over matches from previous objects in cases of exact collisions or cases where two matches have the same length. Otherwise, when there are overlaps, the longest match always wins.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*lookups) ⇒ LookupChain

Returns a new instance of LookupChain.



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# File 'lib/lookup_chain.rb', line 13

def initialize(*lookups)
  @lookups = []
  lookups.flatten!

  lookups.each do |lookup|
    check_lookup(lookup)
    @lookups << lookup
  end
end

Instance Attribute Details

#lookups ⇒ Object (readonly)

Returns the value of attribute lookups.



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# File 'lib/lookup_chain.rb', line 11

def lookups
  @lookups
end

Instance Method Details

#<<(lookup) ⇒ Object 



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# File 'lib/lookup_chain.rb', line 23

def <<(lookup)
  check_lookup(lookup)

  self.lookups << lookup
end

#process(text) ⇒ Object 



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# File 'lib/lookup_chain.rb', line 29

def process(text)
  matches = []

  @lookups.each do |lookup|
    new_matches = lookup.process(text)
    matches += new_matches
    matches.sort!
    i = 0
    while(i+1 < matches.size)
      (match1, match2) = matches[i,2]

      if(match1.overlap?(match2))
        if (match1.length > match2.length)
          matches.delete_at(i+1)
        elsif (match1.length < match2.length)
          matches.delete_at(i)
        else
          if (new_matches.include?(match1))
            matches.delete_at(i)
          else
            matches.delete_at(i+1)
          end
        end
      else
        i += 1
      end
    end
  end

  return matches
end