Question

I need to search for a partial match in an inverted index, following code works for exact matches but not for partial. Reworked this from the example at http://rosettacode.org/wiki/Inverted_Index (which no longer works in Ruby1.9.3)

How to do that the most efficient way please ?
Please no advise about using Lucene, Sphinx etc unless you know a lightweight, simple and pure Ruby solution, want to do it myself.

@data = {"contents"=>["1.txt", "2.txt"], "of"=>["1.txt", "2.txt"], "file"=>["1.txt", "2.txt"], "one"=>["1.txt"], "two"=>["2.txt"]}

def search words
  result = []
  words.each do |word|
    result << @data[word] if @data[word] #should do a partial match
  end
  result
end

p search ['of'] #=> [["1.txt", "2.txt"]]
p search ['one'] #=> [["1.txt"]]
p search ['on']  #=> []                    <<should become [["1.txt"]]

Answer 1

Define search as follows:

def search words
  words.map do |word|
    matches = @data.keys.select {|key| key.include?(word)}
    matches.map {|match| @data[match] }
  end      
end

p search ['of'] #=> [[["1.txt", "2.txt"]]]
p search ['one'] #=> [[["1.txt"]]]
p search ['on']  #=> [[["1.txt", "2.txt"], ["1.txt"]]] - note that "contents" contains "on"