goog-query.lua

#!/usr/bin/lua
--[[
a parser for google-like search queries
]]--


lex_keywords = {
  -- keywords with quotes
  "([a-zA-Z]+)%s*:%s*[\"\']([^\"\']+)[\"\']",
  -- keywords without quotes
  "([a-zA-Z]+)%s*:%s*([^\"\'%s]+)",
  }

function lex(query)
  terms={}

  -- match keywords
  for i,lx in ipairs(lex_keywords) do
    -- match
    for kw, q in query:gmatch(lx) do
      kw = kw:lower()
      -- add it to our terms
      if terms[kw] == nil then
        terms[kw] = {}
      end
      table.insert(terms[kw], q)
    end

    -- remove matched
    query = query:gsub(lx, "")
  end

  terms.query = {query}

  return terms
end

function dump_terms(t)
  for kw, qs in pairs(t) do
    print(kw)
    for i, q in pairs(qs) do
      print("  <" .. q .. ">")
    end
  end
end


local t = lex("blaaa inTitle : 'zuu u' inurl:dfdfdf inurl:34 das ist")
dump_terms(t)