Data commit

Task/Soundex/Lua/soundex.lua

@@ -0,0 +1,42 @@
+local d, digits, alpha = '01230120022455012623010202', {}, ('A'):byte()
+d:gsub(".",function(c)
+  digits[string.char(alpha)] = c
+  alpha = alpha + 1
+end)
+
+function soundex(w)
+  local res = {}
+  for c in w:upper():gmatch'.'do
+    local d = digits[c]
+    if d then
+      if #res==0 then
+        res[1] =  c
+      elseif #res==1 or d~= res[#res] then
+        res[1+#res] = d
+      end
+    end
+  end
+  if #res == 0 then
+    return '0000'
+  else
+    res = table.concat(res):gsub("0",'')
+    return (res .. '0000'):sub(1,4)
+  end
+end
+
+-- tests
+local tests = {
+  {"",         "0000"}, {"12346",     "0000"},
+  {"he",       "H000"}, {"soundex",   "S532"},
+  {"example",  "E251"}, {"ciondecks", "C532"},
+  {"ekzampul", "E251"}, {"résumé",  "R250"},
+  {"Robert",   "R163"}, {"Rupert",    "R163"},
+  {"Rubin",    "R150"}, {"Ashcraft",  "A226"},
+  {"Ashcroft", "A226"}
+}
+
+for i=1,#tests do
+  local itm = tests[i]
+  assert( soundex(itm[1])==itm[2] )
+end
+print"all tests ok"