more openresty ...

[mnegovanovic]

Hi,

in Lua we usually have this kind of pattern:

      local res = db:query(sql)
      for i, ad in ipairs(res) do
        ads[i] = {}
        ads[i]["title"] = ad["title"]
        ads[i]["seo_title"] = ad["seo_title"]
        ads[i]["content"] = string.sub(ad["content"], 1, 150)
        ads[i]["location"] = ad["location"]
        ads[i]["parttime"] = tonumber(ad["parttime"])
        ads[i]["expires"] = ad["expires"]
        ads[i]["salary"] = s.getSalaryCode(ad["salary"])
      end

How do i emulate this (how to use ipairs from SML) pattern. So far ive got this:

      fun myQuery (db: Lua.value) (sql: string) =
          let
              val res = Lua.method1 (db, "query") #[Lua.fromString sql]                     
              val length = Lua.length res                                                   
          in                                                                                
              res
          end                                                                                     
      val res = myQuery db "select * from ads;"

To summarise ... i can obtain Lua.value res which represents the result of the SQL database operation. I need to iterate through it in SML ... are there any convenience methods?

Regards

[mnegovanovic]

Ive played around with Lua.Lib.next:

  fun rsToPairs (t: Lua.value): (int * (string * string) list) list =
      let
          fun extractRow_ NONE _ acc = acc
              | extractRow_ (SOME row) i acc =
                  let
                      val (next_i, next_v) = Lua.call2 Lua.Lib.next #[row, i]
                  in
                      if Lua.isNil next_v then
                          extractRow_ NONE next_i acc
                      else
                          let
                              val next_i_str = Lua.unsafeFromValue next_i : string
                              val next_v_str = Lua.unsafeFromValue next_v : string
                          in
                              extractRow_ (SOME row) next_i ((next_i_str, next_v_str)::acc)
                          end
                  end

          fun extractTable_ NONE _ acc = acc
              | extractTable_ (SOME t) i acc =
                  let
                      val (next_i, next_v) = Lua.call2 Lua.Lib.next #[t, i]
                  in
                      if Lua.isNil next_v then
                          extractTable_ NONE next_i acc
                      else
                          let
                              val next_i_int = Lua.unsafeFromValue next_i : int
                              val next_v_extracted = extractRow_ (SOME next_v) Lua.NIL []
                          in
                              extractTable_ (SOME t) next_i ((next_i_int, next_v_extracted)::acc)
                          end
                  end
      in
          extractTable_ (SOME t) Lua.NIL []
      end

... so ive got something going. If you know of a better way please do tell.

Regards