     nm: (raw, type, terminal)->
         terminal ?= null
         value = if terminal then terminal.value else null
-        $ =
+        $$ =
             node: 'nm'
             raw: raw
             type: type

    ecmd: (explain, cmd)->
        explain ?= null
        cmd ?= null
        $ =
            node: 'ecmd'
            explain: explain
            cmd: cmd
    explain: (explain, queryPlan)->
        $ =
            node: 'explain'
            explain: explain
            queryPlan: queryPlan

            terminal: terminal

    dbnm: (nm)->
        $$ =
            node: 'dbnm'
            nm: nm

    trans_opt: (nm)->
        nm ?= null
        $$ =
            node: 'trans_opt'
            value: nm

    transtype: (type)->
        type ?= null
        $$ =
            node: 'transtype'
            type: type

