proc jsiJsonVar {data {opts ""}} {
        set res ""

        set keysType    [_getArgValue "keys" $opts]
        set valuesType  [_getArgValue "values" $opts]

        # by default, keys are strings
        if {[string length $keysType] == 0} {
            set keysType "string"
        }
        # by default, values are raw
        if {[string length $valuesType] == 0} {
            set valuesType "raw"
        }

        if {[lsearch -exact $opts "-string"] >= 0} {
            set res [ecJsEscapeQuoteDollar $data]
        } elseif {[lsearch -exact $opts "-number"] >= 0} {
            set res [ecJsEscapeDollar $data]
        } elseif {[lsearch -exact $opts "-boolean"] >= 0} {
            set res [expr {$data == 1 ? "true" : "false"}]
        } elseif {[lsearch -exact $opts "-array"] >= 0} {
            set res "\\[[join $data ,]\\]"
        } elseif {[lsearch -exact $opts "-object"] >= 0} {
            set obj [list]
            foreach {key value} $data {
                set key     [jsiJsonVar $key -${keysType}]
                set value   [jsiJsonVar $value -${valuesType}]

                lappend obj "${key}:${value}"
            }

            set res "\\{[join $obj ,]\\}"
        } elseif {[lsearch -exact $opts "-raw"] >= 0} {
            set res $data
        } else {
            # default type is -string
            set res [jsiJsonVar $data -string]
        }

        return $res
    }

    proc _getArgValue {name opts} {
        set res ""

        if {[set index [lsearch -glob $opts "--${name}=*"]] >= 0} {
            set res [lindex [split [lindex $opts $index] =] 1]
        }

        return $res
    }