
mlr -n put -v for (k             in @*) {}
DSL EXPRESSION:
for (k             in @*) {}

AST:
* statement block
    * single-variable for-loop "for"
        * local variable "k"
        * full oosvar "@*"
        * statement block


mlr -n put -v for (k, v          in @*) {}
DSL EXPRESSION:
for (k, v          in @*) {}

AST:
* statement block
    * double-variable for-loop "for"
        * local variable "k"
        * local variable "v"
        * full oosvar "@*"
        * statement block


mlr -n put -v for ((k1,k2),    v in @*) {}
DSL EXPRESSION:
for ((k1,k2),    v in @*) {}

AST:
* statement block
    * multi-variable for-loop "for"
        * parameter list
            * local variable "k1"
            * local variable "k2"
        * local variable "v"
        * full oosvar "@*"
        * statement block


mlr -n put -v for ((k1,k2,k3), v in @*) {}
DSL EXPRESSION:
for ((k1,k2,k3), v in @*) {}

AST:
* statement block
    * multi-variable for-loop "for"
        * parameter list
            * local variable "k1"
            * local variable "k2"
            * local variable "k3"
        * local variable "v"
        * full oosvar "@*"
        * statement block


