DSL EXPRESSION:
for(k,v in $*) {$[k."_orig"]=v; $[k] = "other"}


AST:
* statement block
    * double-variable for-loop "for"
        * local variable "k"
        * local variable "v"
        * full record "$*"
        * statement block
            * assignment "="
                * indirect field value "$[]"
                    * dot operator "."
                        * local variable "k"
                        * string literal "_orig"
                * local variable "v"
            * assignment "="
                * indirect field value "$[]"
                    * local variable "k"
                * string literal "other"

a     b     i     x     y     a_orig b_orig i_orig x_orig     y_orig
other other other other other pan    pan    1      0.34679014 0.72680286
other other other other other eks    pan    2      0.75867996 0.52215111
other other other other other wye    wye    3      0.20460331 0.33831853
other other other other other eks    wye    4      0.38139939 0.13418874
other other other other other wye    pan    5      0.57328892 0.86362447
other other other other other zee    pan    6      0.52712616 0.49322129
other other other other other eks    zee    7      0.61178406 0.18788492
other other other other other zee    wye    8      0.59855401 0.97618139
other other other other other hat    wye    9      0.03144188 0.74955076
other other other other other pan    wye    10     0.50262601 0.95261836
