DSL EXPRESSION:
  if (NR==1) {
    $x = 2;
    $y = 3
  }


AST:
* statement block
    * if-chain
        * if-item "if"
            * operator "=="
                * context variable "NR"
                * int literal "1"
            * statement block
                * assignment "="
                    * direct field value "x"
                    * int literal "2"
                * assignment "="
                    * direct field value "y"
                    * int literal "3"

i=1,x=2,y=3
i=2,x=102,y=202
i=3,x=103,y=203
i=4,x=104,y=204
i=5,x=105,y=205
i=6,x=106,y=206
i=7,x=107,y=207
i=8,x=108,y=208
i=9,x=109,y=209
i=10,x=110,y=210
i=11,x=111,y=211
i=12,x=112,y=212
i=13,x=113,y=213
i=14,x=114,y=214
i=15,x=115,y=215
i=16,x=116,y=216
i=17,x=117,y=217
i=18,x=118,y=218
i=19,x=119,y=219
i=20,x=120,y=220
i=21,x=121,y=221
i=22,x=122,y=222
i=23,x=123,y=223
i=24,x=124,y=224
i=25,x=125,y=225
i=26,x=126,y=226
i=27,x=127,y=227
i=28,x=128,y=228
i=29,x=129,y=229
i=30,x=130,y=230
i=31,x=131,y=231
i=32,x=132,y=232
i=33,x=133,y=233
i=34,x=134,y=234
i=35,x=135,y=235
i=36,x=136,y=236
i=37,x=137,y=237
i=38,x=138,y=238
i=39,x=139,y=239
i=40,x=140,y=240
