proto-action.raku

#!/usr/bin/env raku
grammar Calculator {
    token TOP { <calc-op> }

    proto rule calc-op          {*}
          rule calc-op:sym<add> { <num> '+' <num> }
          rule calc-op:sym<sub> { <num> '-' <num> }

    token num { \d+ }
}

class Calculations {
    method TOP              ($/) { make $<calc-op>.made; }
    proto method calc-op($/) { say 'ASD'; {*} }
    method calc-op:sym<add> ($/) { make [+] $<num>; }
    method calc-op:sym<sub> ($/) { make [-] $<num>; }
}

say Calculator.parse('2 + 3', actions => Calculations).made;

# OUTPUT: «5␤»