2019/day1.m4

   1 divert(-1)dnl -*- m4 -*-
   2 # Usage: m4 [-Dfile=day1.input] day1.m4
   3
   4 include(`common.m4')ifelse(common(1), `ok', `',
   5 `errprint(`Missing common initialization
   6 ')m4exit(1)')
   7
   8 define(`part1', 0)
   9 define(`part2', 0)
  10 define(`compute', `_$0($1)ifelse($2, `', `', `$0(shift($@))')')
  11 define(`_compute',
  12   `define(`part1', eval(part1 + $1 / 3 - 2))do(eval($1 / 3 - 2))')
  13 define(`do', `ifelse(eval($1 > 8), 1, `do(eval($1 / 3 - 2))')define(`part2',
  14   eval(part2 + $1))')
  15 compute(translit(include(defn(`file')), `
  16 ', `,'))
  17
  18 divert`'part1
  19 part2