awk/step0_repl.awk

   1 function READ(str)
   2 {
   3         return str
   4 }
   5
   6 function EVAL(ast)
   7 {
   8         return ast
   9 }
  10
  11 function PRINT(expr)
  12 {
  13         return expr
  14 }
  15
  16 function rep(str)
  17 {
  18         return PRINT(EVAL(READ(str)))
  19 }
  20
  21 function main(str)
  22 {
  23         while (1) {
  24                 printf("user> ")
  25                 if (getline str <= 0) {
  26                         break
  27                 }
  28                 print rep(str)
  29         }
  30 }
  31
  32 BEGIN {
  33         main()
  34         exit(0)
  35 }