jq/step1_read_print.jq

   1 include "reader";
   2 include "printer";
   3 include "utils";
   4
   5 def read_line:
   6     . as $in
   7     | label $top
   8     | _readline;
   9
  10 def READ:
  11     read_str | read_form | .value;
  12
  13 def EVAL:
  14     .;
  15
  16 def PRINT:
  17     pr_str;
  18
  19 def rep:
  20     READ | EVAL |
  21         if . != null then
  22             PRINT
  23         else
  24             null
  25         end;
  26
  27 def repl_:
  28     ("user> " | _print) |
  29     (read_line | rep);
  30
  31 def repl:
  32     {continue: true} | while(
  33         .continue;
  34         try {value: repl_, continue: true}
  35         catch
  36             if is_jqmal_error then
  37                 {value: "Error: \(.)", continue: true}
  38             else
  39                 {value: ., continue: false}
  40             end) | if .value then .value|_display else empty end;
  41
  42 repl