bash/step1_read_print.sh

   1 #!/usr/bin/env bash
   2
   3 source $(dirname $0)/reader.sh
   4 source $(dirname $0)/printer.sh
   5
   6 # read
   7 READ () {
   8     [ "${1}" ] && r="${1}" || READLINE
   9     READ_STR "${r}"
  10 }
  11
  12 # eval
  13 EVAL () {
  14     local ast="${1}"
  15     local env="${2}"
  16     r=
  17     [[ "${__ERROR}" ]] && return 1
  18     r="${ast}"
  19 }
  20
  21 # print
  22 PRINT () {
  23     if [[ "${__ERROR}" ]]; then
  24         _pr_str "${__ERROR}" yes
  25         r="Error: ${r}"
  26         __ERROR=
  27     else
  28         _pr_str "${1}" yes
  29     fi
  30 }
  31
  32 # repl
  33 REP () {
  34     READ "${1}"
  35     EVAL "${r}"
  36     PRINT "${r}"
  37 }
  38
  39 # repl loop
  40 while true; do
  41     READLINE "user> " || exit "$?"
  42     [[ "${r}" ]] && REP "${r}" && echo "${r}"
  43 done