bash/step6_file.sh

   1 #!/bin/bash
   2
   3 INTERACTIVE=${INTERACTIVE-yes}
   4
   5 source $(dirname $0)/reader.sh
   6 source $(dirname $0)/printer.sh
   7 source $(dirname $0)/env.sh
   8 source $(dirname $0)/core.sh
   9
  10 # READ: read and parse input
  11 READ () {
  12     [ "${1}" ] && r="${1}" || READLINE
  13     READ_STR "${r}"
  14 }
  15
  16 EVAL_AST () {
  17     local ast="${1}" env="${2}"
  18     #_pr_str "${ast}"; echo "EVAL_AST '${ast}:${r} / ${env}'"
  19     _obj_type "${ast}"; local ot="${r}"
  20     case "${ot}" in
  21     symbol)
  22         local val="${ANON["${ast}"]}"
  23         ENV_GET "${env}" "${val}"
  24         return ;;
  25     list)
  26         _map_with_type _list EVAL "${ast}" "${env}" ;;
  27     vector)
  28         _map_with_type _vector EVAL "${ast}" "${env}" ;;
  29     hash_map)
  30         local res="" val="" hm="${ANON["${ast}"]}"
  31         _hash_map; local new_hm="${r}"
  32         eval local keys="\${!${hm}[@]}"
  33         for key in ${keys}; do
  34             eval val="\${${hm}[\"${key}\"]}"
  35             EVAL "${val}" "${env}"
  36             _assoc! "${new_hm}" "${key}" "${r}"
  37         done
  38         r="${new_hm}" ;;
  39     *)
  40         r="${ast}" ;;
  41     esac
  42 }
  43
  44 # EVAL: evaluate the parameter
  45 EVAL () {
  46     local ast="${1}" env="${2}"
  47     while true; do
  48     r=
  49     [[ "${__ERROR}" ]] && return 1
  50     #_pr_str "${ast}"; echo "EVAL '${r} / ${env}'"
  51     _obj_type "${ast}"; local ot="${r}"
  52     if [[ "${ot}" != "list" ]]; then
  53         EVAL_AST "${ast}" "${env}"
  54         return
  55     fi
  56
  57     # apply list
  58     _nth "${ast}" 0; local a0="${r}"
  59     _nth "${ast}" 1; local a1="${r}"
  60     _nth "${ast}" 2; local a2="${r}"
  61     case "${ANON["${a0}"]}" in
  62         def!) local k="${ANON["${a1}"]}"
  63               #echo "def! ${k} to ${a2} in ${env}"
  64               EVAL "${a2}" "${env}"
  65               ENV_SET "${env}" "${k}" "${r}"
  66               return ;;
  67         let*) ENV "${env}"; local let_env="${r}"
  68               local let_pairs=(${ANON["${a1}"]})
  69               local idx=0
  70               #echo "let: [${let_pairs[*]}] for ${a2}"
  71               while [[ "${let_pairs["${idx}"]}" ]]; do
  72                   EVAL "${let_pairs[$(( idx + 1))]}" "${let_env}"
  73                   ENV_SET "${let_env}" "${ANON["${let_pairs[${idx}]}"]}" "${r}"
  74                   idx=$(( idx + 2))
  75               done
  76               EVAL "${a2}" "${let_env}"
  77               return ;;
  78         do)   _count "${ast}"
  79               _slice "${ast}" 1 $(( ${r} - 2 ))
  80               EVAL_AST "${r}" "${env}"
  81               [[ "${__ERROR}" ]] && r= && return 1
  82               _last "${ast}"
  83               ast="${r}"
  84               # Continue loop
  85               ;;
  86         if)   EVAL "${a1}" "${env}"
  87               if [[ "${r}" == "${__false}" || "${r}" == "${__nil}" ]]; then
  88                   # eval false form
  89                   _nth "${ast}" 3; local a3="${r}"
  90                   if [[ "${a3}" ]]; then
  91                       ast="${a3}"
  92                   else
  93                       r="${__nil}"
  94                       return
  95                   fi
  96               else
  97                   # eval true condition
  98                   ast="${a2}"
  99               fi
 100               # Continue loop
 101               ;;
 102         fn*)  _function "ENV \"${env}\" \"${a1}\" \"\${@}\"; \
 103                          EVAL \"${a2}\" \"\${r}\"" \
 104                         "${a2}" "${env}" "${a1}"
 105               return ;;
 106         *)    EVAL_AST "${ast}" "${env}"
 107               [[ "${__ERROR}" ]] && r= && return 1
 108               local el="${r}"
 109               _first "${el}"; local f="${ANON["${r}"]}"
 110               _rest "${el}"; local args="${ANON["${r}"]}"
 111               #echo "invoke: [${f}] ${args}"
 112               if [[ "${f//@/ }" != "${f}" ]]; then
 113                   set -- ${f//@/ }
 114                   ast="${2}"
 115                   ENV "${3}" "${4}" ${args}
 116                   env="${r}"
 117               else
 118                   eval ${f%%@*} ${args}
 119                   return
 120               fi
 121               # Continue loop
 122               ;;
 123     esac
 124     done
 125 }
 126
 127 # PRINT:
 128 PRINT () {
 129     if [[ "${__ERROR}" ]]; then
 130         _pr_str "${__ERROR}" yes
 131         r="Error: ${r}"
 132         __ERROR=
 133     else
 134         _pr_str "${1}" yes
 135     fi
 136 }
 137
 138 # REPL: read, eval, print, loop
 139 ENV; REPL_ENV="${r}"
 140 REP () {
 141     r=
 142     READ "${1}" || return 1
 143     EVAL "${r}" "${REPL_ENV}"
 144     PRINT "${r}"
 145 }
 146
 147 # core.sh: defined using bash
 148 _fref () { _function "${2} \"\${@}\""; ENV_SET "${REPL_ENV}" "${1}" "${r}"; }
 149 for n in "${!core_ns[@]}"; do _fref "${n}" "${core_ns["${n}"]}"; done
 150 _eval () { EVAL "${1}" "${REPL_ENV}"; }
 151 _fref "eval" _eval
 152
 153 # core.mal: defined using the language itself
 154 REP "(def! not (fn* (a) (if a false true)))"
 155 REP "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
 156
 157 if [[ "${1}" ]]; then
 158     echo "${@}"
 159     REP "(load-file \"${1}\")" && echo "${r}"
 160 elif [[ -n "${INTERACTIVE}" ]]; then
 161     while true; do
 162         READLINE "user> " || exit "$?"
 163         [[ "${r}" ]] && REP "${r}" && echo "${r}"
 164     done
 165 fi