impls/bash/step6_file.sh

   1 #!/usr/bin/env bash
   2
   3 source $(dirname $0)/reader.sh
   4 source $(dirname $0)/printer.sh
   5 source $(dirname $0)/env.sh
   6 source $(dirname $0)/core.sh
   7
   8 # read
   9 READ () {
  10     [ "${1}" ] && r="${1}" || READLINE
  11     READ_STR "${r}"
  12 }
  13
  14 # eval
  15 EVAL_AST () {
  16     local ast="${1}" env="${2}"
  17     #_pr_str "${ast}"; echo "EVAL_AST '${ast}:${r} / ${env}'"
  18     _obj_type "${ast}"; local ot="${r}"
  19     case "${ot}" in
  20     symbol)
  21         ENV_GET "${env}" "${ast}"
  22         return ;;
  23     list)
  24         _map_with_type _list EVAL "${ast}" "${env}" ;;
  25     vector)
  26         _map_with_type _vector EVAL "${ast}" "${env}" ;;
  27     hash_map)
  28         local res="" key= val="" hm="${ANON["${ast}"]}"
  29         _hash_map; local new_hm="${r}"
  30         eval local keys="\${!${hm}[@]}"
  31         for key in ${keys}; do
  32             eval val="\${${hm}[\"${key}\"]}"
  33             EVAL "${val}" "${env}"
  34             _assoc! "${new_hm}" "${key}" "${r}"
  35         done
  36         r="${new_hm}" ;;
  37     *)
  38         r="${ast}" ;;
  39     esac
  40 }
  41
  42 EVAL () {
  43     local ast="${1}" env="${2}"
  44     while true; do
  45     r=
  46     [[ "${__ERROR}" ]] && return 1
  47     #_pr_str "${ast}"; echo "EVAL '${r} / ${env}'"
  48     _obj_type "${ast}"; local ot="${r}"
  49     if [[ "${ot}" != "list" ]]; then
  50         EVAL_AST "${ast}" "${env}"
  51         return
  52     fi
  53
  54     # apply list
  55     _empty? "${ast}" && r="${ast}" && return
  56
  57     _nth "${ast}" 0; local a0="${r}"
  58     _nth "${ast}" 1; local a1="${r}"
  59     _nth "${ast}" 2; local a2="${r}"
  60     case "${ANON["${a0}"]}" in
  61         def!) EVAL "${a2}" "${env}"
  62               [[ "${__ERROR}" ]] && return 1
  63               ENV_SET "${env}" "${a1}" "${r}"
  64               return ;;
  65         let__STAR__) ENV "${env}"; local let_env="${r}"
  66               local let_pairs=(${ANON["${a1}"]})
  67               local idx=0
  68               #echo "let: [${let_pairs[*]}] for ${a2}"
  69               while [[ "${let_pairs["${idx}"]}" ]]; do
  70                   EVAL "${let_pairs[$(( idx + 1))]}" "${let_env}"
  71                   ENV_SET "${let_env}" "${let_pairs[${idx}]}" "${r}"
  72                   idx=$(( idx + 2))
  73               done
  74               ast="${a2}"
  75               env="${let_env}"
  76               # Continue loop
  77               ;;
  78         do)   _count "${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               [[ "${__ERROR}" ]] && return 1
  88               if [[ "${r}" == "${__false}" || "${r}" == "${__nil}" ]]; then
  89                   # eval false form
  90                   _nth "${ast}" 3; local a3="${r}"
  91                   if [[ "${a3}" ]]; then
  92                       ast="${a3}"
  93                   else
  94                       r="${__nil}"
  95                       return
  96                   fi
  97               else
  98                   # eval true condition
  99                   ast="${a2}"
 100               fi
 101               # Continue loop
 102               ;;
 103         fn__STAR__)  _function "ENV \"${env}\" \"${a1}\" \"\${@}\"; \
 104                          EVAL \"${a2}\" \"\${r}\"" \
 105                         "${a2}" "${env}" "${a1}"
 106               return ;;
 107         *)    EVAL_AST "${ast}" "${env}"
 108               [[ "${__ERROR}" ]] && r= && return 1
 109               local el="${r}"
 110               _first "${el}"; local f="${ANON["${r}"]}"
 111               _rest "${el}"; local args="${ANON["${r}"]}"
 112               #echo "invoke: [${f}] ${args}"
 113               if [[ "${f//@/ }" != "${f}" ]]; then
 114                   set -- ${f//@/ }
 115                   ast="${2}"
 116                   ENV "${3}" "${4}" ${args}
 117                   env="${r}"
 118               else
 119                   eval ${f%%@*} ${args}
 120                   return
 121               fi
 122               # Continue loop
 123               ;;
 124     esac
 125     done
 126 }
 127
 128 # print
 129 PRINT () {
 130     if [[ "${__ERROR}" ]]; then
 131         _pr_str "${__ERROR}" yes
 132         r="Error: ${r}"
 133         __ERROR=
 134     else
 135         _pr_str "${1}" yes
 136     fi
 137 }
 138
 139 # repl
 140 ENV; REPL_ENV="${r}"
 141 REP () {
 142     r=
 143     READ "${1}"
 144     EVAL "${r}" "${REPL_ENV}"
 145     PRINT "${r}"
 146 }
 147
 148 # core.sh: defined using bash
 149 _fref () {
 150     _symbol "${1}"; local sym="${r}"
 151     _function "${2} \"\${@}\""
 152     ENV_SET "${REPL_ENV}" "${sym}" "${r}"
 153 }
 154 for n in "${!core_ns[@]}"; do _fref "${n}" "${core_ns["${n}"]}"; done
 155 _eval () { EVAL "${1}" "${REPL_ENV}"; }
 156 _fref "eval" _eval
 157 _list; argv="${r}"
 158 for _arg in "${@:2}"; do _string "${_arg}"; _conj! "${argv}" "${r}"; done
 159 _symbol "__STAR__ARGV__STAR__"
 160 ENV_SET "${REPL_ENV}" "${r}" "${argv}";
 161
 162 # core.mal: defined using the language itself
 163 REP "(def! not (fn* (a) (if a false true)))"
 164 REP "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))"
 165
 166 # load/run file from command line (then exit)
 167 if [[ "${1}" ]]; then
 168     REP "(load-file \"${1}\")"
 169     exit 0
 170 fi
 171
 172 # repl loop
 173 while true; do
 174     READLINE "user> " || exit "$?"
 175     [[ "${r}" ]] && REP "${r}" && echo "${r}"
 176 done