guile/env.scm

   1 ;;  Copyright (C) 2015
   2 ;;      "Mu Lei" known as "NalaGinrut" <NalaGinrut@gmail.com>
   3 ;;  This file is free software: you can redistribute it and/or modify
   4 ;;  it under the terms of the GNU General Public License as published by
   5 ;;  the Free Software Foundation, either version 3 of the License, or
   6 ;;  (at your option) any later version.
   7
   8 ;;  This file is distributed in the hope that it will be useful,
   9 ;;  but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 ;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 ;;  GNU General Public License for more details.
  12
  13 ;;  You should have received a copy of the GNU General Public License
  14 ;;  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 (library (env)
  17   (export make-Env)
  18   (import (guile) (types)))
  19
  20 (define* (make-Env #:key (outer nil) (binds '()) (exprs '()))
  21   (define _env (make-hash-table))
  22   (define (_set k v) (hash-set! _env k v))
  23   (define (_get k)
  24     (or (hash-ref _env k) (and (not (_nil? outer)) ((outer 'find) k))))
  25   (define (_find k) (_get k))
  26   (for-each (lambda (b e) (hash-set! _env b e)) binds exprs)
  27   (lambda (cmd)
  28     (case cmd
  29       ((set) _set)
  30       ((find) _find)
  31       ((get) _get)
  32       (else (throw 'mal-error "BUG: Invalid cmd" cmd)))))