module/ice-9/eval-string.scm

   1 ;;; Evaluating code from users
   2
   3 ;;; Copyright (C) 2011, 2013 Free Software Foundation, Inc.
   4
   5 ;;;; This library is free software; you can redistribute it and/or
   6 ;;;; modify it under the terms of the GNU Lesser General Public
   7 ;;;; License as published by the Free Software Foundation; either
   8 ;;;; version 3 of the License, or (at your option) any later version.
   9 ;;;;
  10 ;;;; This library is distributed in the hope that it will be useful,
  11 ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 ;;;; Lesser General Public License for more details.
  14 ;;;;
  15 ;;;; You should have received a copy of the GNU Lesser General Public
  16 ;;;; License along with this library; if not, write to the Free Software
  17 ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18
  19 ;;; Code:
  20
  21 (define-module (ice-9 eval-string)
  22   #:use-module (system base compile)
  23   #:use-module (system base language)
  24   #:use-module (system vm program)
  25   #:replace (eval-string))
  26
  27 (define (ensure-language x)
  28   (if (language? x)
  29       x
  30       (lookup-language x)))
  31
  32 (define* (read-and-eval port #:key (lang (current-language)))
  33   (parameterize ((current-language (ensure-language lang)))
  34     (define (read)
  35       ((language-reader (current-language)) port (current-module)))
  36     (define (eval exp)
  37       ((language-evaluator (current-language)) exp (current-module)))
  38
  39     (let ((exp (read)))
  40       (if (eof-object? exp)
  41           ;; The behavior of read-and-compile and of the old
  42           ;; eval-string.
  43           *unspecified*
  44           (let lp ((exp exp))
  45             (call-with-values
  46                 (lambda () (eval exp))
  47               (lambda vals
  48                 (let ((next (read)))
  49                   (cond
  50                    ((eof-object? next)
  51                     (apply values vals))
  52                    (else
  53                     (lp next)))))))))))
  54
  55 (define* (eval-string str #:key
  56                       (module (current-module))
  57                       (file #f)
  58                       (line #f)
  59                       (column #f)
  60                       (lang (current-language))
  61                       (compile? #f))
  62   (define (maybe-with-module module thunk)
  63     (if module
  64         (save-module-excursion
  65          (lambda ()
  66            (set-current-module module)
  67            (thunk)))
  68         (thunk)))
  69
  70   (let ((lang (ensure-language lang)))
  71     (call-with-input-string
  72      str
  73      (lambda (port)
  74        (maybe-with-module
  75         module
  76         (lambda ()
  77           (if module
  78               (set-current-module module))
  79           (if file
  80               (set-port-filename! port file))
  81           (if line
  82               (set-port-line! port line))
  83           (if column
  84               (set-port-column! port line))
  85
  86           (if (or compile? (not (language-evaluator lang)))
  87               ((make-program (read-and-compile port #:from lang #:to 'objcode)))
  88               (read-and-eval port #:lang lang))))))))