NULL-PACKAGE 1.3.4

Safe and robust S-Expression reader. Useful to read from unfailthfull stream/socket.

Alternatives and differences.

	safe-read	eclector	null-package
NIL	*	*	*
()	ERROR	*	*
Read macro	ERROR	*	*
Prefixed symbol	ERROR	Can recover	Can control
Backquote	ERROR	Its own	Impl own

NULL-PACKAGE aims to be used for static analyzing rather than security. If you want more strict one for security reason, SAFE-READ is recommended.

Usage

(with-input-from-string (s "hoge")
  (read-with-null-package s))
=> #:HOGE

For details, see spec file.

*ONLY-JUNK-P*

If NIL (the default), every symbols are uninterned. If T, only broken symbols are uninterned.

(let ((*only-junk-p* t))
  (with-input-from-string (s "(car (cdr (list a b no-such-package:c)))")
    (read-with-null-package s)))
=> (CAR (CDR (LIST A B #:C)))

*TARGET-SYMBOLS*

If *ONLY-JUNK-P* is the list of package designators, the symbol satisfies *TARGET-SYMBOLS* are only interned.

(defpackage test (:use :cl) (:export car cdr))

(let ((*terget-symbols* :external) ; The default though.
      (*only-junk-p* '(:test)))
  (with-input-from-string (s "(car (cdr (list a b no-such-package:c)))")
    (read-with-null-package s)))
=> (CAR (CDR (#:LIST #:A #:B #:C)))

Memo

In fact, ideal syntax was like below.

(let ((*package* (find-package :null)))
  (with-input-from-string (s "hoge")
    (read s)))

But there is no portable way to set default reader to readtable.

From developer

Product's goal

Already?

License

MIT

Developed with

SBCL

Tested with

• SBCL/2.1.6
• CCL/1.12
• CLISP/2.49
• ECL/20.4.24