sexp.lisp: Option to omit a specific package prefix

[Ambrevar]

The symbol package prefix can get really verbose at times, it'd be nice to have an option to omit it.

For instance

(export '*local*)
(defvar *local-package* nil
  "If `*local-package*' designates a package instance, don't print the package
  prefix of its symbols.")

(defun print-symbol (symbol stream)
  (let ((package (symbol-package symbol))
	(name (prin1-to-string symbol)))
    (cond ((eq package +cl-package+) (write-string "CL:" stream))
	  ((eq package +keyword-package+) (write-char #\: stream))
          ((eq package *local-package*)
           ;; Don't print the package prefix.
           nil)
	  (package (s-xml:print-string-xml (package-name package) stream)
                   (write-string "::" stream))
          (t (write-string "#:" stream)))
    (if (char= (char name (1- (length name))) #\|)
        (write-string name stream :start (position #\| name))
      (write-string name stream :start (1+ (or (position #\: name :from-end t) -1))))))

[svetlyak40wt]

Package prefix needed to deserialize the symbol propertly.

[Ambrevar]

But not if they are in the current package :)

[svetlyak40wt]

It is hard to predict which package will be current when you'll restore the data. Prevalence's format is not designed to be readable by humans.

[Ambrevar]

Alexander Artemenko <notifications@github.com> writes:

It is hard to predict which package will be current when you'll restore the data.

But you can control it, so it's a nice option to have.

Prevalence's format is not designed to be readable by humans.

The s-exp format is actually very readable ;)