Re: keyword pairs and OPEN

[Daniel L. Weinreb <dlw at SCRC-TENEX at MIT-MC>]

    Date:  5-Oct-82 20:31:36 PDT (Tuesday)
    From: Masinter at PARC-MAXC
    :ACCESS	 - one of :INPUT, :OUTPUT, :APPEND (or ...)
	    no default

    :RECOG - one of :OLD, :NEW, :OLD/NEW (or ...)
	    default depends on :ACCESS

I don't understand this.  Please tell me what each combination means.
For example, what if access is INPUT and recog is NEW?  What if access
is OUTPUT (in the sense of create) and recog is OLD?  It is quite
important that the semantics of OPEN be clearly defined so that every
implementation can be consistent.

The existing definition of the Lisp Machine OPEN function looks rather
similar to what you are proposing; its general complexity and
overgenerality have made it incomprehensible, and so the system has
several completely misimplementations, none of which work right.
I was trying to counter this by keeping things simple and obvious.