Questions, comments and clarifications on clarifications

[Daniel L. Weinreb <DLW@SCRC-QUABBIN.ARPA>]

    Date: Mon, 16 Dec 85 13:01 EST
    From: Guy Steele <gls@THINK-AQUINAS.ARPA>

    Sorry it wasn't clean.  FILE-LENGTH is defined to return the length of a
    file measured in units of ELEMENT-TYPE.  FILE-LENGTH now is guaranteed
    to work only on an open stream, and it uses the ELEMENT-TYPE specified
    when the stream was opened.  The proposal is to allow FILE-LENGTH to
    take any pathname, but in that case it may be necessary to specify an
    ELEMENT-TYPE explicitly in order to get the answer you want.

If this is what you mean, it should be made clear that (1) the model of
a "file" is that it has a single associated element-type, and (2) if you
use the new form of file-length, and you pass in :element-type, then the
value must be the same as the actual element-type of the file, or else
it is an error (the result is undefined).

(Put more crudely, there should be no defined way to write a file in
units of X and then ask for its length in units of Y, that claims to be
portable.)