File URI (was RE: FileDirectory>>fileExists: (was: Re: [BUG]Unable
to load BFAV, various problems ))
russell.penney at tincanct.com
Wed Apr 28 10:01:27 UTC 2004
Sorry Goran, but I really don't agree.
> Here is an excerpt from 1738:
> A file URL takes the form:
> where <host> is the fully qualified domain name of the system on
> which the <path> is accessible, and <path> is a hierarchical
> directory path of the form <directory>/<directory>/.../<name>.
And another excerpt from 1738:
2.3 Hierarchical schemes and relative links
In some cases, URLs are used to locate resources that contain
pointers to other resources. In some cases, those pointers are
represented as relative links where the expression of the location of
the second resource is in terms of "in the same place as this one
except with the following relative path". Relative links are not
described in this document. However, the use of relative links
depends on the original URL containing a hierarchical structure
against which the relative link is based.
Some URL schemes (such as the ftp, http, and file schemes) contain
names that can be considered hierarchical; the components of the
hierarchy are separated by "/".
And from 2396:
1.4. Hierarchical URI and Relative Forms
An absolute identifier refers to a resource independent of the
context in which the identifier is used. In contrast, a relative
identifier refers to a resource by describing the difference within a
hierarchical namespace between the current context and an absolute
identifier of the resource.
Some URI schemes support a hierarchical naming system, where the
hierarchy of the name is denoted by a "/" delimiter separating the
components in the scheme. This document defines a scheme-independent
`relative' form of URI reference that can be used in conjunction with
a `base' URI (of a hierarchical scheme) to produce another URI. The
syntax of hierarchical URI is described in Section 3; the relative
URI calculation is described in Section 5.
> So what did I mean? :) Well, I think I meant that a *file URL* is "a
> weird thing" that can't really be treated in practice based on the RFCs
> for URIs. The tools do lots of "smart things" in order to handle a whole
> range of false file URLs.
I don't think a *file URL* is a weird thing but something that is
translatable to all file systems (and I do mean all, the examples in the RFC
are for a VAX system!). Also there is nothing stopping Squeak defining a new
scheme for mac files or unix files or zip files. Any scheme name that starts
with "x-" is considered experimental.
More information about the Squeak-dev