[REBOL] exists?

[lmecir]

Hi, Rebols,

I know, that it has been discussed, but I think, that the
following improvement to Core Exists? may be useful.
Any suggestions are welcome.

Regards,
    Ladislav

exists?: func [
    {
        Determines if a file or URL exists.

        Checks for invalid HTML pages.
    }
    target [file! url!]
    /local port comp ts
][
    if error? try [
            port: make port! target
            query port
    ] [return false]
    if not port/status [return false]
    if port/scheme = 'HTTP [
        ts: to string! target
        if (to string! port/url) = ts [
            return true
        ]
        comp: copy "http://"
        if port/host [append comp port/host]
        if comp = ts [
            return true
        ]
        if (append copy comp #"/") = ts [
            return true
        ]
        if port/path [append comp port/path]
        if comp = ts [
            return true
        ]
        if port/target [append comp port/target]
        if comp = ts [
            return true
        ]
        return false
    ]
    true
]