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From: alex@LAGUNA.METAPHOR.COM (Bob Alexander)
Newsgroups: comp.lang.icon
Subject: Comment on longstr.icn
Message-ID: <9103200028.AA02704@laguna.Metaphor.COM>
Date: 20 Mar 91 00:28:02 GMT
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Gee, this is fun.  I have a couple of comments to throw into the frey.

1)  Perhaps instead of the stop() if there is a problem with the
arguments, a runerr() would be more consistent with the builtin
string-analysis procedures -- "115: list, set, or table expected" would
be reasonably appropriate, since the algorithm could work with tables
too (records, too, for that matter, but that's probably a bit much).

2)  Things could be simplified quite a bit by not messing with defaults
for s, i, and j and letting Icon do the work by eliminating the string
scanning.  In this version, the m := -1 initial value can revert back
to 0, since matching an empty string returns 1.

So here's my entry in the series of suggestions.  Somehow I can't help
but wonder if I've missed something obvious -- but if not, do I get my
name in the growing list of credits? :-)


procedure longstr(l,s,i,j)

    local m

    #
    # Is l a list, set, table?
    #
    type(l) == ("list" | "set" | "table") |
        runerr(115,l)

    #
    # Find longest match()-ing string in l.
    #
    m := 0                      # Attempt to match() each member in l (=!l).
    every m <:= match(!l,s,i,j) # Produce the length of each match that suc-
                                # ceeds, and store its value in m iff it is
                                # greater than m's current value.
    #
    # Return i + the length of the longest match.  Fail if there was
    # no match (i.e. m still has its original value).
    #
    return 0 ~= m

end


-- Bob Alexander

Metaphor Computer Systems   (415) 961-3600 x751   alex@metaphor.com
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