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From: new@ee.udel.edu (Darren New)
Newsgroups: comp.lang.misc
Subject: Re: Dynamic typing (part 3)
Message-ID: <49907@nigel.ee.udel.edu>
Date: 5 Apr 91 19:01:00 GMT
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In article <28875@dime.cs.umass.edu> yodaiken@chelm.cs.umass.edu (victor yodaiken) writes:
>Your explanation is confusing me even more.
>Maybe a precise definition of "dynamic typing" would be useful.

Dynamic typing is when the type of a *variable* is unknown (and unspecified)
at compile time.  Any given value assigned to that variable will have
a type, but the variable does not restrict what types of values may
be assigned to it.  Contrast these:

int f(float f, int i) { blah blah blah }
/* here, f must only get floats and i must only get ints. */

(defun f (f i) (blah blah ))
Here, f may be a float, and integer, a bignum, a list, a closure, etc.

Basically, expressions, variables, function names, and so on do not have
types.  Nothing that is purely syntactical has types.  Only actual
values have types.               -- Darren


-- 
--- Darren New --- Grad Student --- CIS --- Univ. of Delaware ---
----- Network Protocols, Graphics, Programming Languages, FDTs -----
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