14  1725 
E. Robert Tisdale wrote: Is a function an object?
Mr. Tisdale,
Please define "object". Then define "function".
If, in your definitions, a function can fit in the realm
of, in your definition, of an object, then so mote it be.
Secondly, why does it matter?
I've used functions as objects (or more precisely,
pointer to functions). I've used objects as functions
(more precisely, pointers to functions that reside in
a structure). Whether an object is a function or a
function is an object has never precluded me from
accomplishing my programming task.
I'd rather be programming than debating the philophics
of programming.
--
Thomas Matthews
C++ newsgroup welcome message: http://www.slack.net/~shiva/welcome.txt
C++ Faq: http://www.parashift.com/c++-faq-lite
C Faq: http://www.eskimo.com/~scs/c-faq/top.html
alt.comp.lang.l earn.c-c++ faq: http://www.comeaucomputing.com/learn/faq/
Other sites: http://www.josuttis.com -- C++ STL Library book
Thomas Matthews wrote: E. Robert Tisdale wrote:
Is a function an object?
Mr. Tisdale,
Please define "object".
Trollsdale posted to two newsgroups. In one of them, comp.lang.c,
"object" is defined by the standard defining the language. He knows
this. He also knows that a function is not an object in C. I have
already asked people not to get sucked into this attempt to set people
from comp.object, who have no more reason to know C than any other
language, against the people from comp.lang.c, for whom there is nothing
to discuss. *Please* don't play Trollsdale's game. If you must discuss
this boring question, set the newsgroups or at least followups to point
to your newsgroup only.
Follow-ups set to comp.lang.c
"E. Robert Tisdale" <E.************ **@jpl.nasa.gov > wrote
Is a function an object?
It comes down to semantics. In the C standard, "object" is defined as data
occupying a contiguous region of storage. However if you said "what object
does that pointer point to?" and someone replied "it's a function pointer to
printf()" most people would accept the exchange as grammatical.
In C++ you can have "function objects" which are a template-safe form of
function pointer.
In C, given approriate support, you can create data objects which specify
functions. For instance you could write a parser that calculates a function
of x and y, written in mathematical notation.
"Malcolm" <ma*****@55bank .freeserve.co.u k> writes: "E. Robert Tisdale" <E.************ **@jpl.nasa.gov > wrote
Is a function an object?
It comes down to semantics. In the C standard, "object" is defined as data
occupying a contiguous region of storage. However if you said "what object
does that pointer point to?" and someone replied "it's a function pointer to
printf()" most people would accept the exchange as grammatical.
In C++ you can have "function objects" which are a template-safe form of
function pointer.
In C, given approriate support, you can create data objects which specify
functions. For instance you could write a parser that calculates a function
of x and y, written in mathematical notation.
If you're referring to a data structure that can specify the
evaluation of some function, you can certainly do that, but it's not
strictly speaking a "function" in the C sense.
--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
Thomas Gagne <tg****@wide-open-west.com> wrote in
news:Cb******** ************@wi deopenwest.com: I like Alan's explanation. He correctly prefaces it with, "It
depends!" Functions existing as objects themselves is a powerful
concept that escapes many programmers. It is worth investigating.
Yup. I have a fairly substantial numerical methods package (originally
Smalltalk, now Java) that does function calculations, derivatives, interval
calculations, statistics, blah blah blah, where functions are objects and
practically everything else is done with the Visitor pattern.
So roughly, if you have a function that is a "one-time" thing that belongs
to another object, make it a method. But if you have a function that is
going to be used for several things, then promote it to a first-class
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