[Maxima-bugs] [ maxima-Bugs-679437 ] DEFINE documentation

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Bugs item #679437, was opened at 2003-02-03 06:52
Message generated for change (Comment added) made by macrakis
You can respond by visiting: 
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Category: Documentation
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: David Billinghurst (billingd)
Assigned to: Nobody/Anonymous (nobody)
Summary: DEFINE documentation

Initial Comment:
From 
http://www.math.utexas.edu/pipermail/maxima/2002/002
789.html

The docu says

 - Function: DEFINE (f(x1, ...), body)
     is equivalent to f(x1,...):="body but when used inside 
functions
     it happens at execution time rather than at the time 
of definition
     of the function which contains it.

Asside from the fact that " should (globally, at least also 
in
"Introduction to Command Line") be replaced by '',

define(f(x),Block([],local(f),Map(lambda([x,y],f[x]:y),
[1,3,5],[2,5,1]),f[x]));

returns
 
 f(x) := f[x]

and

f(x):=''Block([],local(f),Map(lambda([x,y],f[x]:y),[1,3,5],
[2,5,1]),f[x]);

returns

 f(x):=BLOCK([],LOCAL(f),MAP(LAMBDA([x,y],f[x]:y),
[1,3,5],[2,5,1]),f[x])

so, it seems that this is not really an equivalence. In 
fact, it seems to
me that '' doen't do anything in this context. Furthermore

g():= f(x):=''Block([],local(f),Map(lambda([x,y],f[x]:y),
[1,3,5],[2,5,1]),f[x]);

(as well as the same statement without '' ) makes g(); 
return

f(x):=BLOCK([],LOCAL(f),MAP(LAMBDA([x,y],f[x]:y),
[1,3,5],[2,5,1]),f[x])

(and now f is defined), while

g():=define(f(x),Block([],local(f),Map(lambda([x,y],f[x]:y),
[1,3,5],[2,5,1]),f[x]));

makes g(); return

f(x):=f[x]

(which is what I expected) So, I think the docu should 
say something like

 - Function: DEFINE (f(x1, ...), body)
     is equivalent to f(x1,...):=evaluated_body, where 
evaluated_body is
     the evaluation of body.



----------------------------------------------------------------------

>Comment By: Stavros Macrakis (macrakis)
Date: 2003-07-07 17:12

Message:
Logged In: YES 
user_id=588346

The problem here is that ''f(x) is not equivalent to ''(f(x)).

The documenation should say

          ...is equivalent to f(x1,...):=''(body)

Now, WHY is ''f(x) not equivalent to ''(f(x))?  Well, that is in 
my opinion a design error, but since it is documented under '', 
I suppose it can't be considered a bug.


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