[Maxima-bugs] [ maxima-Bugs-886392 ] ('[a,b,c])[2] and ('v)[2]

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Bugs item #886392, was opened at 2004-01-28 13:34
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Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Stavros Macrakis (macrakis)
Assigned to: Nobody/Anonymous (nobody)
Summary: ('[a,b,c])[2] and ('v)[2]

Initial Comment:
arrayapply('[a,b],[2]) => b  OK
('[a,b])[2] =>
  Illegal form - SIMPLIFYA:
  ((((MLIST) |$a| |$b|)) 2)

cf bug 866706: ('m)[1] => m(2), not v[2]

What is going on here is that Maxima wants to treat

   ('f)(x) == funmake('f,[x]) == apply('('f),[x])

which I find a very poor convention, because it means 
that the (...)(...) construction is non-compositional.  
After all,

   ('f+0)(x) == apply('f,[x])

So, ... how do you explain this?  Do you consider ('...)() 
== ('(...))() to be a special *syntactic* construction, 
even though the parser doesn't parse it into any sort of 
special internal form?  Yuck, yuck, yuck.

The fact that apply('('f),...) is special-cased is less 
problematic, but still weird, since apply('('f+0),...) does 
the same thing, though apply('(factor('fff)),[x]) gives an 
error.  More yuck.

Ayway it doesn't use funmake to construct the result, 
so screws up the error.

I am not sure what the best fix is.  I am tempted to 
completely eliminate ('f)(x) and apply('('f)...) as special 
cases.  Then everything "just works".  True, you need to 
use funmake to avoid evaluating, but that should be OK.



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