display of true closures

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

Hello PARI-dev,

I have changed the way closures are displayed in SVN revision 12759.

Let
? convol(f,g)=(n->sum(k=0,n,f(n-k)*g(k)))
%1 = (f,g)->n->sum(k=0,n,f(n-k)*g(k))

before:

? convol(a,b)
%2 = (n)->sum(k=0,n,f(n-k)*g(k))

(the information about the value of f and was not printed)
now:

? convol(a,b)
%2 = (n)->my(f=a,g=b);sum(k=0,n,f(n-k)*g(k))

This has two advantages:
First it documently clearly how closures work with gp and in particular why
a() always return 1 in the following example do not work
iter()=my(x=0);()->x++
a=iter();
a()
a()

Secondly, it is now safe to copy-paste a closure or to write it to a text file, since
no information is lost.

I like to thanks Maximilian Hasler for bringing this issue.

Cheers,
Bill