thanks

On Tue, Oct 9, 2012 at 3:36 PM, Alan Ruttenberg <alanruttenberg@gmail.com> wrote:

On Tue, Oct 9, 2012 at 2:34 PM, archisman rudra <archi.rudra@gmail.com> wrote:

Is this correct behavior?

CL-USER(17): (type-of 1234567898723618080928927362387)
(INTEGER 2147483648)

The relevant java code is in Bignum.java: (the value field is a java BigInteger)

@Override
public LispObject typeOf()
{
if (value.signum() > 0)
return list(Symbol.INTEGER,
new Bignum((long)Integer.MAX_VALUE + 1));

return Symbol.BIGNUM;
}

for comparison:
CL-USER(23): (type-of -1234567898723618080928927362387)
BIGNUM

which makes intuitive sense.
http://www.lispworks.com/documentation/lw51/CLHS/Body/f_tp_of.htm

Relevant bits of type-of description:
Returns a type specifier, typespec, for a type that has the object as an element. The typespec satisfies the following:
1. For any object that is an element of some built-in type:

a. the type returned is a recognizable subtype of that built-in type.

b. the type returned does not involve and, eql, member, not, or, satisfies, or values.

3. The type returned by type-of is always a recognizable subtype of the class returned by class-of. That is,
 (subtypep (type-of object) (class-of object)) =>  true, true
So my read is that there's no guarantee of literal repeatability between the returned values of type-of even in subsequent calls, never mind between implementations.

-Alan

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