Node:Integers, Next:, Up:Numbers


Integers

Integers can be arbitrarily large.

A fairly complete set of operations on Integers has been implemented.

Other bases than 10 can be specified with the r prefix: 

Q1> 16rff
255
For convenience, the 0x prefix used in C is also recognized as being the same as 16r: 
Q2> 0xFF
255
But a 0 prefix does not indicate an octal number: 0177 = 177

The variable print_base controls the base used for output: 

Q3> print_base:=16
Q4> 255
FF
Q5> print_readable:=1
Q6> 255
0xFF
Q7> print_base:=8
Q8> 255
8r377

(Implementation note: Arbitrary-precision unsigned integers are implemented using the GNU Multi_Precision Package. Twos-complement integers are implemented using this package. FixInts are BigNums that fit in one word (usually, 32 bits). The most common FixInts (about -100 to +1000) are pre-allocated.)