2.3.1 Integer Type

The range of values for integers in Emacs Lisp is -134217728 to 134217727 (28 bits; i.e., -2**27 to 2**27 - 1) on most machines. (Some machines may provide a wider range.) It is important to note that the Emacs Lisp arithmetic functions do not check for overflow. Thus (1+ 134217727) is -134217728 on most machines.

The read syntax for integers is a sequence of (base ten) digits with an optional sign at the beginning and an optional period at the end. The printed representation produced by the Lisp interpreter never has a leading `+' or a final `.'.

-1 ; The integer -1. 1 ; The integer 1. 1. ; Also the integer 1. +1 ; Also the integer 1. 268435457 ; Also the integer 1 on a 28-bit implementation.

See section 3. Numbers, for more information.