minnat

OpenTuring

minnatminimum natural number function

Syntax   minnat : nat

Description   The minnat function is used to determine the smallest natural number that can be used in a program.

Example   This program outputs the smallest natural number.

        put "The smallest natural number that can be used is ", minnat

Details   In current Turing and OOT implementations, natural numbers are stored in 4 bytes, i.e., 32 bits. However, the minimum natural number in all implementations is 0. minnat is provided for purposes of symmetry with minint, maxint and maxnat.

In four bytes it is possible to represent one more value, namely, 2**32 - 1 = 4294967295. This extra value is used in Turing to represent the uninitialized natural number. Although it can be computed, any attempt to assign it to a nat variable is detected as an overflow. You can use this extra value by using the nat4 type instead of nat, but this type has no initialization checking.

See also   minint and maxnat.

See also predefined unit Limits.