Object-oriented Software in Ada 95

Ada introduction: Part 2 53
Note 3
Note 4
A fixed point number is effectively composed of two components: the
whole part and the fractional part stored in an integer value. This can
lead to more efficient arithmetic on a machine which does not have
floating point hardware or where the implementation of floating point
arithmetic is slow. It also provides a precise way of dealing with numbers
that have a decimal point.
An alternative notation for a decimal fixed point type is:
type Miles is delta 0.1 digits 8 range 0.0 .. 10.0;
However, even though all compilers must parse this type declaration they
only need to support it if the compiler implements the Information systems
Annex.
A floating point number.
An alternative type declaration is:
type Miles is digits 8;
which defines the precision 8 digits but not the range of values that may
be stored.
4.14.1 The inbuilt types
Ada provides the following inbuilt types.
Type Classification An instance of the type
Boolean Enumeration Holds either True or False.
Character Enumeration Holds a character based on the ISO 8859-1
character set. In which there are 256 distinct
characters.
Float Float Holds numbers which contain a decimal
place.
Integer Integer Holds whole numbers.
Wide_character Enumeration Holds a character based on the ISO 10646
BMP character set. In which there are 65536
distinct characters.
The implementation minimum values for these types are given in Section B.6, Appendix B.
4.15 Arithmetic operators
The arithmetic operators in Ada 95 are:
+ Addition
- Subtraction
* Multiplication
/ Division
The following arithmetic operators are defined on integer values only:
mod
rem
abs
Modulus
Remainder
Returns the absolute value
The operators mod and rem are similar, and will give identical results when both operands have the same sign.
The operator rem gives a remainder corresponding to the integer division operation /. The consequence of this is
that as integer division truncates towards 0, the absolute value of the result will always be the same regardless of
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