F.1 Machine_Radix Attribute Definition Clause
Static Semantics
1
{specifiable (of
Machine_Radix for decimal first subtypes) [partial]} {Machine_Radix
clause} Machine_Radix may be specified
for a decimal first subtype (see
3.5.9) via
an
attribute_definition_clause; the expression
of such a clause shall be static, and its value shall be 2 or 10. A value
of 2 implies a binary base range; a value of 10 implies a decimal base
range.
1.a
Ramification: In the absence of a Machine_Radix
clause, the choice of 2 versus 10 for S'Machine_Radix is not specified.
Implementation Advice
2
Packed decimal should be used as the internal representation
for objects of subtype S when S'Machine_Radix = 10.
2.a/2
Implementation Advice:
Packed decimal should be used as the
internal representation for objects of subtype S when S'Machine_Radix
= 10.
2.b
Discussion: The intent of a decimal Machine_Radix
attribute definition clause is to allow the programmer to declare an
Ada decimal data object whose representation matches a particular COBOL
implementation's representation of packed decimal items. The Ada object
may then be passed to an interfaced COBOL program that takes a packed
decimal data item as a parameter, assuming that convention COBOL has
been specified for the Ada object's type in a pragma
Convention.
2.c
Additionally, the Ada compiler may choose to
generate arithmetic instructions that exploit the packed decimal representation.
Examples
3
Example of Machine_Radix
attribute definition clause:
4
type Money is delta 0.01 digits 15;
for Money'Machine_Radix use 10;
Sponsored by Ada-Europe