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J.7 At Clauses
Syntax
1
at_clause
::= for direct_name use at expression;
Static Semantics
2
An at_clause
of the form ``for x use at y;'' is equivalent to an attribute_definition_clause
of the form ``for x'Address use y;''.
2.a
Reason: The preferred syntax
for specifying the address of an entity is an attribute_definition_clause
specifying the Address attribute. Therefore, the special-purpose at_clause
syntax is now obsolete.
2.b
The above equivalence implies,
for example, that only one at_clause
is allowed for a given entity. Similarly, it is illegal to give both
an at_clause and an attribute_definition_clause
specifying the Address attribute.
Extensions to Ada 83
2.c
{extensions to Ada 83}
We now allow to define the address of an entity using
an attribute_definition_clause.
This is because Ada 83's at_clause
is so hard to remember: programmers often tend to write ``for X'Address
use...;''.
Wording Changes from Ada 83
2.d
Ada 83's address_clause
is now called an at_clause to avoid
confusion with the new term ``Address clause'' (that is, an attribute_definition_clause
for the Address attribute).
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