Names
Author: JTC1/SC22/WG9/ARG, by Randall Brukardt, ARG Editor

Ada Reference Manual — Legal Information

# 4.1 Names

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Names can denote declared entities, whether declared explicitly or implicitly (see 3.1). Names can also denote objects or subprograms designated by access values; the results of type_conversions or function_calls; subcomponents and slices of objects and values; protected subprograms, single entries, entry families, and entries in families of entries. Finally, names can denote attributes of any of the foregoing.

#### Syntax

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name ::=
direct_name | explicit_dereference
| indexed_component | slice
| selected_component | attribute_reference
| type_conversion | function_call
| character_literal
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direct_name ::= identifier | operator_symbol
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prefix ::= name | implicit_dereference
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explicit_dereference ::= name.all
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implicit_dereference ::= name
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Certain forms of name (indexed_components, selected_components, slices, and attribute_references) include a prefix that is either itself a name that denotes some related entity, or an implicit_dereference of an access value that designates some related entity.

#### Name Resolution Rules

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The name in a dereference (either an implicit_dereference or an explicit_dereference) is expected to be of any access type.

#### Static Semantics

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If the type of the name in a dereference is some access-to-object type T, then the dereference denotes a view of an object, the nominal subtype of the view being the designated subtype of T.
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If the type of the name in a dereference is some access-to-subprogram type S, then the dereference denotes a view of a subprogram, the profile of the view being the designated profile of S.

#### Dynamic Semantics

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The evaluation of a name determines the entity denoted by the name. This evaluation has no other effect for a name that is a direct_name or a character_literal.
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The evaluation of a name that has a prefix includes the evaluation of the prefix. The evaluation of a prefix consists of the evaluation of the name or the implicit_dereference. The prefix denotes the entity denoted by the name or the implicit_dereference.
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The evaluation of a dereference consists of the evaluation of the name and the determination of the object or subprogram that is designated by the value of the name. A check is made that the value of the name is not the null access value. Constraint_Error is raised if this check fails. The dereference denotes the object or subprogram designated by the value of the name.

#### Examples

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Examples of direct names:
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Pi -- the direct name of a number (see 3.3.2)
Limit -- the direct name of a constant (see 3.3.1)
Count -- the direct name of a scalar variable (see 3.3.1)
Board -- the direct name of an array variable (see 3.6.1)
Matrix -- the direct name of a type (see 3.6)
Random -- the direct name of a function (see 6.1)
Error -- the direct name of an exception (see 11.1)
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Examples of dereferences:
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Next_Car.all -- explicit dereference denoting the object designated by
-- the access variable Next_Car (see 3.10.1)
Next_Car.Owner -- selected component with implicit dereference;
-- same as Next_Car.all.Owner

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