Syntax Summary

{syntax (complete listing)} {grammar (complete listing)} {context free grammar (complete listing)} {BNF (Backus-Naur Form) (complete listing)} {Backus-Naur Form (BNF) (complete listing)} This Annex summarizes the complete syntax of the language. See 1.1.4 for a description of the notation used.

2.1:
character ::= graphic_character | format_effector | other_control_function

2.1:
graphic_character ::= identifier_letter | digit | space_character | special_character

2.3:
identifier ::=
identifier_start {identifier_start | identifier_extend} identifier_letter {[underline] letter_or_digit}

2.3:
identifier_extend ::=
     mark_non_spacing
   | mark_spacing_combining
   | number_decimal
   | punctuation_connector
   | other_format

2.4:
numeric_literal ::= decimal_literal | based_literal

2.4.1:
decimal_literal ::= numeral [.numeral] [exponent]

2.4.1:
numeral ::= digit {[underline] digit}

2.4.1:
exponent ::= E [+] numeral | E – numeral

2.4.1:
digit ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

2.4.2:
based_literal ::=
base # based_numeral [.based_numeral] # [exponent]

2.4.2:
base ::= numeral

2.4.2:
based_numeral ::=
extended_digit {[underline] extended_digit}

2.4.2:
extended_digit ::= digit | A | B | C | D | E | F

2.5:
character_literal ::= 'graphic_character'

2.6:
string_literal ::= "{string_element}"

2.6:
string_element ::= "" | non_quotation_mark_graphic_character

2.7:
comment ::= --{non_end_of_line_character}

2.8:
pragma ::=
pragma identifier [(pragma_argument_association {, pragma_argument_association})];

2.8:
pragma_argument_association ::=
[pragma_argument_identifier =>] name
| [pragma_argument_identifier =>] expression

3.1:
defining_identifier ::= identifier

3.2.1:
type_declaration ::=  full_type_declaration
   | incomplete_type_declaration
   | private_type_declaration
   | private_extension_declaration

3.2.1:
full_type_declaration ::=
     type defining_identifier [known_discriminant_part] is type_definition;
   | task_type_declaration
   | protected_type_declaration

3.2.2:
subtype_declaration ::=
subtype defining_identifier is subtype_indication;

3.2.2:
subtype_indication ::= [null_exclusion] subtype_mark [constraint]

3.2.2:
subtype_mark ::= subtype_name

3.2.2:
constraint ::= scalar_constraint | composite_constraint

3.2.2:
scalar_constraint ::=
range_constraint | digits_constraint | delta_constraint

3.2.2:
composite_constraint ::=
index_constraint | discriminant_constraint

3.3.1:
object_declaration ::=
    defining_identifier_list : [aliased] [constant] subtype_indication [:= expression];
  | defining_identifier_list : [aliased] [constant] access_definition [:= expression];
  | defining_identifier_list : [aliased] [constant] array_type_definition [:= expression];
  | single_task_declaration
  | single_protected_declaration

3.3.1:
defining_identifier_list ::=
defining_identifier {, defining_identifier}

3.3.2:
number_declaration ::=
defining_identifier_list : constant := static_expression;

3.4:
derived_type_definition ::=
[abstract] [limited] new parent_subtype_indication [[and interface_list] record_extension_part]

3.5:
range_constraint ::= range range

3.5:
range ::= range_attribute_reference
| simple_expression .. simple_expression

3.5.1:
enumeration_type_definition ::=
(enumeration_literal_specification {, enumeration_literal_specification})

3.5.1:
enumeration_literal_specification ::= defining_identifier | defining_character_literal

3.5.1:
defining_character_literal ::= character_literal

3.5.4:
integer_type_definition ::= signed_integer_type_definition | modular_type_definition

3.5.4:
signed_integer_type_definition ::= range static_simple_expression .. static_simple_expression

3.5.4:
modular_type_definition ::= mod static_expression

3.5.6:
real_type_definition ::=
floating_point_definition | fixed_point_definition

3.5.7:
floating_point_definition ::=
digits static_expression [real_range_specification]

3.5.7:
real_range_specification ::=
range static_simple_expression .. static_simple_expression

3.5.9:
fixed_point_definition ::= ordinary_fixed_point_definition | decimal_fixed_point_definition

3.5.9:
ordinary_fixed_point_definition ::=
delta static_expression real_range_specification

3.5.9:
decimal_fixed_point_definition ::=
delta static_expression digits static_expression [real_range_specification]

3.5.9:
digits_constraint ::=
digits static_expression [range_constraint]

3.6:
array_type_definition ::=
unconstrained_array_definition | constrained_array_definition

3.6:
unconstrained_array_definition ::=
array(index_subtype_definition {, index_subtype_definition}) of component_definition

3.6:
index_subtype_definition ::= subtype_mark range <>

3.6:
constrained_array_definition ::=
array (discrete_subtype_definition {, discrete_subtype_definition}) of component_definition

3.6:
discrete_subtype_definition ::= discrete_subtype_indication | range

3.6:
component_definition ::=
[aliased] subtype_indication
| [aliased] access_definition

3.6.1:
index_constraint ::= (discrete_range {, discrete_range})

3.6.1:
discrete_range ::= discrete_subtype_indication | range

3.7:
discriminant_part ::= unknown_discriminant_part | known_discriminant_part

3.7:
unknown_discriminant_part ::= (<>)

3.7:
known_discriminant_part ::=
(discriminant_specification {; discriminant_specification})

3.7:
discriminant_specification ::=
defining_identifier_list : [null_exclusion] subtype_mark [:= default_expression]
| defining_identifier_list : access_definition [:= default_expression]

3.7:
default_expression ::= expression

3.7.1:
discriminant_constraint ::=
(discriminant_association {, discriminant_association})

3.7.1:
discriminant_association ::=
[discriminant_selector_name {| discriminant_selector_name} =>] expression

3.8:
record_type_definition ::= [[abstract] tagged] [limited] record_definition

3.8:
record_definition ::=
    record
       component_list
    end record
  | null record

3.8:
component_list ::=
      component_item {component_item}
   | {component_item} variant_part
   |  null;

3.8:
component_item ::= component_declaration | aspect_clause representation_clause

3.8:
component_declaration ::=
defining_identifier_list : component_definition [:= default_expression];

3.8.1:
variant_part ::=
   case discriminant_direct_name is
       variant
      {variant}
   end case;

3.8.1:
variant ::=
when discrete_choice_list =>
component_list

3.8.1:
discrete_choice_list ::= discrete_choice {| discrete_choice}

3.8.1:
discrete_choice ::= expression | discrete_range | others

3.9.1:
record_extension_part ::= with record_definition

3.9.3:
abstract_subprogram_declaration ::=
[overriding_indicator]
subprogram_specification is abstract;

3.9.4:
interface_type_definition ::=
[limited | task | protected | synchronized] interface [and interface_list]

3.9.4:
interface_list ::= interface_subtype_mark {and interface_subtype_mark}

3.10:
access_type_definition ::=
[null_exclusion] access_to_object_definition
| [null_exclusion] access_to_subprogram_definition

3.10:
access_to_object_definition ::=
access [general_access_modifier] subtype_indication

3.10:
general_access_modifier ::= all | constant

3.10:
access_to_subprogram_definition ::=
access [protected] procedure parameter_profile
| access [protected] function parameter_and_result_profile

3.10:
null_exclusion ::= not null

3.10:
access_definition ::=
    [null_exclusion] access [constant] subtype_mark
  | [null_exclusion] access [protected] procedure parameter_profile
  | [null_exclusion] access [protected] function parameter_and_result_profile access subtype_mark

3.10.1:
incomplete_type_declaration ::= type defining_identifier [discriminant_part] [is tagged];

3.11:
declarative_part ::= {declarative_item}

3.11:
declarative_item ::=
basic_declarative_item | body

3.11:
basic_declarative_item ::=
basic_declaration | aspect_clause representation_clause | use_clause

3.11:
body ::= proper_body | body_stub

3.11:
proper_body ::=
subprogram_body | package_body | task_body | protected_body

4.1:
direct_name ::= identifier | operator_symbol

4.1:
prefix ::= name | implicit_dereference

4.1:
explicit_dereference ::= name.all

4.1:
implicit_dereference ::= name

4.1.1:
indexed_component ::= prefix(expression {, expression})

4.1.2:
slice ::= prefix(discrete_range)

4.1.3:
selected_component ::= prefix . selector_name

4.1.3:
selector_name ::= identifier | character_literal | operator_symbol

4.1.4:
attribute_reference ::= prefix'attribute_designator

4.1.4:
attribute_designator ::=
identifier[(static_expression)]
| Access | Delta | Digits

4.1.4:
range_attribute_reference ::= prefix'range_attribute_designator

4.1.4:
range_attribute_designator ::= Range[(static_expression)]

4.3:
aggregate ::= record_aggregate | extension_aggregate | array_aggregate

4.3.1:
record_aggregate ::= (record_component_association_list)

4.3.1:
record_component_association_list ::=
record_component_association {, record_component_association}
| null record

4.3.1:
record_component_association ::=
[component_choice_list =>] expression
| component_choice_list => <>

4.3.1:
component_choice_list ::=
component_selector_name {| component_selector_name}
| others

4.3.2:
extension_aggregate ::=
(ancestor_part with record_component_association_list)

4.3.2:
ancestor_part ::= expression | subtype_mark

4.3.3:
array_aggregate ::=
positional_array_aggregate | named_array_aggregate

4.3.3:
positional_array_aggregate ::=
    (expression, expression {, expression})
  | (expression {, expression}, others => expression)
  | (expression {, expression}, others => <>)

4.3.3:
named_array_aggregate ::=
(array_component_association {, array_component_association})

4.3.3:
array_component_association ::=
discrete_choice_list => expression
| discrete_choice_list => <>

4.4:
expression ::=
     relation {and relation}  | relation {and then relation}
   | relation {or relation}  | relation {or else relation}
   | relation {xor relation}

4.4:
relation ::=
     simple_expression [relational_operator simple_expression]
   | simple_expression [not] in range
   | simple_expression [not] in subtype_mark

4.4:
simple_expression ::= [unary_adding_operator] term {binary_adding_operator term}

4.4:
term ::= factor {multiplying_operator factor}

4.4:
factor ::= primary [** primary] | abs primary | not primary

4.5:
logical_operator ::= and | or | xor

4.5:
relational_operator ::= = | /= | < | <= | > | >=

4.5:
binary_adding_operator ::= + | – | &

4.5:
unary_adding_operator ::= + | –

4.5:
multiplying_operator ::= * | / | mod | rem

4.5:
highest_precedence_operator ::= ** | abs | not

4.6:
type_conversion ::=
subtype_mark(expression)
| subtype_mark(name)

4.7:
qualified_expression ::=
subtype_mark'(expression) | subtype_mark'aggregate

4.8:
allocator ::=
new subtype_indication | new qualified_expression

5.1:
sequence_of_statements ::= statement {statement}

5.1:
statement ::=
{label} simple_statement | {label} compound_statement

5.1:
null_statement ::= null;

5.1:
label ::= <<label_statement_identifier>>

5.1:
statement_identifier ::= direct_name

5.2:
assignment_statement ::=
variable_name := expression;

5.3:
if_statement ::=
    if condition then
      sequence_of_statements
   {elsif condition then
      sequence_of_statements}
   [else
      sequence_of_statements]
    end if;

5.3:
condition ::= boolean_expression

5.4:
case_statement ::=
   case expression is
       case_statement_alternative
      {case_statement_alternative}
   end case;

5.4:
case_statement_alternative ::=
when discrete_choice_list =>
sequence_of_statements

5.5:
loop_statement ::=
   [loop_statement_identifier:]
      [iteration_scheme] loop
         sequence_of_statements
       end loop [loop_identifier];

5.5:
iteration_scheme ::= while condition
| for loop_parameter_specification

5.5:
loop_parameter_specification ::=
defining_identifier in [reverse] discrete_subtype_definition

5.6:
block_statement ::=
   [block_statement_identifier:]
       [declare
            declarative_part]
        begin
            handled_sequence_of_statements
        end [block_identifier];

5.7:
exit_statement ::=
exit [loop_name] [when condition];

5.8:
goto_statement ::= goto label_name;

6.1:
subprogram_declaration ::=
[overriding_indicator]
subprogram_specification;

6.1:
abstract_subprogram_declaration ::= subprogram_specification is abstract;

6.1:
subprogram_specification ::=
    procedure_specification
  | function_specification
    procedure defining_program_unit_name parameter_profile
  | function defining_designator parameter_and_result_profile

6.1:
procedure_specification ::= procedure defining_program_unit_name parameter_profile

6.1:
function_specification ::= function defining_designator parameter_and_result_profile

6.1:
designator ::= [parent_unit_name . ]identifier | operator_symbol

6.1:
defining_designator ::= defining_program_unit_name | defining_operator_symbol

6.1:
defining_program_unit_name ::= [parent_unit_name . ]defining_identifier

6.1:
operator_symbol ::= string_literal

6.1:
defining_operator_symbol ::= operator_symbol

6.1:
parameter_profile ::= [formal_part]

6.1:
parameter_and_result_profile ::=
[formal_part] return [null_exclusion] subtype_mark
| [formal_part] return access_definition

6.1:
formal_part ::=
(parameter_specification {; parameter_specification})

6.1:
parameter_specification ::=
defining_identifier_list : mode [null_exclusion] subtype_mark [:= default_expression]
| defining_identifier_list : access_definition [:= default_expression]

6.1:
mode ::= [in] | in out | out

6.3:
subprogram_body ::=
    [overriding_indicator]
    subprogram_specification is
       declarative_part
    begin
        handled_sequence_of_statements
    end [designator];

6.4:
procedure_call_statement ::=
procedure_name;
| procedure_prefix actual_parameter_part;

6.4:
function_call ::=
function_name
| function_prefix actual_parameter_part

6.4:
actual_parameter_part ::=
(parameter_association {, parameter_association})

6.4:
parameter_association ::=
[formal_parameter_selector_name =>] explicit_actual_parameter

6.4:
explicit_actual_parameter ::= expression | variable_name

6.5:
simple_return_statement return_statement ::= return [expression];

6.5:
extended_return_statement ::=
    return defining_identifier : [aliased] return_subtype_indication [:= expression] [do
        handled_sequence_of_statements
    end return];

6.5:
return_subtype_indication ::= subtype_indication | access_definition

6.7:
null_procedure_declaration ::=
[overriding_indicator]
procedure_specification is null;

7.1:
package_declaration ::= package_specification;

7.1:
package_specification ::=
    package defining_program_unit_name is
      {basic_declarative_item}
   [private
      {basic_declarative_item}]
    end [[parent_unit_name.]identifier]

7.2:
package_body ::=
    package body defining_program_unit_name is
       declarative_part
   [begin
        handled_sequence_of_statements]
    end [[parent_unit_name.]identifier];

7.3:
private_type_declaration ::=
type defining_identifier [discriminant_part] is [[abstract] tagged] [limited] private;

7.3:
private_extension_declaration ::=
   type defining_identifier [discriminant_part] is
     [abstract] [limited | synchronized] new ancestor_subtype_indication
     [and interface_list] with private;

8.3.1:
overriding_indicator ::= [not] overriding

8.4:
use_clause ::= use_package_clause | use_type_clause

8.4:
use_package_clause ::= use package_name {, package_name};

8.4:
use_type_clause ::= use type subtype_mark {, subtype_mark};

8.5:
renaming_declaration ::=
      object_renaming_declaration
    | exception_renaming_declaration
    | package_renaming_declaration
    | subprogram_renaming_declaration
    | generic_renaming_declaration

8.5.1:
object_renaming_declaration ::=
defining_identifier : [null_exclusion] subtype_mark renames object_name;
| defining_identifier : access_definition renames object_name;

8.5.2:
exception_renaming_declaration ::= defining_identifier : exception renames exception_name;

8.5.3:
package_renaming_declaration ::= package defining_program_unit_name renames package_name;

8.5.4:
subprogram_renaming_declaration ::=
[overriding_indicator]
subprogram_specification renames callable_entity_name;

8.5.5:
generic_renaming_declaration ::=
    generic package defining_program_unit_name renames generic_package_name;
  | generic procedure defining_program_unit_name renames generic_procedure_name;
  | generic function defining_program_unit_name renames generic_function_name;

9.1:
task_type_declaration ::=
   task type defining_identifier [known_discriminant_part] [is
     [new interface_list with]
     task_definition];

9.1:
single_task_declaration ::=
   task defining_identifier [is
     [new interface_list with]
     task_definition];

9.1:
task_definition ::=
     {task_item}
  [ private
     {task_item}]
  end [task_identifier]

9.1:
task_item ::= entry_declaration | aspect_clause representation_clause

9.1:
task_body ::=
   task body defining_identifier is
     declarative_part
   begin
     handled_sequence_of_statements
   end [task_identifier];

9.4:
protected_type_declaration ::=
  protected type defining_identifier [known_discriminant_part] is
     [new interface_list with]
     protected_definition;

9.4:
single_protected_declaration ::=
  protected defining_identifier is
     [new interface_list with]
     protected_definition;

9.4:
protected_definition ::=
    { protected_operation_declaration }
[ private
    { protected_element_declaration } ]
  end [protected_identifier]

9.4:
protected_operation_declaration ::= subprogram_declaration
| entry_declaration
| aspect_clause representation_clause

9.4:
protected_element_declaration ::= protected_operation_declaration
| component_declaration

9.4:
protected_body ::=
  protected body defining_identifier is
   { protected_operation_item }
  end [protected_identifier];

9.4:
protected_operation_item ::= subprogram_declaration
     | subprogram_body
     | entry_body
     | aspect_clause representation_clause

9.5.2:
entry_declaration ::=
[overriding_indicator]
entry defining_identifier [(discrete_subtype_definition)] parameter_profile;

9.5.2:
accept_statement ::=
   accept entry_direct_name [(entry_index)] parameter_profile [do
     handled_sequence_of_statements
   end [entry_identifier]];

9.5.2:
entry_index ::= expression

9.5.2:
entry_body ::=
  entry defining_identifier  entry_body_formal_part  entry_barrier is
    declarative_part
  begin
    handled_sequence_of_statements
  end [entry_identifier];

9.5.2:
entry_body_formal_part ::= [(entry_index_specification)] parameter_profile

9.5.2:
entry_barrier ::= when condition

9.5.2:
entry_index_specification ::= for defining_identifier in discrete_subtype_definition

9.5.3:
entry_call_statement ::= entry_name [actual_parameter_part];

9.5.4:
requeue_statement ::= requeue entry_name [with abort];

9.6:
delay_statement ::= delay_until_statement | delay_relative_statement

9.6:
delay_until_statement ::= delay until delay_expression;

9.6:
delay_relative_statement ::= delay delay_expression;

9.7:
select_statement ::=
   selective_accept
  | timed_entry_call
  | conditional_entry_call
  | asynchronous_select

9.7.1:
selective_accept ::=
  select
   [guard]
     select_alternative
{ or
   [guard]
     select_alternative }
[ else
   sequence_of_statements ]
  end select;

9.7.1:
guard ::= when condition =>

9.7.1:
select_alternative ::=
   accept_alternative
  | delay_alternative
  | terminate_alternative

9.7.1:
accept_alternative ::=
accept_statement [sequence_of_statements]

9.7.1:
delay_alternative ::=
delay_statement [sequence_of_statements]

9.7.1:
terminate_alternative ::= terminate;

9.7.2:
timed_entry_call ::=
  select
   entry_call_alternative
  or
   delay_alternative
  end select;

9.7.2:
entry_call_alternative ::=
procedure_or_entry_call entry_call_statement [sequence_of_statements]

9.7.2:
procedure_or_entry_call ::=
procedure_call_statement | entry_call_statement

9.7.3:
conditional_entry_call ::=
  select
   entry_call_alternative
  else
   sequence_of_statements
  end select;

9.7.4:
asynchronous_select ::=
  select
   triggering_alternative
  then abort
   abortable_part
  end select;

9.7.4:
triggering_alternative ::= triggering_statement [sequence_of_statements]

9.7.4:
triggering_statement ::= procedure_or_entry_call entry_call_statement | delay_statement

9.7.4:
abortable_part ::= sequence_of_statements

9.8:
abort_statement ::= abort task_name {, task_name};

10.1.1:
compilation ::= {compilation_unit}

10.1.1:
compilation_unit ::=
context_clause library_item
| context_clause subunit

10.1.1:
library_item ::= [private] library_unit_declaration
| library_unit_body
| [private] library_unit_renaming_declaration

10.1.1:
library_unit_declaration ::=
subprogram_declaration | package_declaration
| generic_declaration | generic_instantiation

10.1.1:
library_unit_renaming_declaration ::=
package_renaming_declaration
| generic_renaming_declaration
| subprogram_renaming_declaration

10.1.1:
library_unit_body ::= subprogram_body | package_body

10.1.1:
parent_unit_name ::= name

10.1.2:
context_clause ::= {context_item}

10.1.2:
context_item ::= with_clause | use_clause

10.1.2:
with_clause ::= limited_with_clause | nonlimited_with_clause with library_unit_name {, library_unit_name};

10.1.2:
limited_with_clause ::= limited [private] with library_unit_name {, library_unit_name};

10.1.2:
nonlimited_with_clause ::= [private] with library_unit_name {, library_unit_name};

10.1.3:
body_stub ::= subprogram_body_stub | package_body_stub | task_body_stub | protected_body_stub

10.1.3:
subprogram_body_stub ::=
[overriding_indicator]
subprogram_specification is separate;

10.1.3:
package_body_stub ::= package body defining_identifier is separate;

10.1.3:
task_body_stub ::= task body defining_identifier is separate;

10.1.3:
protected_body_stub ::= protected body defining_identifier is separate;

10.1.3:
subunit ::= separate (parent_unit_name) proper_body

11.1:
exception_declaration ::= defining_identifier_list : exception;

11.2:
handled_sequence_of_statements ::=
     sequence_of_statements
  [exception
     exception_handler
    {exception_handler}]

11.2:
exception_handler ::=
when [choice_parameter_specification:] exception_choice {| exception_choice} =>
sequence_of_statements

11.2:
choice_parameter_specification ::= defining_identifier

11.2:
exception_choice ::= exception_name | others

11.3:
raise_statement ::= raise;
| raise exception_name [with string_expression]; raise [exception_name];

12.1:
generic_declaration ::= generic_subprogram_declaration | generic_package_declaration

12.1:
generic_subprogram_declaration ::=
generic_formal_part subprogram_specification;

12.1:
generic_package_declaration ::=
generic_formal_part package_specification;

12.1:
generic_formal_part ::= generic {generic_formal_parameter_declaration | use_clause}

12.1:
generic_formal_parameter_declaration ::=
      formal_object_declaration
    | formal_type_declaration
    | formal_subprogram_declaration
    | formal_package_declaration

12.3:
generic_instantiation ::=
     package defining_program_unit_name is
         new generic_package_name [generic_actual_part];
   | [overriding_indicator]
     procedure defining_program_unit_name is
         new generic_procedure_name [generic_actual_part];
   | [overriding_indicator]
     function defining_designator is
         new generic_function_name [generic_actual_part];

12.3:
generic_actual_part ::=
(generic_association {, generic_association})

12.3:
generic_association ::=
[generic_formal_parameter_selector_name =>] explicit_generic_actual_parameter

Annex P

(informative)

Syntax Summary