Ada Reference Manual (Ada 2022) — Legal Information

# 11.3 Raise Statements and Raise Expressions

1
A raise_statement raises an exception.

#### Syntax

2/2
raise_statement ::= raise;
| raise exception_name [with string_expression];
2.1/4
raise_expression ::= raise exception_name [with string_simple_expression]
2.2/4
If a raise_expression appears within the expression of one of the following contexts, the raise_expression shall appear within a pair of parentheses within the expression:
2.3/4
object_declaration;
2.4/4
modular_type_definition;
2.5/4
floating_point_definition;
2.6/4
ordinary_fixed_point_definition;
2.7/4
decimal_fixed_point_definition;
2.8/4
default_expression;
2.9/4
ancestor_part.

#### Legality Rules

3/4
The exception_name, if any, of a raise_statement or raise_expression shall denote an exception. A raise_statement with no exception_name (that is, a re-raise statement) shall be within a handler, but not within a body enclosed by that handler.

#### Name Resolution Rules

3.1/4
The string_expression or string_simple_expression, if any, of a raise_statement or raise_expression is expected to be of type String.
3.2/4
The expected type for a raise_expression shall be any single type.

#### Dynamic Semantics

4/4
To raise an exception is to raise a new occurrence of that exception, as explained in 11.4. For the execution of a raise_statement with an exception_name, the named exception is raised. Similarly, for the evaluation of a raise_expression, the named exception is raised. In both of these cases, if a string_expression or string_simple_expression is present, the expression is evaluated and its value is associated with the exception occurrence. For the execution of a re-raise statement, the exception occurrence that caused transfer of control to the innermost enclosing handler is raised again.
4.1/4
NOTE If the evaluation of a string_expression or string_simple_expression raises an exception, that exception is propagated instead of the one denoted by the exception_name of the raise_statement or raise_expression.

#### Examples

5
Examples of raise statements:
6/2
raise Ada.IO_Exceptions.Name_Error; -- see A.13
raise Queue_Error with "Buffer Full"; -- see 9.11
7
raise; -- re-raise the current exception
8/5
-- For an example of a raise expression, see the Streams Subsystem definitions in 13.13.1.

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