VDM-10 Language Manual

VDM-10 Language Manual
A.9.10
A.9.11
A.9.12
Exception Handling Statements
always statement = ‘always’, statement, ‘in’, statement ;
trap statement = ‘trap’, pattern bind, ‘with’, statement,
‘in’, statement ;
recursive trap statement = ‘tixe’, traps, ‘in’, statement ;
traps = ‘{’, pattern bind, ‘|->’, statement,
{ ‘,’, pattern bind, ‘|->’, statement }, ‘}’ ;
exit statement = ‘exit’, [ expression ] ;
The Error Statement
error statement = ‘error’ ;
The Identity Statement
identity statement = ‘skip’ ;
A.10 Patterns and Bindings
A.10.1
Patterns
pattern = pattern identifier
| match value
| set enum pattern
| set union pattern
| seq enum pattern
| seq conc pattern
| tuple pattern
| record pattern ;
pattern identifier = identifier | ‘-’ ;
match value = ‘(’, expression, ‘)’
| symbolic literal ;
set enum pattern = ‘{’, [ pattern list ], ‘}’ ;
set union pattern = pattern, ‘union’, pattern ;
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