VDM-10 Language Manual

VDM-10 Language Manual
A.6.8
A.6.9
Thread Definitions (VDM++ and VDM-RT)
thread definitions = ‘thread’, [ thread definition ] ;
thread definition = periodic thread definition
| procedural thread definition ;
periodic thread definition = periodic obligation ;
periodic obligation = ‘periodic’,‘(’, numeral, numeral, numeral,
numeral, ‘)’, ‘(’, name, ‘)’ ;
procedural thread definition = statement ;
Trace Definitions
traces definitions = ‘traces’, { named trace } ;
named trace = identifier, { ‘/’, identifier }, ‘:’, trace definition list ;
trace definition list = trace definition term, { ‘;’, trace definition term } ;
trace definition term = trace definition
| trace definition term, ‘|’, trace definition ;
trace definition = trace core definition
| trace bindings, trace core definition
| trace core definition, trace repeat pattern
| trace bindings, trace core definition, trace repeat pattern ;
trace core definition = trace apply expression
| trace bracketed expression ;
trace apply expression = call statement ;
trace repeat pattern = ‘*’
| ‘+’
| ‘?’
| ‘{’, numeric literal, ‘}’
| ‘{’, numeric literal, ‘,’ numeric literal, ‘}’ ;
trace bracketed expression = ‘(’, trace definition list, ‘)’ ;
trace bindings = trace binding, { trace binding } ;
trace binding = ‘let’, local definitions, { ‘,’, local definition }, ‘in’
| ‘let’, multiple bind, ‘in’
| ‘let’, multiple bind, ‘be’, ‘st’, expression, ‘in’ ;
182