Hermes: A Tutorial and Reference Manual - Researcher - IBM

sionisthemeetofthetypestatebeforeexecutionofthetestexpressionand thetypestateonnormalterminationoftherepeatclause.Thetypestate 9811.3.ControlFlowOperations asthetypestateafterexecutionofthetestexpression. Select onentrytotherepeatclauseisthetypestateafterexecutionofthetest expression.Thetypestateonterminationofthewhileclauseisthesame compound{statement select{clause ::=select[select{expression] endselect [select{clause]...
event{guard ::=boolean{guard[statement;]... ::=event{guardandboolean{guard[statement;]... ::=event{guard[statement;]... otherwise{clause
boolean{guard ::=eventinport{variable
Theselectstatementconsistsofanoptionalexpression,asetofselect clauses,andanotherwiseclause.Aselectclauseconsistsofaguardanda otherwise{clause select{expression ::=otherwise[statement;]... ::=where(test{expression)
clause.Aguardcanbe abooleanguard, aconjunctionofabooleanguardandaneventguardnaminganinput port,or ::=expression
eventinport1 Example: select where(x>0) aneventguardalone,whichistreatedasifabooleanguardof'true' y:=x+y; hadbeencoded.