Hermes: A Tutorial and Reference Manual - Researcher - IBM

768.1.VariableNames 8.1.1BaseVariables Basevariablesaredenedwithinnamespacescalleddeclarationslists.The Examples:Foo,Foo.Bar,Foo.Bar.Baz. base{variable
pearonlywithinexecutablecode|eitherprocessmodulesorconstraint regionofvisibilityofadeclarationslistiscalleditsscope.Scopesap-
::=identier
theprogrammercandeclarebasevariables.Theselector,theinspect,the tializationportdeclarationandthebasevariablesdeclaredfollowingthe forstatement,andtheexpressionblockalsointroducescopescontaining constraintdenition. denitions.Theoutermostscopeinthiscaseisthedeclarationlistofthe declarekeyword.Theblockstatementdenesaninnerscope,inwhich asinglebasevariabledeclaration.Scopesalsoappearwithinconstraint denitions.Scopescanbenested.Inanexecutablemodule,theprocess bodyistheoutermostscope.Thedeclarationslistcomprisesthetheini-
declarationproducinga\hole"intheoutervariable'sscope.)Itispermissibleforthesameidentiertobedeclaredtwicewithinaprogramifthe
scopesdonotoverlap.Example: block Itisillegalforthesameidentiertobedenedwithintwooverlapping scopes.(Inotherlanguages,thisinnerdeclarationwould\hide"theouter
begin declare forXinT[]--illegalredeclarationofX X:integer; T:tableofintegers; inspect
withinitsscope.Becausebasevariablescannothaveoverlappingscopes, forTinZwhere(T>0)--legalredeclarationofT Theresolutionruleforbasevariablesistrivial:Abasevariableisvisible endblock; inspect endfor; callPutLine(IntToString(T)); endfor; callPutLine(IntToString(X));
variable. therecanbeamaximumofonevisibledeningoccurrenceofanybase