Rascal Language ReferenceDeclarationsSyntax DefinitionDisambiguationReserve DeclarationOn this pageReserve Declarationrascal-1.0-SNAPSHOTSynopsisReserve is a conditional Symbol, constraining the set of strings that a symbol may produce.SyntaxSymbol \ constraintwhere a constraint is any character class, a literal or a keyword non-terminal Symbol.