+ resolve(stage, RESOLVE_BLOCKS|RESOLVE_TYPES|RESOLVE_VARIABLES);
+}
+
+template<typename T>
+bool Compiler::resolve(Stage &stage, unsigned &flags, unsigned bit)
+{
+ if(!(flags&bit))
+ return false;
+
+ flags &= ~bit;
+ return T().apply(stage);
+}
+
+void Compiler::resolve(Stage &stage, unsigned flags)
+{
+ while(flags)
+ {
+ if(resolve<BlockHierarchyResolver>(stage, flags, RESOLVE_BLOCKS))
+ ;
+ else if(resolve<TypeResolver>(stage, flags, RESOLVE_TYPES))
+ flags |= RESOLVE_BLOCKS|RESOLVE_VARIABLES|RESOLVE_EXPRESSIONS;
+ else if(resolve<VariableResolver>(stage, flags, RESOLVE_VARIABLES))
+ flags |= RESOLVE_EXPRESSIONS;
+ else if(resolve<FunctionResolver>(stage, flags, RESOLVE_FUNCTIONS))
+ flags |= RESOLVE_EXPRESSIONS;
+ else if(resolve<ExpressionResolver>(stage, flags, RESOLVE_EXPRESSIONS))
+ flags |= RESOLVE_VARIABLES|RESOLVE_FUNCTIONS;
+ }
+}
+
+void Compiler::validate(Stage &stage)
+{
+ DeclarationValidator().apply(stage);
+ IdentifierValidator().apply(stage);
+ ReferenceValidator().apply(stage);
+ ExpressionValidator().apply(stage);
+ FlowControlValidator().apply(stage);
+ StageInterfaceValidator().apply(stage);
+}
+
+bool Compiler::check_errors(Stage &stage)
+{
+ stable_sort(stage.diagnostics, &diagnostic_line_order);
+ return !any_of(stage.diagnostics.begin(), stage.diagnostics.end(),
+ [](const Diagnostic &d){ return d.severity==Diagnostic::ERR; });