"whose value is non-negative">;

def TFL_BoolTrue : AttrConstraint<
    CPred<"$_self.isa<BoolAttr>() && $_self.cast<BoolAttr>().getValue()">,
    "whose value is true">;

def TFL_BoolFalse : AttrConstraint<
    CPred<"$_self.isa<BoolAttr>() && !$_self.cast<BoolAttr>().getValue()">,
    "whose value is false">;

class TFL_StringEqualsTo<string value> : AttrConstraint<

  auto array = attr.cast<mlir::ArrayAttr>().getValue();

  for (int i = 0; i < array.size(); i++) {
    if (llvm::isa<mlir::BoolAttr>(array[i])) {
      flex_builder->Bool(name.c_str(),
                         array[i].cast<mlir::BoolAttr>().getValue());
    } else if (llvm::isa<mlir::StringAttr>(attr)) {
      flex_builder->String(name.c_str(),