Class Validation

validator/validator.h:73–113

A single validation to apply to an AST. May be empty if default constructed or moved from. use operator bool() to check if the validation is empty.

// May be empty if default constructed or moved from.
// use operator bool() to check if the validation is empty.
class Validation {
 public:
  // Tests the AST reports any issues to the context.
  //
  // Returns false if the AST is invalid.
  //
  // The same instance is used across Validate() so must be thread safe
  // (typically stateless).
  using ImplFunction =
      absl::AnyInvocable<bool(ValidationContext& context) const>;

  Validation() = default;
  explicit Validation(ImplFunction impl);
  Validation(ImplFunction impl, absl::string_view id);

  const ImplFunction& impl() const {
    ABSL_DCHECK(rep_ != nullptr);
    return rep_->impl;
  }

  absl::string_view id() const {
    ABSL_DCHECK(rep_ != nullptr);
    return rep_->id;
  }

  bool operator()(ValidationContext& context) const {
    ABSL_DCHECK(rep_ != nullptr);
    return rep_->impl(context);
  }

  explicit operator bool() const { return rep_ != nullptr; }

 private:
  struct Rep {
    ImplFunction impl;
    // Optional id if supported in environment config.
    std::string id;
  };

  std::shared_ptr<const Rep> rep_;
};

// A validator checks a set of semantic rules for a given AST.
class Validator {