// Copyright 2022 The Dawn & Tint Authors
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef SRC_TINT_LANG_WGSL_AST_CONST_H_
#define SRC_TINT_LANG_WGSL_AST_CONST_H_

#include "src/tint/lang/wgsl/ast/variable.h"

namespace tint::ast {

/// A "const" declaration is a name for a module-scoped or function-scoped creation-time value.
/// const must have a initializer expression.
///
/// Examples:
///
/// ```
///   const n  = 123;                           // Abstract-integer typed constant
///   const pi = 3.14159265359;                 // Abstract-float typed constant
///   const max_f32 : f32 = 0x1.fffffep+127;    // f32 typed constant
/// ```
/// @see https://www.w3.org/TR/WGSL/#creation-time-consts
class Const final : public Castable<Const, Variable> {
  public:
    /// Create a 'const' creation-time value variable.
    /// @param source the variable source
    /// @param name the variable name
    /// @param type the declared variable type
    /// @param initializer the initializer expression. Must not be nullptr.
    /// @param attributes the variable attributes
    Const(NodeID nid,
          const Source& source,
          const Identifier* name,
          Type type,
          const Expression* initializer,
          VectorRef<const Attribute*> attributes);

    /// Destructor
    ~Const() override;

    /// @returns "const"
    const char* Kind() const override;
};

}  // namespace tint::ast

#endif  // SRC_TINT_LANG_WGSL_AST_CONST_H_
