// Copyright 2022 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
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//
//     http://www.apache.org/licenses/LICENSE-2.0
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#ifndef SRC_TINT_LANG_WGSL_AST_TRANSFORM_PROMOTE_INITIALIZERS_TO_LET_H_
#define SRC_TINT_LANG_WGSL_AST_TRANSFORM_PROMOTE_INITIALIZERS_TO_LET_H_

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

namespace tint::ast::transform {

/// A transform that hoists array and structure initializers, and identifiers resolving to a
/// 'const' array to a 'let' variable, declared just before the statement of usage.
/// This transform is used by backends that do not support expressions that operate on an immediate
/// array or structure. For example, the following is not immediately expressable for HLSL:
///   `array<i32, 2>(1, 2)[0]`
/// @see crbug.com/tint/406
class PromoteInitializersToLet final : public Castable<PromoteInitializersToLet, Transform> {
  public:
    /// Constructor
    PromoteInitializersToLet();

    /// Destructor
    ~PromoteInitializersToLet() override;

    /// @copydoc Transform::Apply
    ApplyResult Apply(const Program* program,
                      const DataMap& inputs,
                      DataMap& outputs) const override;
};

}  // namespace tint::ast::transform

#endif  // SRC_TINT_LANG_WGSL_AST_TRANSFORM_PROMOTE_INITIALIZERS_TO_LET_H_