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#ifndef SRC_TINT_LANG_WGSL_SEM_MEMBER_ACCESSOR_EXPRESSION_H_
#define SRC_TINT_LANG_WGSL_SEM_MEMBER_ACCESSOR_EXPRESSION_H_

#include "src/tint/lang/wgsl/sem/accessor_expression.h"
#include "src/tint/utils/containers/vector.h"

// Forward declarations
namespace tint::ast {
class MemberAccessorExpression;
}  // namespace tint::ast
namespace tint::core::type {
class StructMember;
}  // namespace tint::core::type

namespace tint::sem {

/// StructMemberAccess holds the semantic information for a
/// ast::MemberAccessorExpression node that represents an access to a structure
/// member.
class StructMemberAccess final : public Castable<StructMemberAccess, AccessorExpression> {
  public:
    /// Constructor
    /// @param declaration the AST node
    /// @param type the resolved type of the expression
    /// @param statement the statement that owns this expression
    /// @param constant the constant value of the expression. May be null
    /// @param object the object that holds the member being accessed
    /// @param member the structure member
    /// @param root_ident the (optional) root identifier for this expression
    StructMemberAccess(const ast::MemberAccessorExpression* declaration,
                       const core::type::Type* type,
                       const Statement* statement,
                       const core::constant::Value* constant,
                       const ValueExpression* object,
                       const core::type::StructMember* member,
                       const Variable* root_ident = nullptr);

    /// Destructor
    ~StructMemberAccess() override;

    /// @returns the structure member
    core::type::StructMember const* Member() const { return member_; }

  private:
    core::type::StructMember const* const member_;
};

/// Swizzle holds the semantic information for a ast::MemberAccessorExpression
/// node that represents a vector swizzle.
class Swizzle final : public Castable<Swizzle, AccessorExpression> {
  public:
    /// Constructor
    /// @param declaration the AST node
    /// @param type the resolved type of the expression
    /// @param statement the statement that owns this expression
    /// @param constant the constant value of the expression. May be null
    /// @param object the object that holds the member being accessed
    /// @param indices the swizzle indices
    /// @param root_ident the (optional) root identifier for this expression
    Swizzle(const ast::MemberAccessorExpression* declaration,
            const core::type::Type* type,
            const Statement* statement,
            const core::constant::Value* constant,
            const ValueExpression* object,
            VectorRef<uint32_t> indices,
            const Variable* root_ident = nullptr);

    /// Destructor
    ~Swizzle() override;

    /// @return the swizzle indices, if this is a vector swizzle
    const auto& Indices() const { return indices_; }

  private:
    tint::Vector<uint32_t, 4> const indices_;
};

/// Holds the base vector and collapsed indices of a potentially chained swizzle.
struct CollapsedSwizzle {
    /// The base vector expression
    const ValueExpression* vector = nullptr;
    /// The collapsed swizzle indices
    tint::Vector<uint32_t, 4> indices;
};

/// Collapse a possibly nested chain of swizzles on the lhs of an assignment into a single set of
/// swizzle indices on the base vector.
///
/// Note that target components cannot be repeated in lhs swizzles used for assignment,
/// so each consecutive swizzle on a vector will produce a smaller or equal sized vector (i.e.
/// v.xyzw.xy.yx.x).
///
/// @param swizzle the outermost swizzle node
/// @returns the collapsed swizzle
CollapsedSwizzle CollapseLhsSwizzle(const Swizzle* swizzle);

}  // namespace tint::sem

#endif  // SRC_TINT_LANG_WGSL_SEM_MEMBER_ACCESSOR_EXPRESSION_H_
