type CheckedAST struct {
	Expr         *exprpb.Expr
	SourceInfo   *exprpb.SourceInfo
	TypeMap      map[int64]*types.Type
	ReferenceMap map[int64]*ReferenceInfo
}

type ExprKind int

const (
	// UnspecifiedKind represents an unset expression with no specified properties.
	UnspecifiedKind ExprKind = iota

	// LiteralKind represents a primitive scalar literal.
	LiteralKind

	// IdentKind represents a simple variable, constant, or type identifier.
	IdentKind

	// SelectKind represents a field selection expression.
	SelectKind

	// CallKind represents a function call.
	CallKind

	// ListKind represents a list literal expression.
	ListKind

	// MapKind represents a map literal expression.
	MapKind

	// StructKind represents a struct literal expression.
	StructKind

	// ComprehensionKind represents a comprehension expression generated by a macro.
	ComprehensionKind
)

type ExprMatcher func(NavigableExpr) bool

type NavigableCallExpr interface {
	// FunctionName returns the name of the function.
	FunctionName() string

	// Target returns the target of the expression if one is present.
	Target() NavigableExpr

	// Args returns the list of call arguments, excluding the target.
	Args() []NavigableExpr

	// ReturnType returns the result type of the call.
	ReturnType() *types.Type
	// contains filtered or unexported methods
}

type NavigableComprehensionExpr interface {
	// IterRange returns the iteration range expression.
	IterRange() NavigableExpr

	// IterVar returns the iteration variable name.
	IterVar() string

	// AccuVar returns the accumulation variable name.
	AccuVar() string

	// AccuInit returns the accumulation variable initialization expression.
	AccuInit() NavigableExpr

	// LoopCondition returns the loop condition expression.
	LoopCondition() NavigableExpr

	// LoopStep returns the loop step expression.
	LoopStep() NavigableExpr

	// Result returns the comprehension result expression.
	Result() NavigableExpr
	// contains filtered or unexported methods
}

type NavigableEntry interface {
	// Key returns the map entry key expression.
	Key() NavigableExpr

	// Value returns the map entry value expression.
	Value() NavigableExpr

	// IsOptional returns whether the entry is optional.
	IsOptional() bool
	// contains filtered or unexported methods
}

type NavigableExpr interface {
	// ID of the expression as it appears in the AST
	ID() int64

	// Kind of the expression node. See ExprKind for the valid enum values.
	Kind() ExprKind

	// Type of the expression node.
	Type() *types.Type

	// Parent returns the parent expression node, if one exists.
	Parent() (NavigableExpr, bool)

	// Children returns a list of child expression nodes.
	Children() []NavigableExpr

	// ToExpr adapts this NavigableExpr to a protobuf representation.
	ToExpr() *exprpb.Expr

	// AsCall adapts the expr into a NavigableCallExpr
	//
	// The Kind() must be equal to a CallKind for the conversion to be well-defined.
	AsCall() NavigableCallExpr

	// AsComprehension adapts the expr into a NavigableComprehensionExpr.
	//
	// The Kind() must be equal to a ComprehensionKind for the conversion to be well-defined.
	AsComprehension() NavigableComprehensionExpr

	// AsIdent adapts the expr into an identifier string.
	//
	// The Kind() must be equal to an IdentKind for the conversion to be well-defined.
	AsIdent() string

	// AsLiteral adapts the expr into a constant ref.Val.
	//
	// The Kind() must be equal to a LiteralKind for the conversion to be well-defined.
	AsLiteral() ref.Val

	// AsList adapts the expr into a NavigableListExpr.
	//
	// The Kind() must be equal to a ListKind for the conversion to be well-defined.
	AsList() NavigableListExpr

	// AsMap adapts the expr into a NavigableMapExpr.
	//
	// The Kind() must be equal to a MapKind for the conversion to be well-defined.
	AsMap() NavigableMapExpr

	// AsSelect adapts the expr into a NavigableSelectExpr.
	//
	// The Kind() must be equal to a SelectKind for the conversion to be well-defined.
	AsSelect() NavigableSelectExpr

	// AsStruct adapts the expr into a NavigableStructExpr.
	//
	// The Kind() must be equal to a StructKind for the conversion to be well-defined.
	AsStruct() NavigableStructExpr
	// contains filtered or unexported methods
}

type NavigableField interface {
	// FieldName returns the name of the field.
	FieldName() string

	// Value returns the field initialization expression.
	Value() NavigableExpr

	// IsOptional returns whether the field is optional.
	IsOptional() bool
	// contains filtered or unexported methods
}

type NavigableListExpr interface {
	// Elements returns the list elements as navigable expressions.
	Elements() []NavigableExpr

	// OptionalIndicies returns the list of optional indices in the list literal.
	OptionalIndices() []int32

	// Size returns the number of elements in the list.
	Size() int
	// contains filtered or unexported methods
}

type NavigableMapExpr interface {
	// Entries returns the map key value pairs as NavigableEntry values.
	Entries() []NavigableEntry

	// Size returns the number of entries in the map.
	Size() int
	// contains filtered or unexported methods
}

type NavigableSelectExpr interface {
	// Operand returns the selection operand expression.
	Operand() NavigableExpr

	// FieldName returns the field name being selected from the operand.
	FieldName() string

	// IsTestOnly indicates whether the select expression is a presence test generated by a macro.
	IsTestOnly() bool
	// contains filtered or unexported methods
}

type NavigableStructExpr interface {
	// TypeName returns the struct type name.
	TypeName() string

	// Fields returns the set of field initializers in the struct expression as NavigableField values.
	Fields() []NavigableField
	// contains filtered or unexported methods
}

type ReferenceInfo struct {
	Name        string
	OverloadIDs []string
	Value       ref.Val
}