for _, file := range w.current.Files {
		ast.Inspect(file, func(n ast.Node) bool {
			switch n := n.(type) {
			case *ast.File:
				if isDeprecated(n.Doc) {
					mark(n.Name)
				}
				return true
			case *ast.GenDecl:
				if isDeprecated(n.Doc) {
					for _, spec := range n.Specs {
						switch spec := spec.(type) {
						case *ast.ValueSpec:
							for _, id := range spec.Names {
								mark(id)

)

var (
	errInvalidASTNode    = errors.New("invalid AST Node")
	errExpectedBool      = errors.New("expected bool")
	errLikeNonStrArg     = errors.New("LIKE clause requires string arguments")
	errLikeInvalidEscape = errors.New("LIKE clause has invalid ESCAPE character")
	errNotImplemented    = errors.New("not implemented")
)

// AST Node Evaluation functions
//

	n := len(values[0])
	r := values[0][1 : n-1]

	// Translate doubled quotes
	*qi = QuotedIdentifier(strings.ReplaceAll(r, `""`, `"`))
	return nil
}

// Types representing AST of SQL statement. Only SELECT is supported.

// Select is the top level AST node type
type Select struct {
	Expression *SelectExpression `parser:"\"SELECT\" @@"`
	From       *TableExpression  `parser:"\"FROM\" @@"`

	default:
		// TODO: traverse arguments and call aggregateRow on
		// them if they could be an ancestor of an
		// aggregation.
	}
	return nil
}

// getAggregate() implementation for each AST node follows. This is
// called after calling aggregateRow() on each input row, to calculate
// the final aggregate result.

func (e *FuncExpr) getAggregate() (*Value, error) {
	switch e.getFunctionName() {