printer.RawFormat
const RawFormat = iota
printer.SourcePos
const SourcePos = iota
printer.TabIndent
const TabIndent = iota
printer.UseSpaces
const UseSpaces = iota
printer.Fprint
// Fprint "pretty-prints" an AST node to output.
// It calls Config.Fprint with default settings.
// Note that gofmt uses tabs for indentation but spaces for alignment;
// use format.Node (package go/format) for output that matches gofmt.
func Fprint(output io.Writer, fset *token.FileSet, node any) error