ast.go
func (ps *printState) writeByte(b byte) {
	ps.last = b
	ps.buf.WriteByte(b)
}
func (ps *printState) writeByte(b byte) {
	ps.last = b
	ps.buf.WriteByte(b)
}
func ( ps * printState ) writeByte ( b byte ) { ps . last = b ps . buf . WriteByte ( b ) }
// writeByte adds a byte to the string being printed.
writeByte adds a byte to the string being printed .