Finish simple ast for num calculation including +-*/

Begin to Analyze 6*(3+4)
num:|6|:0:1
m_operator:|*|:1:2
(:|(|:2:3
num:|3|:3:4
m_operator:|+|:4:5
num:|4|:5:6
):|)|:6:7
(* (6 )(+ (3 )(4 )))