简单计算器命令

命令行简单计算器和库

上下文无关文法

左递归

Goal -> Statement

Statement -> Expression

Expression -> Expression + Term | Expression - Term | Term ｜ + Term | - Term

Term -> Term * Factor | Term / Factor | Factor

Factor -> ( Expression ) | Factor ^ Factor| number

右递归

Goal -> Statement

Statement -> Expression

Expression -> Term Expression' | + Term Expression' | - Term Expression'

Expression' -> + Term Expression' | - Term Expression' | ε

Term -> Factor Term'

Term' -> * Factor Term' | / Factor Term' | ε

Factor -> ( Expression ) Factor' | number Factor'

Factor' -> ^ Factor | ε