[英]Extending Grammar for LR Parser
I have the following grammar for basic arithmetic expressions 对于基本的算术表达式,我有以下语法
E -> E + T
E -> T
T -> T * F
T -> F
F -> (E)
F -> id
Where E is expression, T is term, F is factor. 其中E是表达式,T是项,F是因子。 I'm wondering how I can extend this grammar to support further arithmetic operations such exponents possibly represented with ^ or logarithm.
我想知道如何扩展此语法以支持进一步的算术运算,例如可能用^或对数表示的指数。
Thanks 谢谢
Since exponentation has higher precedence you could use the following grammar: 由于指数优先级较高,因此可以使用以下语法:
E -> E + T
E -> T
T -> T * F
T -> F
F -> G ^ F
F -> G
G -> log(E)
G -> (E)
G -> id
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