The exponential operator in Matlab grammar using ANTLR4 does not work correctly-CodePudding

I have been using matlab grammar from

Problem might be in the multiplicative expression, but I do not have best solution for the issue in my mind. To be honest I do not have any solution for this. Can anybody please tell me how to fix this?

multiplicative_expression
   : unary_expression
   | multiplicative_expression '*' unary_expression
   | multiplicative_expression '/' unary_expression
   | multiplicative_expression '\\' unary_expression
   | multiplicative_expression '^' unary_expression
   | multiplicative_expression ARRAYMUL unary_expression
   | multiplicative_expression ARRAYDIV unary_expression
   | multiplicative_expression ARRAYRDIV unary_expression
   | multiplicative_expression ARRAYPOW unary_expression
   ;

CodePudding user response：

I think you need to replace the section multiplicative_expression with the following:

multiplicative_expression
   : pow_expression
   | multiplicative_expression '*' pow_expression
   | multiplicative_expression '/' pow_expression
   | multiplicative_expression '\\' pow_expression
   | multiplicative_expression ARRAYMUL pow_expression
   | multiplicative_expression ARRAYDIV pow_expression
   | multiplicative_expression ARRAYRDIV pow_expression
   ;

and then include an additional section pow_expression:

pow_expression
   : unary_expression
   | pow_expression '^' unary_expression
   | pow_expression ARRAYPOW unary_expression
   ;

That should give the exponentiation operators a higher precedence than the multiplicative operators.

However, if you're trying to actually implement MATLAB's actual grammar, you should realize that this grammar on GitHub is not a very good reflection of it. MATLAB has further exponentiation operators (.^-, .^ , .^~, ^-, ^ , ^~) for example, and there are entire categories of syntax, e.g. all the object-oriented functionality, that are not covered at all.