[antlr-interest] Nested Matching Parenthesis

[cgodfrey86]

Hello,

I'm trying to write a parser grammar that will check for matching 
parenthesis. There can be any number of parenthesis, but they must 
match

So, 
(test) or 
((test)) or 
(((test))) are all valid expressions

(test or 
((test 
etc are all invalid

So, I have a rule like this

expr : PATTERN
      | OPEN_PAREN PATTERN CLOSE_PAREN
      ;

Would it make sense to write rules which count the number of 
consecutive open parens and close parens and check for matches? or is 
there an easier way to approach this that I am missing?

start_parens : (OPEN_PAREN)+;
end_parens : (CLOSE_PARENS)+;

Thanks In Advance


 

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