Write a grammar (not necessarily LL(1)) that recognizes various forms of variabl

Question

Write a grammar (not necessarily LL(1)) that recognizes various forms of variables in C++, which should include the simple variable (e.g. a, b, c), array variables (e.g. a[10], a[10][10], a[10][10][10])), class members (e.g. a. data, a.data.name, ...), pointer variables (e.g. a rightarrow data, a rightarrow data>name), and composite variables that are combinations of the above forms (e.g. a rightarrow bb[100][200][300].data rightarrow mdata.bb[100]). You can assume the array index can only be a number.

Explanation / Answer

note:s is the start symbol, * indicates zero or more occureances, + indicates one or more occurances

s -->alpha|| index ||alpha.alpha ||pointer ||comb                 

alpha -->any alphabet from A-Z or a-z ||alpha+_alpha* ||alpha+num*alpha*    ||alpha* s* ||alpha*

index-->alpha[num+] ||alpha[num+][num+] ||alpha[num+][num+][num+] || index* s*

num -->any number from 0-9

pointer --> alpha->alpha.alpha || alpha->index || alpha->alpha ||pointer* s*

Eg: variable is a->bb[100][200][300].data->mdata.bb[100]

s-->alpha.alpha

s-->alpha->alpha*s*

s-->alpha->s

s-->alpha->alpha.alpha     //let this be @

s-->alpha->alpha.s        

s-->alpha->alpha.index

s-->s->alpha.index

s-->alpha->alpha.alpha->alpha.index   //from @

s-->a->alpha[num+][num]+[num+].alpha->alpha.alpha[num+]

s-->a->alpha*[100][200][300].alpha*->alpha*.alpha*[100]

s-->a->bb[100][200][300].data->mdata.bb[100]

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