This switch statement is working with one Case how to make it multiple case Bison

问题

This switch statement is working with one Case how to make it multiple case

S: Statement {printf("ACCEPTED");}

Statement:SWITCH BRO ID BRC CBO E CBC

E: A 
 | A C




A: A B 
 | CASE DIGIT D 


B:  BREAK SEMI


C : DEFAULT D B



D : COLON ID SEMI

 ;

This is an issue i want to make grammar accepted with multiple cases

回答1:

Your grammar is terrible, and does not account for repetition of the CASE. You need to discover how to express lists of things. The general pattern is like:

item: ....
items: item
       | item ';' items

So we have:

case: CASE DIGIT ':' stmts
default: DEFAULT ':' stmts
cases: case | default | case ';' cases

You should also find out how you can trace the parser for debugging. With yacc, you can set the environment variable YYDEBUG and it will print a quite verbose of all parser states.

回答2:

Correct switch grammar Don't need to use semicolon in between A E space will work.

Statement:SWITCH BRO ID BRC CBO E CBC

E: A | A C | A E

A: A B | CASE DIGIT D

B: BREAK SEMI

C : DEFAULT D B

D : COLON ID SEMI

来源：https://stackoverflow.com/questions/21073980/this-switch-statement-is-working-with-one-case-how-to-make-it-multiple-case-biso