what can i do for defining scope of variable? (creating a new symbol table for each function and block or ...)

I'm use lex and yacc and i wrote a very basic interpreter. syntax is like as C

Keep a stack of scopes. Each time you enter a new scope, push a scope onto the stack. New variables are always added to the top scope.
This enables you to do as in C++ where a variable can be redeclared in a new scope and the highest-scoped version of that variable is what is used (and this typically only leads to bugs, but you can support it if you want).

When you leave a scope, pop the top scope off the stack and all the variables declared in it are gone. Simple.


L. Spiro