How to create a symbol table?

Question

Can I use malloc to add symbol table entries? How do I traverse the table to check if something is already there?

Answer 1

In general, symbol tables are implemented through hash tables. Hash tables have the advantage of O(1) store and retrieve, but they don't store data sequentially.

Assuming you're working in C you can uses malloc(), but it requires more work than that. The provided link should enlighten you.

Answer 2

A "symbol table" doesn't describe a particular kind of data structure. It merely describes the primary modes of operation: adding symbols and retrieving symbols by name. Symbols here are basically attributed names. For a compiler class, one such an attribute could be IsAFunction.

C has very few built-in datastructures. You'd have to create one yourself in this case. In C++, it would just be a matter of a std::map<std::string, Attributes>. Now presumably if you're in a compiler class, you should already know how to implement datastructures in C (including the use of malloc()). If not, then a compiler class really isn't for you.

Answer 3

I'v done that with a double chained linked list before. But now i will definitively do it with a hashtable. It's just a datastructure.