Creating a language interpreter

Question

I am trying to understand how a language interpreter works. Can you guys point me the general lines on how an interpreter works?

I mean, suppose I have some lines written like this

10  x = 200;
20  for r = x to 1000 step 1
25  z = r + 32;
30  print z;
40  next r;
50  end;

what's the best way to build an interpreter that could run something like that?

Having a large matrix containing all functions allowed and searching for a match? The first line, for example: it is assigning 200 to a variable x, but these are symbols that does not exist.

If you guys can give me the direction...

Thanks for any help.

Answer 1

Compiler creation is a complex topic (an interpreter can be seen as a special compiler).

You have to first parse it - try to understand the syntax and then create some internal representation (abstract syntax tree) and then create some execution logic.

Wikpedia suggests http://mcs.une.edu.au/~comp319/