Reading dragon Book compiling Principles of Grammar Analysis (4) ...

The next step is to study the specific implementation of the syntax analysis ... There are always two kinds: top-down and bottom-up ... Let's take a look at top down.

So what exactly is the actual implementation of this:

Then you can find that the process of the algorithm implementation is in the most left derivation of the way to traverse all possible situations, while traversing the stack used, using the stack to do an explicit traversal instead of recursion ... It is important to note that (the next right hand side of T) if the order of the stack is N2 first into the stack, and you will find that the order in which it is checked is starting from the left side of the tokens array, you must Use the left derivation only) ...

So let's examine the algorithm itself:

Reading dragon Book compiling Principles of Grammar Analysis (4) ...