9.3. Scoping hierarchy

Namespaces and scopes are organized in an hierarchy. Every namespace have a parent, except for the system namespace which is the namespace that contains all the build in functionality of Kick Assembler. Below this is the root namespace. As the name implies its the root namespace of the source code.

So the hierarchy is like this:

  1. System namespace & scope - Contains system mnemonics, constants, functions, macros and pseudocommands.

  2. Root namespace & scope - The root of the source code.

  3. User defined namespace & scopes - Created by namespace directives.

  4. User defined scopes - Created by macros, functions, for-loops, brackets {}, etc.

  5. More user defined scopes...

Lets look at an simple example. It contains some scopes and some nonsense code :


loop: //<-- 'loop' defined in the root scope

{     //<-- bracket scope 1 
   {  // <-- bracket scope 2
         ldx #0
   loop: stx $d020
         bne loop
         jmp start

The above code will form the scope hierarchy: System scope <- Root Scope <- BracketScope1 <- BracketScope2.

When Kick Assembler resolves a symbol, it checks if it is present in the the current scope. If it can't be found it looks in the parent scope. If it still can't be found it looks in the parent scope of the parent and so forth. In the above example, the 'jmp loop' is placed in BracketScope2, so 'loop' is resolved to the loop symbol in BracketScope2. But 'start' is not defined in BracketScope2 or BracketScope1 so it will be resolved to the label in the root scope.

Since no namespaces are defined in the above, the namespace hierarchy is: System namespace <- Root Namespace. The entities of namespaces is resolved similar to the scope resolving mechanism explained above.