Stack¶
Squirrel exchanges values with the virtual machine through a stack. This mechanism has been inherited from the language Lua. For instance to call a Squirrel function from native code it is necessary to push the function and the arguments in the stack and then invoke the function; also when Squirrel calls a native function the parameters will be in the stack as well.
Stack Indexes¶
Many API functions can arbitrarily refer to any element in the stack through an index. The stack indexes follow these conventions:
- 1 is the stack base
- Negative indexes are considered an offset from top of the stack. For instance -1 is always the last item pushed to the stack
- 0 is an invalid index
See this example stack for reference:
| Stack | Positive index | Negative index |
|---|---|---|
| p4 | 4 | -1 |
| p3 | 3 | -2 |
| p2 | 2 | -3 |
| p1 | 1 | -4 |
Stack manipulation¶
The Squirrel API offers several functions to push and retrieve data from the Stack.
__int64 removeFromStack(HSquirrelVM* sqvm)
Note
This function (`server.dll+0x7000```) is not available in the launcher or plugins at the moment.
You can open a PR if you need it now.
HSquirrelVM* sqvmthe target vm
pops the top item of the stack.