```
public class ControlTree
extends Object
```
The purpose of this class is to provide a control structure to, in-line, label branches in a list of instructions. Wasm has a structured form of control flow. There is no `jmp` to an address. So instead each branching point can only "jump" to a few points internal to the function we are executing in. This algorithm mimics the control flow rules and annotates each branching instruction with the labels (here the jumping point is the index of the instruction in the body) that it can jump to. Branching instructions can only jump to the beginning of a block if this target is a loop, or the end of a block for every other target block. It's up to the Machine to decide, based on what is on the stack, which label to choose. Here is an example on how to label some code. The left side contains indexes, comments show where the labels go 0 (local i32) 1 (block 2 (block 3 (block ;; x == 0 4 local.get 0 5 i32.eqz 6 br_if 0 ;; true=14 false=7 ;; x == 1 7 local.get 0 8 i32.const 1 9 i32.eq 10 br_if 1 ;; true=17 false=11 ;; the `else` case 11 i32.const 7 12 local.set 1 13 br 2 ;; true=19 ) 14 i32.const 42 15 local.set 1 16 br 1 ;; true=19 ) 17 i32.const 99 18 local.set 1 ) 19 local.get 1) This is very sub-optimal at the moment

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addCallback(Consumer<Integer> callback)`
`void`	`addNested(ControlTree nested)`
`Instruction`	`instruction()`
`int`	`instructionNumber()`
`boolean`	`isRoot()`
`List<ControlTree>`	`nested()`
`ControlTree`	`parent()`
`void`	`setFinalInstructionNumber(int finalInstructionNumber, Instruction end)`
`ControlTree`	`spawn(int initialInstructionNumber, Instruction instruction)`

public ControlTree spawn(int initialInstructionNumber,
                         Instruction instruction)

public void addNested(ControlTree nested)

public void addCallback(Consumer<Integer> callback)

public void setFinalInstructionNumber(int finalInstructionNumber,
                                      Instruction end)

Class ControlTree