Commander

What's New:

User Changes:

• Added arrayFindAny and arrayFindFirst functions to expressions. As the name suggests, those functions will try to find an element of an array or return null if the array is empty.
• Added chain function to expressions. This function operates on the results of the first one and allows chaining multiple function calls together like so:

  //`it` is the result of the previous function, unless there's a lower level lamda.
  chain(arrayOf(2, 3, 6), arrayMap(it, sqrt(it)), arrayFindFirst(it));
  //this is the same as:
  arrayFindFirst(arrayMap(arrayOf(2, 3, 6), sqrt(it)))
  

• Added remove to cmd:data.
• Added cmd:operate to the scoreboard players command.
• Added registry access for expressions! Now you can access the game's static and dynamic content registries by using new Registry and DynamicRegistry functions.
  • Why is this useful? For example, this allows you to compare item stacks based on their item type:

  this_entity.getHandSlots[0].getItem == Registry('item').access.chest
  

  • For item and block registries there is a shortcut: Item, Block.

  this_entity.getHandSlots[0].getItem == Item('chest')
  

  • Biome and DimensionType are available dynamic registry shortcuts.

Dev Changes:

There's a handful new experimental APIs, which allow you to extend the expression system.

• Exposed Object getValue() and Result convert(Object o) in Expression.Result.
• Exposed Expression eval(LootContext context, Map<String, Object> parameters) in Expression.
• Exposed ProxyMap, ObjectConverter and CustomDataAccessor (which is now a valid data type).
• Exposed CustomFields. One of the more interesting APIs. Allows adding new 'virtual' fields to reflective expression objects.

  static {
    CustomFields.addVirtualField(Entity.class, "nbt", NbtPredicate::entityToNbt);
  }
  

Other Changes:

• Switched to a custom fork of EvalEx.
• Switched to 16-digit precision from the EvalEx's standard of 68-digit.