Commander

What's New:

User Changes:

• Added the (data pack) expression library!

This feature allows adding common expressions to a library where each is identified using an Identifier.

{
  "replace": false, // Can be omitted.
  "expressions": {
    "test:cool_expression": "score * 2.5",
    "test:boolean_expression": "level.isDay && !level.isRaining"
  }
}

Later on, these expressions can be evaluated inside other expressions using the library container, like so:

sqrt(library.my_id:some_value) * library.my_id:other_value

Or in execute/scoreboard brigadier commands using cmd:library. Prefer using the library in Brigadier commands! It does not require parsing the expression in-place!

• Brigadier macros in JSON commands should now correctly fail on dangling braces.

Dev Changes:

• Added more javadoc to the api package.
• Removed evalex and mapping-io from pom.xml
• Added LongExpression. Similar to Arithmetica and BooleanExpression, but for longs!
• Tried to fix expression equality.
• Added missing 'parameter' methods to Arithmetica, BooleanExpression and BrigadierMacro.
• Added Expression.Result#NULL.

Other Changes:

• The mod should now fail with slightly better error messages.
• Inlined constant BooleanExpression instances.

What's New:

User Changes:

• Added the (data pack) expression library!

This feature allows adding common expressions to a library where each is identified using an Identifier.

{
  "replace": false, // Can be omitted.
  "expressions": {
    "test:cool_expression": "score * 2.5",
    "test:boolean_expression": "level.isDay && !level.isRaining"
  }
}

Later on, these expressions can be evaluated inside other expressions using the library container, like so:

sqrt(library.my_id:some_value) * library.my_id:other_value

Or in execute/scoreboard brigadier commands using cmd:library. Prefer using the library in Brigadier commands! It does not require parsing the expression in-place!

• Brigadier macros in JSON commands should now correctly fail on dangling braces.

Dev Changes:

• Added more javadoc to the api package.
• Removed evalex and mapping-io from pom.xml
• Added LongExpression. Similar to Arithmetica and BooleanExpression, but for longs!
• Tried to fix expression equality.
• Added missing 'parameter' methods to Arithmetica, BooleanExpression and BrigadierMacro.
• Added Expression.Result#NULL.

Other Changes:

• The mod should now fail with slightly better error messages.
• Inlined constant BooleanExpression instances.

What's New:

User Changes:

• Added ?. and ? null safe operators.
  • ?. Used on structures. Same as ., but returns null if there's no such field in structure.
  • ? Used with anything that can be null. Returns the right operand if left is null or left if not.

These operators allow you to quickly check for nulls in your expressions. Let's image a situation like this:

You have a variable struct.x which might not exist and maybe null. Before, you'd have to write something like this:

if(structContainsKey(struct, 'x') && struct.x != null, struct.x, valueElse())'

Now this can be shortened to: struct?.x ? valueElse(). Do note that ? has a very low precedence, so in ambiguous cases you'll have to wrap it in parentheses. e.g. 23 + struct?.x ? 23 -> 23 + (struct?.x ? 23).

• Java Optionals are now unwrapped in expressions.
• Minecraft Identifiers are now converted to strings in expressions.
• Gson elements can now be used in expressions.

Dev Changes:

• Fixed equals on CustomDataAccessors.
• Added LootContext as an argument for the CustomFields#addVirtualField function.

Other Changes:

• Updated mEvalEx to fix expression inlining.

What's New:

User Changes:

• Added ?. and ? null safe operators.
  • ?. Used on structures. Same as ., but returns null if there's no such field in structure.
  • ? Used with anything that can be null. Returns the right operand if left is null or left if not.

These operators allow you to quickly check for nulls in your expressions. Let's image a situation like this:

You have a variable struct.x which might not exist and maybe null. Before, you'd have to write something like this:

if(structContainsKey(struct, 'x') && struct.x != null, struct.x, valueElse())'

Now this can be shortened to: struct?.x ? valueElse(). Do note that ? has a very low precedence, so in ambiguous cases you'll have to wrap it in parentheses. e.g. 23 + struct?.x ? 23 -> 23 + (struct?.x ? 23).

• Java Optionals are now unwrapped in expressions.
• Minecraft Identifiers are now converted to strings in expressions.
• Gson elements can now be used in expressions.

Dev Changes:

• Fixed equals on CustomDataAccessors.
• Added LootContext as an argument for the CustomFields#addVirtualField function.

Other Changes:

• Updated mEvalEx to fix expression inlining.

What's New:

User Changes:

• Added ?. and ? null safe operators.
  • ?. Used on structures. Same as ., but returns null if there's no such field in structure.
  • ? Used with anything that can be null. Returns the right operand if left is null or left if not.

These operators allow you to quickly check for nulls in your expressions. Let's image a situation like this:

You have a variable struct.x which might not exist and maybe null. Before, you'd have to write something like this:

if(structContainsKey(struct, 'x') && struct.x != null, struct.x, valueElse())'

Now this can be shortened to: struct?.x ? valueElse(). Do note that ? has a very low precedence, so in ambiguous cases you'll have to wrap it in parentheses. e.g. 23 + struct?.x ? 23 -> 23 + (struct?.x ? 23).

• Java Optionals are now unwrapped in expressions.
• Minecraft Identifiers are now converted to strings in expressions.
• Gson elements can now be used in expressions.

Dev Changes:

• Fixed equals on CustomDataAccessors.
• Added LootContext as an argument for the CustomFields#addVirtualField function.

Other Changes:

• Updated mEvalEx to fix expression inlining.

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.

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.

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.