Dollar Functions¶

Nbt Crafting v3 introduces functions inside of dollar expressions. This site will describe the most important functions and the use of anonymous functions (lambdas).

Built-in functions¶

General¶

Function	Description
ifNull(a, b)	Checks whether a is null and returns b if it is, otherwise returns a.
ifEmpty	Checks whether a is empty (null or empty list/compound) and returns b if it is, otherwise returns a.

Stacks/Items¶

Function	Description
count(a)	Returns the stack count of the given stack a.
id(a)	Returns the item id of the given stack a.
maxCount(a)	Returns the max stack count of the given stack a.
maxDamage(a)	Returns the max damage of the given stack a.

Containers/Lists¶

Function	Description
size(a)	Returns the size of the container a.
map(a, l)	Maps the container a to a new container using the lambda function l.
distinct(a, l, [b])	Removes duplicate elements of the container a, uses lambda l to get the unique element. b sets whether the first or the last duplicate element will be kept.
filter(a, l)	Removes elements of the container a, by evaluating the lambda l (true will be kept)
combine(a, b, ...)	Combines an arbitrary number of either lists or compounds.
any(a, l)	Checks if the lambda l returns true for any of the elements in a
all(a, l)	Checks if the lambda l returns true for all of the elements in a

Math¶

Function	Description
mod(a, b)	Returns the non-negative modulus of a and b
abs(a)	Returns the absolute value of a
power(a, b)	Returns the power of a to b
min(a, ...)	Returns the minimum number. Parameters may be numeric or lists of numbers
max(a, ...)	Returns the maximum number. Parameters may be numeric or lists of numbers

Lambdas¶

Dollar expressions also support lambdas. Lambda expressions may be written as:

() -> expr:

Takes no arguments and returns the value of epxr.

a -> expr:

Takes a single argument and returns the value of epxr.

(a,[b, ...]) -> expr:

Takes a certain number of arguments and returns the value of epxr.

While multi-statement lambda expressions are supported, their syntax has not been stabilized yet.