A function can be given multiple definitions to handle special cases or differentiate between the types of the arguments.

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def factorial 0 = 1

def factorial n = n * factorial (n - 1)

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When a function is called each definition will be checked from top to bottom and if the argument matches the corresponding definition will get called.

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Pattern matching can be done on primitive type values, lists, tuples, structs and types in general. Just a variable (including _) will always match with any value.

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Using ... as the last element of an array, list or tuple signifies that it could contain more items.

For example match [int _, ...] [1, 2 ,3] is true.