subtype

A type that supports all the operations of its supertype. The subtype keyword can be used with parentheses to specify that a type is constrained to a certain type.

A type that supports all the operations of its supertype. The subtype keyword can be used with parentheses to specify that a type is constrained to a certain type. For example, several Verse array methods use subtype to define that all elements of the array must have the supertype comparable for the method to work.

Verse 
(Input:[]t where t:subtype(comparable)).RemoveFirstElement<public>
(ElementToRemove:t)<computes><decides>:[]t
RemoveFirstElement

This needs the array elements to have a supertype of comparable so that it can determine if any of the elements in the array are equal to the ElementToRemove argument.

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