functions

Documentation

Overview

This package contains signatures for functions used by collections and their methods.

Index

• type ComparerFunc
• type DeepCopyFunc
• type HashFunc
• type PredicateFunc

Types

type ComparerFunc

type ComparerFunc[T any] func(T, T) int

ComparerFunc is the signature for a function that compares two values.

This function allows the developer to supply a custom compare function to a collection for a type that is not one of the supported types. A compare function should return less than zero if a<b, zero if a==b or greater than zero if a>b and looks like this, e.g. for a collection typed on int

func myComparer(int a, int b) int {
	return a-b
}

type DeepCopyFunc

type DeepCopyFunc[T any] func(T) T

Function signature for a function to deep copy a collection element.

This function should return a new instance of type T copied from the original.

The default action when making copies of collection elements is to value-copy the element. If the element type is a pointer, or a struct containing pointers this may not be what you want. Should you need to deep-copy elements, supply an implementation of this function to the collection's constructor.

type HashFunc

type HashFunc[T any] func(T) uintptr

HashFunc is the signature for custom hash algorithms to use with HashSet.

The hash algorithms for the supported types are exported as function variables by the hashset package so can be used to construct hashes for struct types.

type PredicateFunc

type PredicateFunc[T any] func(T) bool

PredicateFunc is the signature for the function used in filtering and searching collections.

For many of the Enumerable methods, a predicate function must be given as an argument. A value is selected when the predicate function returns `true`. For instance, to filter all even numbers from a collection of int it might look like this

func filterEvens(int value) bool {
	return value % 2 == 0
}