30 lines
942 B
Go
30 lines
942 B
Go
package gomap
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// The Predicate is a type alias for a function that
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// takes in a parameter and returns a boolean.
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// The predicate is similar to Java's `Predicate<T>`,
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// without the generic usage. This makes the usage of a predicate not
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// necessarily type safe. This also means that the writer of the predicate
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// has to write code that they trust when passing the predicate into the filter.
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type Predicate func(interface{}) bool
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func (l *MappableList) Filter(predicate Predicate) MappableList {
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// Get the iterator.
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itr := l.Iterator()
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// Utilise the iterator recursively, to map
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// the entire list.
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var newArray List
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// We utilize the goto call to avoid recursively calling the filter function.
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sorter:
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if next, value := itr.Next(); next {
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// Filter by the predicate.
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if predicate(value) {
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newArray.Add(value)
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}
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// Jump back to the sorter label.
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goto sorter
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}
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// Return the list.
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return MappableList{&newArray}
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}
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