Initial commit of modash

This was taken from github.com/lmika/gopkgs/fp

moslice/filter.go

@@ -0,0 +1,18 @@
+package moslice
+
+// Filter returns a slice containing all the elements of ts for which the passed in
+// predicate returns true.  If no items match the predicate, the function will return
+// an empty slice.  If ts is nil, the function will also return nil.
+func Filter[T any](ts []T, predicate func(t T) bool) []T {
+	if ts == nil {
+		return nil
+	}
+
+	filteredTs := make([]T, 0)
+	for _, t := range ts {
+		if predicate(t) {
+			filteredTs = append(filteredTs, t)
+		}
+	}
+	return filteredTs
+}