go/src/sort/example_multi_test.go

type Change …

type lessFunc …

type multiSorter …

// Sort sorts the argument slice according to the less functions passed to OrderedBy.
func (ms *multiSorter) Sort(changes []Change) { … }

// OrderedBy returns a Sorter that sorts using the less functions, in order.
// Call its Sort method to sort the data.
func OrderedBy(less ...lessFunc) *multiSorter { … }

// Len is part of sort.Interface.
func (ms *multiSorter) Len() int { … }

// Swap is part of sort.Interface.
func (ms *multiSorter) Swap(i, j int) { … }

// Less is part of sort.Interface. It is implemented by looping along the
// less functions until it finds a comparison that discriminates between
// the two items (one is less than the other). Note that it can call the
// less functions twice per call. We could change the functions to return
// -1, 0, 1 and reduce the number of calls for greater efficiency: an
// exercise for the reader.
func (ms *multiSorter) Less(i, j int) bool { … }

var changes …

// ExampleMultiKeys demonstrates a technique for sorting a struct type using different
// sets of multiple fields in the comparison. We chain together "Less" functions, each of
// which compares a single field.
func Example_sortMultiKeys() { … }