go/src/internal/fmtsort/sort.go

type SortedMap …

type KeyValue …

// Sort accepts a map and returns a SortedMap that has the same keys and
// values but in a stable sorted order according to the keys, modulo issues
// raised by unorderable key values such as NaNs.
//
// The ordering rules are more general than with Go's < operator:
//
//   - when applicable, nil compares low
//   - ints, floats, and strings order by <
//   - NaN compares less than non-NaN floats
//   - bool compares false before true
//   - complex compares real, then imag
//   - pointers compare by machine address
//   - channel values compare by machine address
//   - structs compare each field in turn
//   - arrays compare each element in turn.
//     Otherwise identical arrays compare by length.
//   - interface values compare first by reflect.Type describing the concrete type
//     and then by concrete value as described in the previous rules.
func Sort(mapValue reflect.Value) SortedMap { … }

// compare compares two values of the same type. It returns -1, 0, 1
// according to whether a > b (1), a == b (0), or a < b (-1).
// If the types differ, it returns -1.
// See the comment on Sort for the comparison rules.
func compare(aVal, bVal reflect.Value) int { … }

// nilCompare checks whether either value is nil. If not, the boolean is false.
// If either value is nil, the boolean is true and the integer is the comparison
// value. The comparison is defined to be 0 if both are nil, otherwise the one
// nil value compares low. Both arguments must represent a chan, func,
// interface, map, pointer, or slice.
func nilCompare(aVal, bVal reflect.Value) (int, bool) { … }