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Package fmtsort

import "internal/fmtsort"

Overview ▾

Package fmtsort provides a general stable ordering mechanism for maps, on behalf of the fmt and text/template packages. It is not guaranteed to be efficient and works only for types that are valid map keys.

type SortedMap

SortedMap represents a map's keys and values. The keys and values are aligned in index order: Value[i] is the value in the map corresponding to Key[i].

type SortedMap struct {
    Key   []reflect.Value
    Value []reflect.Value

func Sort

func Sort(mapValue reflect.Value) *SortedMap

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 (*SortedMap) Len

func (o *SortedMap) Len() int

func (*SortedMap) Less

func (o *SortedMap) Less(i, j int) bool

func (*SortedMap) Swap

func (o *SortedMap) Swap(i, j int)