--- /dev/null
+// Copyright 2017, The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE.md file.
+
+package cmpopts
+
+import (
+ "fmt"
+ "reflect"
+ "sort"
+
+ "github.com/google/go-cmp/cmp"
+ "github.com/google/go-cmp/cmp/internal/function"
+)
+
+// SortSlices returns a Transformer option that sorts all []V.
+// The less function must be of the form "func(T, T) bool" which is used to
+// sort any slice with element type V that is assignable to T.
+//
+// The less function must be:
+// • Deterministic: less(x, y) == less(x, y)
+// • Irreflexive: !less(x, x)
+// • Transitive: if !less(x, y) and !less(y, z), then !less(x, z)
+//
+// The less function does not have to be "total". That is, if !less(x, y) and
+// !less(y, x) for two elements x and y, their relative order is maintained.
+//
+// SortSlices can be used in conjunction with EquateEmpty.
+func SortSlices(lessFunc interface{}) cmp.Option {
+ vf := reflect.ValueOf(lessFunc)
+ if !function.IsType(vf.Type(), function.Less) || vf.IsNil() {
+ panic(fmt.Sprintf("invalid less function: %T", lessFunc))
+ }
+ ss := sliceSorter{vf.Type().In(0), vf}
+ return cmp.FilterValues(ss.filter, cmp.Transformer("cmpopts.SortSlices", ss.sort))
+}
+
+type sliceSorter struct {
+ in reflect.Type // T
+ fnc reflect.Value // func(T, T) bool
+}
+
+func (ss sliceSorter) filter(x, y interface{}) bool {
+ vx, vy := reflect.ValueOf(x), reflect.ValueOf(y)
+ if !(x != nil && y != nil && vx.Type() == vy.Type()) ||
+ !(vx.Kind() == reflect.Slice && vx.Type().Elem().AssignableTo(ss.in)) ||
+ (vx.Len() <= 1 && vy.Len() <= 1) {
+ return false
+ }
+ // Check whether the slices are already sorted to avoid an infinite
+ // recursion cycle applying the same transform to itself.
+ ok1 := sort.SliceIsSorted(x, func(i, j int) bool { return ss.less(vx, i, j) })
+ ok2 := sort.SliceIsSorted(y, func(i, j int) bool { return ss.less(vy, i, j) })
+ return !ok1 || !ok2
+}
+func (ss sliceSorter) sort(x interface{}) interface{} {
+ src := reflect.ValueOf(x)
+ dst := reflect.MakeSlice(src.Type(), src.Len(), src.Len())
+ for i := 0; i < src.Len(); i++ {
+ dst.Index(i).Set(src.Index(i))
+ }
+ sort.SliceStable(dst.Interface(), func(i, j int) bool { return ss.less(dst, i, j) })
+ ss.checkSort(dst)
+ return dst.Interface()
+}
+func (ss sliceSorter) checkSort(v reflect.Value) {
+ start := -1 // Start of a sequence of equal elements.
+ for i := 1; i < v.Len(); i++ {
+ if ss.less(v, i-1, i) {
+ // Check that first and last elements in v[start:i] are equal.
+ if start >= 0 && (ss.less(v, start, i-1) || ss.less(v, i-1, start)) {
+ panic(fmt.Sprintf("incomparable values detected: want equal elements: %v", v.Slice(start, i)))
+ }
+ start = -1
+ } else if start == -1 {
+ start = i
+ }
+ }
+}
+func (ss sliceSorter) less(v reflect.Value, i, j int) bool {
+ vx, vy := v.Index(i), v.Index(j)
+ return ss.fnc.Call([]reflect.Value{vx, vy})[0].Bool()
+}
+
+// SortMaps returns a Transformer option that flattens map[K]V types to be a
+// sorted []struct{K, V}. The less function must be of the form
+// "func(T, T) bool" which is used to sort any map with key K that is
+// assignable to T.
+//
+// Flattening the map into a slice has the property that cmp.Equal is able to
+// use Comparers on K or the K.Equal method if it exists.
+//
+// The less function must be:
+// • Deterministic: less(x, y) == less(x, y)
+// • Irreflexive: !less(x, x)
+// • Transitive: if !less(x, y) and !less(y, z), then !less(x, z)
+// • Total: if x != y, then either less(x, y) or less(y, x)
+//
+// SortMaps can be used in conjunction with EquateEmpty.
+func SortMaps(lessFunc interface{}) cmp.Option {
+ vf := reflect.ValueOf(lessFunc)
+ if !function.IsType(vf.Type(), function.Less) || vf.IsNil() {
+ panic(fmt.Sprintf("invalid less function: %T", lessFunc))
+ }
+ ms := mapSorter{vf.Type().In(0), vf}
+ return cmp.FilterValues(ms.filter, cmp.Transformer("cmpopts.SortMaps", ms.sort))
+}
+
+type mapSorter struct {
+ in reflect.Type // T
+ fnc reflect.Value // func(T, T) bool
+}
+
+func (ms mapSorter) filter(x, y interface{}) bool {
+ vx, vy := reflect.ValueOf(x), reflect.ValueOf(y)
+ return (x != nil && y != nil && vx.Type() == vy.Type()) &&
+ (vx.Kind() == reflect.Map && vx.Type().Key().AssignableTo(ms.in)) &&
+ (vx.Len() != 0 || vy.Len() != 0)
+}
+func (ms mapSorter) sort(x interface{}) interface{} {
+ src := reflect.ValueOf(x)
+ outType := reflect.StructOf([]reflect.StructField{
+ {Name: "K", Type: src.Type().Key()},
+ {Name: "V", Type: src.Type().Elem()},
+ })
+ dst := reflect.MakeSlice(reflect.SliceOf(outType), src.Len(), src.Len())
+ for i, k := range src.MapKeys() {
+ v := reflect.New(outType).Elem()
+ v.Field(0).Set(k)
+ v.Field(1).Set(src.MapIndex(k))
+ dst.Index(i).Set(v)
+ }
+ sort.Slice(dst.Interface(), func(i, j int) bool { return ms.less(dst, i, j) })
+ ms.checkSort(dst)
+ return dst.Interface()
+}
+func (ms mapSorter) checkSort(v reflect.Value) {
+ for i := 1; i < v.Len(); i++ {
+ if !ms.less(v, i-1, i) {
+ panic(fmt.Sprintf("partial order detected: want %v < %v", v.Index(i-1), v.Index(i)))
+ }
+ }
+}
+func (ms mapSorter) less(v reflect.Value, i, j int) bool {
+ vx, vy := v.Index(i).Field(0), v.Index(j).Field(0)
+ return ms.fnc.Call([]reflect.Value{vx, vy})[0].Bool()
+}
projects / dotfiles / .git / blobdiff