protobuf-go/internal/mapsort/mapsort.go
Joe Tsai 592e52e148 internal/mapsort: use explicit kind for strings
Rather than handle the string kind in the default case,
explicitly check for the string kind.
Instead, panic with a more useful message for unknown kinds.

Change-Id: I7e205a19658edd62a03f47f5b50a556dd942bf52
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/191579
Reviewed-by: Herbie Ong <herbie@google.com>
2019-09-05 22:07:15 +00:00

44 lines
1.3 KiB
Go

// Copyright 2019 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 file.
// Package mapsort provides sorted access to maps.
package mapsort
import (
"sort"
"google.golang.org/protobuf/reflect/protoreflect"
)
// Range iterates over every map entry in sorted key order,
// calling f for each key and value encountered.
func Range(mapv protoreflect.Map, keyKind protoreflect.Kind, f func(protoreflect.MapKey, protoreflect.Value) bool) {
var keys []protoreflect.MapKey
mapv.Range(func(key protoreflect.MapKey, _ protoreflect.Value) bool {
keys = append(keys, key)
return true
})
sort.Slice(keys, func(i, j int) bool {
switch keyKind {
case protoreflect.BoolKind:
return !keys[i].Bool() && keys[j].Bool()
case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind,
protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
return keys[i].Int() < keys[j].Int()
case protoreflect.Uint32Kind, protoreflect.Fixed32Kind,
protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
return keys[i].Uint() < keys[j].Uint()
case protoreflect.StringKind:
return keys[i].String() < keys[j].String()
default:
panic("invalid kind: " + keyKind.String())
}
})
for _, key := range keys {
if !f(key, mapv.Get(key)) {
break
}
}
}