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dex/vendor/github.com/kylelemons/godebug/pretty/structure.go
Stephan Renatus 076cd77469
run 'go get -u; make revendor'
Signed-off-by: Stephan Renatus <srenatus@chef.io>
2019-07-31 08:09:38 +02:00

224 lines
4.4 KiB
Go

// Copyright 2013 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package pretty
import (
"bufio"
"bytes"
"fmt"
"io"
"strconv"
"strings"
)
// a formatter stores stateful formatting information as well as being
// an io.Writer for simplicity.
type formatter struct {
*bufio.Writer
*Config
// Self-referential structure tracking
tagNumbers map[int]int // tagNumbers[id] = <#n>
}
// newFormatter creates a new buffered formatter. For the output to be written
// to the given writer, this must be accompanied by a call to write (or Flush).
func newFormatter(cfg *Config, w io.Writer) *formatter {
return &formatter{
Writer: bufio.NewWriter(w),
Config: cfg,
tagNumbers: make(map[int]int),
}
}
func (f *formatter) write(n node) {
defer f.Flush()
n.format(f, "")
}
func (f *formatter) tagFor(id int) int {
if tag, ok := f.tagNumbers[id]; ok {
return tag
}
if f.tagNumbers == nil {
return 0
}
tag := len(f.tagNumbers) + 1
f.tagNumbers[id] = tag
return tag
}
type node interface {
format(f *formatter, indent string)
}
func (f *formatter) compactString(n node) string {
switch k := n.(type) {
case stringVal:
return string(k)
case rawVal:
return string(k)
}
buf := new(bytes.Buffer)
f2 := newFormatter(&Config{Compact: true}, buf)
f2.tagNumbers = f.tagNumbers // reuse tagNumbers just in case
f2.write(n)
return buf.String()
}
type stringVal string
func (str stringVal) format(f *formatter, indent string) {
f.WriteString(strconv.Quote(string(str)))
}
type rawVal string
func (r rawVal) format(f *formatter, indent string) {
f.WriteString(string(r))
}
type keyval struct {
key string
val node
}
type keyvals []keyval
func (l keyvals) format(f *formatter, indent string) {
f.WriteByte('{')
switch {
case f.Compact:
// All on one line:
for i, kv := range l {
if i > 0 {
f.WriteByte(',')
}
f.WriteString(kv.key)
f.WriteByte(':')
kv.val.format(f, indent)
}
case f.Diffable:
f.WriteByte('\n')
inner := indent + " "
// Each value gets its own line:
for _, kv := range l {
f.WriteString(inner)
f.WriteString(kv.key)
f.WriteString(": ")
kv.val.format(f, inner)
f.WriteString(",\n")
}
f.WriteString(indent)
default:
keyWidth := 0
for _, kv := range l {
if kw := len(kv.key); kw > keyWidth {
keyWidth = kw
}
}
alignKey := indent + " "
alignValue := strings.Repeat(" ", keyWidth)
inner := alignKey + alignValue + " "
// First and last line shared with bracket:
for i, kv := range l {
if i > 0 {
f.WriteString(",\n")
f.WriteString(alignKey)
}
f.WriteString(kv.key)
f.WriteString(": ")
f.WriteString(alignValue[len(kv.key):])
kv.val.format(f, inner)
}
}
f.WriteByte('}')
}
type list []node
func (l list) format(f *formatter, indent string) {
if max := f.ShortList; max > 0 {
short := f.compactString(l)
if len(short) <= max {
f.WriteString(short)
return
}
}
f.WriteByte('[')
switch {
case f.Compact:
// All on one line:
for i, v := range l {
if i > 0 {
f.WriteByte(',')
}
v.format(f, indent)
}
case f.Diffable:
f.WriteByte('\n')
inner := indent + " "
// Each value gets its own line:
for _, v := range l {
f.WriteString(inner)
v.format(f, inner)
f.WriteString(",\n")
}
f.WriteString(indent)
default:
inner := indent + " "
// First and last line shared with bracket:
for i, v := range l {
if i > 0 {
f.WriteString(",\n")
f.WriteString(inner)
}
v.format(f, inner)
}
}
f.WriteByte(']')
}
type ref struct {
id int
}
func (r ref) format(f *formatter, indent string) {
fmt.Fprintf(f, "<see #%d>", f.tagFor(r.id))
}
type target struct {
id int
value node
}
func (t target) format(f *formatter, indent string) {
tag := fmt.Sprintf("<#%d> ", f.tagFor(t.id))
switch {
case f.Diffable, f.Compact:
// no indent changes
default:
indent += strings.Repeat(" ", len(tag))
}
f.WriteString(tag)
t.value.format(f, indent)
}