yaml/encode.go

217 строки
4.8 KiB
Go

package goyaml
import (
"reflect"
"sort"
"strconv"
)
type encoder struct {
emitter yaml_emitter_t
event yaml_event_t
out []byte
flow bool
}
func newEncoder() (e *encoder) {
e = &encoder{}
e.must(yaml_emitter_initialize(&e.emitter))
yaml_emitter_set_output_string(&e.emitter, &e.out)
e.must(yaml_stream_start_event_initialize(&e.event, yaml_UTF8_ENCODING))
e.emit()
e.must(yaml_document_start_event_initialize(&e.event, nil, nil, true))
e.emit()
return e
}
func (e *encoder) finish() {
e.must(yaml_document_end_event_initialize(&e.event, true))
e.emit()
e.emitter.open_ended = false
e.must(yaml_stream_end_event_initialize(&e.event))
e.emit()
}
func (e *encoder) destroy() {
yaml_emitter_delete(&e.emitter)
}
func (e *encoder) emit() {
// This will internally delete the e.event value.
if !yaml_emitter_emit(&e.emitter, &e.event) && e.event.typ != yaml_DOCUMENT_END_EVENT && e.event.typ != yaml_STREAM_END_EVENT {
e.must(false)
}
}
func (e *encoder) must(ok bool) {
if !ok {
msg := e.emitter.problem
if msg == "" {
msg = "Unknown problem generating YAML content"
}
panic(msg)
}
}
func (e *encoder) marshal(tag string, in reflect.Value) {
var value interface{}
if getter, ok := in.Interface().(Getter); ok {
tag, value = getter.GetYAML()
if value == nil {
e.nilv()
return
}
in = reflect.ValueOf(value)
}
switch in.Kind() {
case reflect.Interface:
if in.IsNil() {
e.nilv()
} else {
e.marshal(tag, in.Elem())
}
case reflect.Map:
e.mapv(tag, in)
case reflect.Ptr:
if in.IsNil() {
e.nilv()
} else {
e.marshal(tag, in.Elem())
}
case reflect.Struct:
e.structv(tag, in)
case reflect.Slice:
e.slicev(tag, in)
case reflect.String:
e.stringv(tag, in)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
e.intv(tag, in)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
e.uintv(tag, in)
case reflect.Float32, reflect.Float64:
e.floatv(tag, in)
case reflect.Bool:
e.boolv(tag, in)
default:
panic("Can't marshal type yet: " + in.Type().String())
}
}
func (e *encoder) mapv(tag string, in reflect.Value) {
e.mappingv(tag, func() {
keys := keyList(in.MapKeys())
sort.Sort(keys)
for _, k := range keys {
e.marshal("", k)
e.marshal("", in.MapIndex(k))
}
})
}
func (e *encoder) structv(tag string, in reflect.Value) {
fields, err := getStructFields(in.Type())
if err != nil {
panic(err)
}
e.mappingv(tag, func() {
for _, info := range fields.List {
value := in.Field(info.Num)
if info.OmitEmpty && isZero(value) {
continue
}
e.marshal("", reflect.ValueOf(info.Key))
e.flow = info.Flow
e.marshal("", value)
}
})
}
func (e *encoder) mappingv(tag string, f func()) {
implicit := tag == ""
style := yaml_BLOCK_MAPPING_STYLE
if e.flow {
e.flow = false
style = yaml_FLOW_MAPPING_STYLE
}
e.must(yaml_mapping_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
e.emit()
f()
e.must(yaml_mapping_end_event_initialize(&e.event))
e.emit()
}
func (e *encoder) slicev(tag string, in reflect.Value) {
implicit := tag == ""
style := yaml_BLOCK_SEQUENCE_STYLE
if e.flow {
e.flow = false
style = yaml_FLOW_SEQUENCE_STYLE
}
e.must(yaml_sequence_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
e.emit()
n := in.Len()
for i := 0; i < n; i++ {
e.marshal("", in.Index(i))
}
e.must(yaml_sequence_end_event_initialize(&e.event))
e.emit()
}
func (e *encoder) stringv(tag string, in reflect.Value) {
var style yaml_scalar_style_t
s := in.String()
if rtag, _ := resolve("", s); rtag != "!!str" {
style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
} else {
style = yaml_PLAIN_SCALAR_STYLE
}
e.emitScalar(s, "", tag, style)
}
func (e *encoder) boolv(tag string, in reflect.Value) {
var s string
if in.Bool() {
s = "true"
} else {
s = "false"
}
e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
}
func (e *encoder) intv(tag string, in reflect.Value) {
s := strconv.FormatInt(in.Int(), 10)
e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
}
func (e *encoder) uintv(tag string, in reflect.Value) {
s := strconv.FormatUint(in.Uint(), 10)
e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
}
func (e *encoder) floatv(tag string, in reflect.Value) {
// FIXME: Handle 64 bits here.
s := strconv.FormatFloat(float64(in.Float()), 'g', -1, 32)
switch s {
case "+Inf":
s = ".inf"
case "-Inf":
s = "-.inf"
case "NaN":
s = ".nan"
}
e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE)
}
func (e *encoder) nilv() {
e.emitScalar("null", "", "", yaml_PLAIN_SCALAR_STYLE)
}
func (e *encoder) emitScalar(value, anchor, tag string, style yaml_scalar_style_t) {
implicit := tag == ""
if !implicit {
style = yaml_PLAIN_SCALAR_STYLE
}
e.must(yaml_scalar_event_initialize(&e.event, []byte(anchor), []byte(tag), []byte(value), implicit, implicit, style))
e.emit()
}