package yaml import ( "encoding" "reflect" "regexp" "sort" "strconv" "strings" "time" ) 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) yaml_emitter_set_unicode(&e.emitter, true) 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" } failf("%s", msg) } } func (e *encoder) marshal(tag string, in reflect.Value) { if !in.IsValid() { e.nilv() return } iface := in.Interface() if m, ok := iface.(Marshaler); ok { v, err := m.MarshalYAML() if err != nil { fail(err) } if v == nil { e.nilv() return } in = reflect.ValueOf(v) } if m, ok := iface.(encoding.TextMarshaler); ok { text, err := m.MarshalText() if err != nil { fail(err) } in = reflect.ValueOf(string(text)) } 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: if in.Type().Elem() == mapItemType { e.itemsv(tag, in) } else { e.slicev(tag, in) } case reflect.String: e.stringv(tag, in) case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: if in.Type() == durationType { e.stringv(tag, reflect.ValueOf(iface.(time.Duration).String())) } else { 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("cannot marshal type: " + 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) itemsv(tag string, in reflect.Value) { e.mappingv(tag, func() { slice := in.Convert(reflect.TypeOf([]MapItem{})).Interface().([]MapItem) for _, item := range slice { e.marshal("", reflect.ValueOf(item.Key)) e.marshal("", reflect.ValueOf(item.Value)) } }) } func (e *encoder) structv(tag string, in reflect.Value) { sinfo, err := getStructInfo(in.Type()) if err != nil { panic(err) } e.mappingv(tag, func() { for _, info := range sinfo.FieldsList { var value reflect.Value if info.Inline == nil { value = in.Field(info.Num) } else { value = in.FieldByIndex(info.Inline) } 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() } // isBase60 returns whether s is in base 60 notation as defined in YAML 1.1. // // The base 60 float notation in YAML 1.1 is a terrible idea and is unsupported // in YAML 1.2 and by this package, but these should be marshalled quoted for // the time being for compatibility with other parsers. func isBase60Float(s string) (result bool) { // Fast path. if s == "" { return false } c := s[0] if !(c == '+' || c == '-' || c >= '0' && c <= '9') || strings.IndexByte(s, ':') < 0 { return false } // Do the full match. return base60float.MatchString(s) } // From http://yaml.org/type/float.html, except the regular expression there // is bogus. In practice parsers do not enforce the "\.[0-9_]*" suffix. var base60float = regexp.MustCompile(`^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+(?:\.[0-9_]*)?$`) func (e *encoder) stringv(tag string, in reflect.Value) { var style yaml_scalar_style_t s := in.String() rtag, rs := resolve("", s) if rtag == yaml_BINARY_TAG { if tag == "" || tag == yaml_STR_TAG { tag = rtag s = rs.(string) } else if tag == yaml_BINARY_TAG { failf("explicitly tagged !!binary data must be base64-encoded") } else { failf("cannot marshal invalid UTF-8 data as %s", shortTag(tag)) } } if tag == "" && (rtag != yaml_STR_TAG || isBase60Float(s)) { style = yaml_DOUBLE_QUOTED_SCALAR_STYLE } else if strings.Contains(s, "\n") { style = yaml_LITERAL_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 == "" e.must(yaml_scalar_event_initialize(&e.event, []byte(anchor), []byte(tag), []byte(value), implicit, implicit, style)) e.emit() }