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authorMichael Muré <batolettre@gmail.com>2018-07-20 15:46:14 +0200
committerMichael Muré <batolettre@gmail.com>2018-07-20 15:46:14 +0200
commite89f87624f27b7b98efc959bd96e260ac86f9236 (patch)
tree6561a1c1eb1660736c48d668f43ccaf67cce19a2 /vendor/gopkg.in/yaml.v2/decode.go
parent1dd5118eebe0e993d55ae5433cb2dcfd2764bf4f (diff)
downloadgit-bug-e89f87624f27b7b98efc959bd96e260ac86f9236.tar.gz
generate markdown documentation
Diffstat (limited to 'vendor/gopkg.in/yaml.v2/decode.go')
-rw-r--r--vendor/gopkg.in/yaml.v2/decode.go775
1 files changed, 775 insertions, 0 deletions
diff --git a/vendor/gopkg.in/yaml.v2/decode.go b/vendor/gopkg.in/yaml.v2/decode.go
new file mode 100644
index 00000000..e4e56e28
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v2/decode.go
@@ -0,0 +1,775 @@
+package yaml
+
+import (
+ "encoding"
+ "encoding/base64"
+ "fmt"
+ "io"
+ "math"
+ "reflect"
+ "strconv"
+ "time"
+)
+
+const (
+ documentNode = 1 << iota
+ mappingNode
+ sequenceNode
+ scalarNode
+ aliasNode
+)
+
+type node struct {
+ kind int
+ line, column int
+ tag string
+ // For an alias node, alias holds the resolved alias.
+ alias *node
+ value string
+ implicit bool
+ children []*node
+ anchors map[string]*node
+}
+
+// ----------------------------------------------------------------------------
+// Parser, produces a node tree out of a libyaml event stream.
+
+type parser struct {
+ parser yaml_parser_t
+ event yaml_event_t
+ doc *node
+ doneInit bool
+}
+
+func newParser(b []byte) *parser {
+ p := parser{}
+ if !yaml_parser_initialize(&p.parser) {
+ panic("failed to initialize YAML emitter")
+ }
+ if len(b) == 0 {
+ b = []byte{'\n'}
+ }
+ yaml_parser_set_input_string(&p.parser, b)
+ return &p
+}
+
+func newParserFromReader(r io.Reader) *parser {
+ p := parser{}
+ if !yaml_parser_initialize(&p.parser) {
+ panic("failed to initialize YAML emitter")
+ }
+ yaml_parser_set_input_reader(&p.parser, r)
+ return &p
+}
+
+func (p *parser) init() {
+ if p.doneInit {
+ return
+ }
+ p.expect(yaml_STREAM_START_EVENT)
+ p.doneInit = true
+}
+
+func (p *parser) destroy() {
+ if p.event.typ != yaml_NO_EVENT {
+ yaml_event_delete(&p.event)
+ }
+ yaml_parser_delete(&p.parser)
+}
+
+// expect consumes an event from the event stream and
+// checks that it's of the expected type.
+func (p *parser) expect(e yaml_event_type_t) {
+ if p.event.typ == yaml_NO_EVENT {
+ if !yaml_parser_parse(&p.parser, &p.event) {
+ p.fail()
+ }
+ }
+ if p.event.typ == yaml_STREAM_END_EVENT {
+ failf("attempted to go past the end of stream; corrupted value?")
+ }
+ if p.event.typ != e {
+ p.parser.problem = fmt.Sprintf("expected %s event but got %s", e, p.event.typ)
+ p.fail()
+ }
+ yaml_event_delete(&p.event)
+ p.event.typ = yaml_NO_EVENT
+}
+
+// peek peeks at the next event in the event stream,
+// puts the results into p.event and returns the event type.
+func (p *parser) peek() yaml_event_type_t {
+ if p.event.typ != yaml_NO_EVENT {
+ return p.event.typ
+ }
+ if !yaml_parser_parse(&p.parser, &p.event) {
+ p.fail()
+ }
+ return p.event.typ
+}
+
+func (p *parser) fail() {
+ var where string
+ var line int
+ if p.parser.problem_mark.line != 0 {
+ line = p.parser.problem_mark.line
+ // Scanner errors don't iterate line before returning error
+ if p.parser.error == yaml_SCANNER_ERROR {
+ line++
+ }
+ } else if p.parser.context_mark.line != 0 {
+ line = p.parser.context_mark.line
+ }
+ if line != 0 {
+ where = "line " + strconv.Itoa(line) + ": "
+ }
+ var msg string
+ if len(p.parser.problem) > 0 {
+ msg = p.parser.problem
+ } else {
+ msg = "unknown problem parsing YAML content"
+ }
+ failf("%s%s", where, msg)
+}
+
+func (p *parser) anchor(n *node, anchor []byte) {
+ if anchor != nil {
+ p.doc.anchors[string(anchor)] = n
+ }
+}
+
+func (p *parser) parse() *node {
+ p.init()
+ switch p.peek() {
+ case yaml_SCALAR_EVENT:
+ return p.scalar()
+ case yaml_ALIAS_EVENT:
+ return p.alias()
+ case yaml_MAPPING_START_EVENT:
+ return p.mapping()
+ case yaml_SEQUENCE_START_EVENT:
+ return p.sequence()
+ case yaml_DOCUMENT_START_EVENT:
+ return p.document()
+ case yaml_STREAM_END_EVENT:
+ // Happens when attempting to decode an empty buffer.
+ return nil
+ default:
+ panic("attempted to parse unknown event: " + p.event.typ.String())
+ }
+}
+
+func (p *parser) node(kind int) *node {
+ return &node{
+ kind: kind,
+ line: p.event.start_mark.line,
+ column: p.event.start_mark.column,
+ }
+}
+
+func (p *parser) document() *node {
+ n := p.node(documentNode)
+ n.anchors = make(map[string]*node)
+ p.doc = n
+ p.expect(yaml_DOCUMENT_START_EVENT)
+ n.children = append(n.children, p.parse())
+ p.expect(yaml_DOCUMENT_END_EVENT)
+ return n
+}
+
+func (p *parser) alias() *node {
+ n := p.node(aliasNode)
+ n.value = string(p.event.anchor)
+ n.alias = p.doc.anchors[n.value]
+ if n.alias == nil {
+ failf("unknown anchor '%s' referenced", n.value)
+ }
+ p.expect(yaml_ALIAS_EVENT)
+ return n
+}
+
+func (p *parser) scalar() *node {
+ n := p.node(scalarNode)
+ n.value = string(p.event.value)
+ n.tag = string(p.event.tag)
+ n.implicit = p.event.implicit
+ p.anchor(n, p.event.anchor)
+ p.expect(yaml_SCALAR_EVENT)
+ return n
+}
+
+func (p *parser) sequence() *node {
+ n := p.node(sequenceNode)
+ p.anchor(n, p.event.anchor)
+ p.expect(yaml_SEQUENCE_START_EVENT)
+ for p.peek() != yaml_SEQUENCE_END_EVENT {
+ n.children = append(n.children, p.parse())
+ }
+ p.expect(yaml_SEQUENCE_END_EVENT)
+ return n
+}
+
+func (p *parser) mapping() *node {
+ n := p.node(mappingNode)
+ p.anchor(n, p.event.anchor)
+ p.expect(yaml_MAPPING_START_EVENT)
+ for p.peek() != yaml_MAPPING_END_EVENT {
+ n.children = append(n.children, p.parse(), p.parse())
+ }
+ p.expect(yaml_MAPPING_END_EVENT)
+ return n
+}
+
+// ----------------------------------------------------------------------------
+// Decoder, unmarshals a node into a provided value.
+
+type decoder struct {
+ doc *node
+ aliases map[*node]bool
+ mapType reflect.Type
+ terrors []string
+ strict bool
+}
+
+var (
+ mapItemType = reflect.TypeOf(MapItem{})
+ durationType = reflect.TypeOf(time.Duration(0))
+ defaultMapType = reflect.TypeOf(map[interface{}]interface{}{})
+ ifaceType = defaultMapType.Elem()
+ timeType = reflect.TypeOf(time.Time{})
+ ptrTimeType = reflect.TypeOf(&time.Time{})
+)
+
+func newDecoder(strict bool) *decoder {
+ d := &decoder{mapType: defaultMapType, strict: strict}
+ d.aliases = make(map[*node]bool)
+ return d
+}
+
+func (d *decoder) terror(n *node, tag string, out reflect.Value) {
+ if n.tag != "" {
+ tag = n.tag
+ }
+ value := n.value
+ if tag != yaml_SEQ_TAG && tag != yaml_MAP_TAG {
+ if len(value) > 10 {
+ value = " `" + value[:7] + "...`"
+ } else {
+ value = " `" + value + "`"
+ }
+ }
+ d.terrors = append(d.terrors, fmt.Sprintf("line %d: cannot unmarshal %s%s into %s", n.line+1, shortTag(tag), value, out.Type()))
+}
+
+func (d *decoder) callUnmarshaler(n *node, u Unmarshaler) (good bool) {
+ terrlen := len(d.terrors)
+ err := u.UnmarshalYAML(func(v interface{}) (err error) {
+ defer handleErr(&err)
+ d.unmarshal(n, reflect.ValueOf(v))
+ if len(d.terrors) > terrlen {
+ issues := d.terrors[terrlen:]
+ d.terrors = d.terrors[:terrlen]
+ return &TypeError{issues}
+ }
+ return nil
+ })
+ if e, ok := err.(*TypeError); ok {
+ d.terrors = append(d.terrors, e.Errors...)
+ return false
+ }
+ if err != nil {
+ fail(err)
+ }
+ return true
+}
+
+// d.prepare initializes and dereferences pointers and calls UnmarshalYAML
+// if a value is found to implement it.
+// It returns the initialized and dereferenced out value, whether
+// unmarshalling was already done by UnmarshalYAML, and if so whether
+// its types unmarshalled appropriately.
+//
+// If n holds a null value, prepare returns before doing anything.
+func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unmarshaled, good bool) {
+ if n.tag == yaml_NULL_TAG || n.kind == scalarNode && n.tag == "" && (n.value == "null" || n.value == "~" || n.value == "" && n.implicit) {
+ return out, false, false
+ }
+ again := true
+ for again {
+ again = false
+ if out.Kind() == reflect.Ptr {
+ if out.IsNil() {
+ out.Set(reflect.New(out.Type().Elem()))
+ }
+ out = out.Elem()
+ again = true
+ }
+ if out.CanAddr() {
+ if u, ok := out.Addr().Interface().(Unmarshaler); ok {
+ good = d.callUnmarshaler(n, u)
+ return out, true, good
+ }
+ }
+ }
+ return out, false, false
+}
+
+func (d *decoder) unmarshal(n *node, out reflect.Value) (good bool) {
+ switch n.kind {
+ case documentNode:
+ return d.document(n, out)
+ case aliasNode:
+ return d.alias(n, out)
+ }
+ out, unmarshaled, good := d.prepare(n, out)
+ if unmarshaled {
+ return good
+ }
+ switch n.kind {
+ case scalarNode:
+ good = d.scalar(n, out)
+ case mappingNode:
+ good = d.mapping(n, out)
+ case sequenceNode:
+ good = d.sequence(n, out)
+ default:
+ panic("internal error: unknown node kind: " + strconv.Itoa(n.kind))
+ }
+ return good
+}
+
+func (d *decoder) document(n *node, out reflect.Value) (good bool) {
+ if len(n.children) == 1 {
+ d.doc = n
+ d.unmarshal(n.children[0], out)
+ return true
+ }
+ return false
+}
+
+func (d *decoder) alias(n *node, out reflect.Value) (good bool) {
+ if d.aliases[n] {
+ // TODO this could actually be allowed in some circumstances.
+ failf("anchor '%s' value contains itself", n.value)
+ }
+ d.aliases[n] = true
+ good = d.unmarshal(n.alias, out)
+ delete(d.aliases, n)
+ return good
+}
+
+var zeroValue reflect.Value
+
+func resetMap(out reflect.Value) {
+ for _, k := range out.MapKeys() {
+ out.SetMapIndex(k, zeroValue)
+ }
+}
+
+func (d *decoder) scalar(n *node, out reflect.Value) bool {
+ var tag string
+ var resolved interface{}
+ if n.tag == "" && !n.implicit {
+ tag = yaml_STR_TAG
+ resolved = n.value
+ } else {
+ tag, resolved = resolve(n.tag, n.value)
+ if tag == yaml_BINARY_TAG {
+ data, err := base64.StdEncoding.DecodeString(resolved.(string))
+ if err != nil {
+ failf("!!binary value contains invalid base64 data")
+ }
+ resolved = string(data)
+ }
+ }
+ if resolved == nil {
+ if out.Kind() == reflect.Map && !out.CanAddr() {
+ resetMap(out)
+ } else {
+ out.Set(reflect.Zero(out.Type()))
+ }
+ return true
+ }
+ if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+ // We've resolved to exactly the type we want, so use that.
+ out.Set(resolvedv)
+ return true
+ }
+ // Perhaps we can use the value as a TextUnmarshaler to
+ // set its value.
+ if out.CanAddr() {
+ u, ok := out.Addr().Interface().(encoding.TextUnmarshaler)
+ if ok {
+ var text []byte
+ if tag == yaml_BINARY_TAG {
+ text = []byte(resolved.(string))
+ } else {
+ // We let any value be unmarshaled into TextUnmarshaler.
+ // That might be more lax than we'd like, but the
+ // TextUnmarshaler itself should bowl out any dubious values.
+ text = []byte(n.value)
+ }
+ err := u.UnmarshalText(text)
+ if err != nil {
+ fail(err)
+ }
+ return true
+ }
+ }
+ switch out.Kind() {
+ case reflect.String:
+ if tag == yaml_BINARY_TAG {
+ out.SetString(resolved.(string))
+ return true
+ }
+ if resolved != nil {
+ out.SetString(n.value)
+ return true
+ }
+ case reflect.Interface:
+ if resolved == nil {
+ out.Set(reflect.Zero(out.Type()))
+ } else if tag == yaml_TIMESTAMP_TAG {
+ // It looks like a timestamp but for backward compatibility
+ // reasons we set it as a string, so that code that unmarshals
+ // timestamp-like values into interface{} will continue to
+ // see a string and not a time.Time.
+ // TODO(v3) Drop this.
+ out.Set(reflect.ValueOf(n.value))
+ } else {
+ out.Set(reflect.ValueOf(resolved))
+ }
+ return true
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ switch resolved := resolved.(type) {
+ case int:
+ if !out.OverflowInt(int64(resolved)) {
+ out.SetInt(int64(resolved))
+ return true
+ }
+ case int64:
+ if !out.OverflowInt(resolved) {
+ out.SetInt(resolved)
+ return true
+ }
+ case uint64:
+ if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
+ out.SetInt(int64(resolved))
+ return true
+ }
+ case float64:
+ if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
+ out.SetInt(int64(resolved))
+ return true
+ }
+ case string:
+ if out.Type() == durationType {
+ d, err := time.ParseDuration(resolved)
+ if err == nil {
+ out.SetInt(int64(d))
+ return true
+ }
+ }
+ }
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ switch resolved := resolved.(type) {
+ case int:
+ if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
+ out.SetUint(uint64(resolved))
+ return true
+ }
+ case int64:
+ if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
+ out.SetUint(uint64(resolved))
+ return true
+ }
+ case uint64:
+ if !out.OverflowUint(uint64(resolved)) {
+ out.SetUint(uint64(resolved))
+ return true
+ }
+ case float64:
+ if resolved <= math.MaxUint64 && !out.OverflowUint(uint64(resolved)) {
+ out.SetUint(uint64(resolved))
+ return true
+ }
+ }
+ case reflect.Bool:
+ switch resolved := resolved.(type) {
+ case bool:
+ out.SetBool(resolved)
+ return true
+ }
+ case reflect.Float32, reflect.Float64:
+ switch resolved := resolved.(type) {
+ case int:
+ out.SetFloat(float64(resolved))
+ return true
+ case int64:
+ out.SetFloat(float64(resolved))
+ return true
+ case uint64:
+ out.SetFloat(float64(resolved))
+ return true
+ case float64:
+ out.SetFloat(resolved)
+ return true
+ }
+ case reflect.Struct:
+ if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+ out.Set(resolvedv)
+ return true
+ }
+ case reflect.Ptr:
+ if out.Type().Elem() == reflect.TypeOf(resolved) {
+ // TODO DOes this make sense? When is out a Ptr except when decoding a nil value?
+ elem := reflect.New(out.Type().Elem())
+ elem.Elem().Set(reflect.ValueOf(resolved))
+ out.Set(elem)
+ return true
+ }
+ }
+ d.terror(n, tag, out)
+ return false
+}
+
+func settableValueOf(i interface{}) reflect.Value {
+ v := reflect.ValueOf(i)
+ sv := reflect.New(v.Type()).Elem()
+ sv.Set(v)
+ return sv
+}
+
+func (d *decoder) sequence(n *node, out reflect.Value) (good bool) {
+ l := len(n.children)
+
+ var iface reflect.Value
+ switch out.Kind() {
+ case reflect.Slice:
+ out.Set(reflect.MakeSlice(out.Type(), l, l))
+ case reflect.Array:
+ if l != out.Len() {
+ failf("invalid array: want %d elements but got %d", out.Len(), l)
+ }
+ case reflect.Interface:
+ // No type hints. Will have to use a generic sequence.
+ iface = out
+ out = settableValueOf(make([]interface{}, l))
+ default:
+ d.terror(n, yaml_SEQ_TAG, out)
+ return false
+ }
+ et := out.Type().Elem()
+
+ j := 0
+ for i := 0; i < l; i++ {
+ e := reflect.New(et).Elem()
+ if ok := d.unmarshal(n.children[i], e); ok {
+ out.Index(j).Set(e)
+ j++
+ }
+ }
+ if out.Kind() != reflect.Array {
+ out.Set(out.Slice(0, j))
+ }
+ if iface.IsValid() {
+ iface.Set(out)
+ }
+ return true
+}
+
+func (d *decoder) mapping(n *node, out reflect.Value) (good bool) {
+ switch out.Kind() {
+ case reflect.Struct:
+ return d.mappingStruct(n, out)
+ case reflect.Slice:
+ return d.mappingSlice(n, out)
+ case reflect.Map:
+ // okay
+ case reflect.Interface:
+ if d.mapType.Kind() == reflect.Map {
+ iface := out
+ out = reflect.MakeMap(d.mapType)
+ iface.Set(out)
+ } else {
+ slicev := reflect.New(d.mapType).Elem()
+ if !d.mappingSlice(n, slicev) {
+ return false
+ }
+ out.Set(slicev)
+ return true
+ }
+ default:
+ d.terror(n, yaml_MAP_TAG, out)
+ return false
+ }
+ outt := out.Type()
+ kt := outt.Key()
+ et := outt.Elem()
+
+ mapType := d.mapType
+ if outt.Key() == ifaceType && outt.Elem() == ifaceType {
+ d.mapType = outt
+ }
+
+ if out.IsNil() {
+ out.Set(reflect.MakeMap(outt))
+ }
+ l := len(n.children)
+ for i := 0; i < l; i += 2 {
+ if isMerge(n.children[i]) {
+ d.merge(n.children[i+1], out)
+ continue
+ }
+ k := reflect.New(kt).Elem()
+ if d.unmarshal(n.children[i], k) {
+ kkind := k.Kind()
+ if kkind == reflect.Interface {
+ kkind = k.Elem().Kind()
+ }
+ if kkind == reflect.Map || kkind == reflect.Slice {
+ failf("invalid map key: %#v", k.Interface())
+ }
+ e := reflect.New(et).Elem()
+ if d.unmarshal(n.children[i+1], e) {
+ d.setMapIndex(n.children[i+1], out, k, e)
+ }
+ }
+ }
+ d.mapType = mapType
+ return true
+}
+
+func (d *decoder) setMapIndex(n *node, out, k, v reflect.Value) {
+ if d.strict && out.MapIndex(k) != zeroValue {
+ d.terrors = append(d.terrors, fmt.Sprintf("line %d: key %#v already set in map", n.line+1, k.Interface()))
+ return
+ }
+ out.SetMapIndex(k, v)
+}
+
+func (d *decoder) mappingSlice(n *node, out reflect.Value) (good bool) {
+ outt := out.Type()
+ if outt.Elem() != mapItemType {
+ d.terror(n, yaml_MAP_TAG, out)
+ return false
+ }
+
+ mapType := d.mapType
+ d.mapType = outt
+
+ var slice []MapItem
+ var l = len(n.children)
+ for i := 0; i < l; i += 2 {
+ if isMerge(n.children[i]) {
+ d.merge(n.children[i+1], out)
+ continue
+ }
+ item := MapItem{}
+ k := reflect.ValueOf(&item.Key).Elem()
+ if d.unmarshal(n.children[i], k) {
+ v := reflect.ValueOf(&item.Value).Elem()
+ if d.unmarshal(n.children[i+1], v) {
+ slice = append(slice, item)
+ }
+ }
+ }
+ out.Set(reflect.ValueOf(slice))
+ d.mapType = mapType
+ return true
+}
+
+func (d *decoder) mappingStruct(n *node, out reflect.Value) (good bool) {
+ sinfo, err := getStructInfo(out.Type())
+ if err != nil {
+ panic(err)
+ }
+ name := settableValueOf("")
+ l := len(n.children)
+
+ var inlineMap reflect.Value
+ var elemType reflect.Type
+ if sinfo.InlineMap != -1 {
+ inlineMap = out.Field(sinfo.InlineMap)
+ inlineMap.Set(reflect.New(inlineMap.Type()).Elem())
+ elemType = inlineMap.Type().Elem()
+ }
+
+ var doneFields []bool
+ if d.strict {
+ doneFields = make([]bool, len(sinfo.FieldsList))
+ }
+ for i := 0; i < l; i += 2 {
+ ni := n.children[i]
+ if isMerge(ni) {
+ d.merge(n.children[i+1], out)
+ continue
+ }
+ if !d.unmarshal(ni, name) {
+ continue
+ }
+ if info, ok := sinfo.FieldsMap[name.String()]; ok {
+ if d.strict {
+ if doneFields[info.Id] {
+ d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s already set in type %s", ni.line+1, name.String(), out.Type()))
+ continue
+ }
+ doneFields[info.Id] = true
+ }
+ var field reflect.Value
+ if info.Inline == nil {
+ field = out.Field(info.Num)
+ } else {
+ field = out.FieldByIndex(info.Inline)
+ }
+ d.unmarshal(n.children[i+1], field)
+ } else if sinfo.InlineMap != -1 {
+ if inlineMap.IsNil() {
+ inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
+ }
+ value := reflect.New(elemType).Elem()
+ d.unmarshal(n.children[i+1], value)
+ d.setMapIndex(n.children[i+1], inlineMap, name, value)
+ } else if d.strict {
+ d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in type %s", ni.line+1, name.String(), out.Type()))
+ }
+ }
+ return true
+}
+
+func failWantMap() {
+ failf("map merge requires map or sequence of maps as the value")
+}
+
+func (d *decoder) merge(n *node, out reflect.Value) {
+ switch n.kind {
+ case mappingNode:
+ d.unmarshal(n, out)
+ case aliasNode:
+ an, ok := d.doc.anchors[n.value]
+ if ok && an.kind != mappingNode {
+ failWantMap()
+ }
+ d.unmarshal(n, out)
+ case sequenceNode:
+ // Step backwards as earlier nodes take precedence.
+ for i := len(n.children) - 1; i >= 0; i-- {
+ ni := n.children[i]
+ if ni.kind == aliasNode {
+ an, ok := d.doc.anchors[ni.value]
+ if ok && an.kind != mappingNode {
+ failWantMap()
+ }
+ } else if ni.kind != mappingNode {
+ failWantMap()
+ }
+ d.unmarshal(ni, out)
+ }
+ default:
+ failWantMap()
+ }
+}
+
+func isMerge(n *node) bool {
+ return n.kind == scalarNode && n.value == "<<" && (n.implicit == true || n.tag == yaml_MERGE_TAG)
+}