Merge pull request #1 from taustgen-wework/v3

Updates to yaml allowing decoding into structs and maintaining field positions and comments.

Author: taustgen-wework

decode.go

@@ -851,7 +851,43 @@ func isStringMap(n *Node) bool {
 	return true
 }
 
+//
+
+// StuctMeta can be added to a struct and  holds the comments and field ordering for that struct
+type StructMeta interface {
+	// Returns the fields in proper order
+	GetFieldsIndex() []fieldInfo
+
+	// Returns the head line and foot comments for the field
+	GetComments() [][]comments
+}
+
+// structMeta implements the StructMeta interface
+type structMeta struct {
+	FieldsIndex []fieldInfo
+	Comments    [][]comments
+}
+
+// comments holds the 3 possible comments for a node.
+type comments struct {
+	head []byte
+	line []byte
+	foot []byte
+}
+
+const yamlMeta = "yaml_meta"
+
+func (s *structMeta) GetFieldsIndex() []fieldInfo {
+	return s.FieldsIndex
+}
+
+func (s *structMeta) GetComments() [][]comments {
+	return s.Comments
+}
+
 func (d *decoder) mappingStruct(n *Node, out reflect.Value) (good bool) {
+	fieldsIndex := make([]fieldInfo, 0)
+	com := make([][]comments, 0)
 	sinfo, err := getStructInfo(out.Type())
 	if err != nil {
 		panic(err)
@@ -900,6 +936,21 @@ func (d *decoder) mappingStruct(n *Node, out reflect.Value) (good bool) {
 				field = d.fieldByIndex(n, out, info.Inline)
 			}
 			d.unmarshal(n.Content[i+1], field)
+
+			keyComments := comments{
+				head: []byte(ni.HeadComment),
+				line: []byte(ni.LineComment),
+				foot: []byte(ni.FootComment),
+			}
+			valComments := comments{
+				head: []byte(n.Content[i+1].HeadComment),
+				line: []byte(n.Content[i+1].LineComment),
+				foot: []byte(n.Content[i+1].FootComment),
+			}
+
+			fieldsIndex = append(fieldsIndex, info)
+			com = append(com, []comments{keyComments, valComments})
+
 		} else if sinfo.InlineMap != -1 {
 			if inlineMap.IsNil() {
 				inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
@@ -911,6 +962,18 @@ func (d *decoder) mappingStruct(n *Node, out reflect.Value) (good bool) {
 			d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in type %s", ni.Line, name.String(), out.Type()))
 		}
 	}
+
+	//  This change is populating yamlMeta field with the with field order and comments
+	if idxInfo, idxOk := sinfo.FieldsMap[yamlMeta]; idxOk {
+		idxField := out.Field(idxInfo.Num)
+		fValue := &structMeta{
+			FieldsIndex: fieldsIndex,
+			Comments:    com,
+		}
+
+		idxField.Set(reflect.ValueOf(fValue))
+	}
+
 	return true
 }
 

emitterc.go

@@ -241,7 +241,7 @@ func yaml_emitter_increase_indent(emitter *yaml_emitter_t, flow, indentless bool
 			emitter.indent += 2
 		} else {
 			// Everything else aligns to the chosen indentation.
-			emitter.indent = emitter.best_indent*((emitter.indent+emitter.best_indent)/emitter.best_indent)
+			emitter.indent = emitter.best_indent * ((emitter.indent + emitter.best_indent) / emitter.best_indent)
 		}
 	}
 	return true
@@ -727,14 +727,17 @@ func yaml_emitter_emit_flow_mapping_value(emitter *yaml_emitter_t, event *yaml_e
 
 // Expect a block item node.
 func yaml_emitter_emit_block_sequence_item(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
-	if first {
+	if first && !emitter.sequenceUndent {
 		if !yaml_emitter_increase_indent(emitter, false, false) {
 			return false
 		}
 	}
 	if event.typ == yaml_SEQUENCE_END_EVENT {
-		emitter.indent = emitter.indents[len(emitter.indents)-1]
-		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		if !emitter.sequenceUndent {
+			emitter.indent = emitter.indents[len(emitter.indents)-1]
+			emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		}
+
 		emitter.state = emitter.states[len(emitter.states)-1]
 		emitter.states = emitter.states[:len(emitter.states)-1]
 		return true
@@ -1612,7 +1615,6 @@ func yaml_emitter_write_plain_scalar(emitter *yaml_emitter_t, value []byte, allo
 			return false
 		}
 	}
-
 	spaces := false
 	breaks := false
 	for i := 0; i < len(value); {