func encode(e *xml.Encoder, p parser.Interface) error {
for {
if err := p.Next(); err != nil {
if err == io.EOF {
break
} else {
return err
}
}
if p.IsLeaf() {
if err := e.EncodeToken(getCharData(p)); err != nil {
return err
}
} else {
name := getName(p)
if err := e.EncodeToken(xml.StartElement{Name: name}); err != nil {
return err
}
p.Down()
if err := encode(e, p); err != nil {
return err
}
p.Up()
if err := e.EncodeToken(xml.EndElement{Name: name}); err != nil {
return err
}
}
}
return nil
}
func encode(p parser.Interface) (interface{}, error) {
var fields = make(map[string]interface{})
var list []interface{}
for {
if err := p.Next(); err != nil {
if err == io.EOF {
if len(fields) > 0 {
return fields, nil
}
if list != nil {
return list, nil
}
return nil, nil
}
return nil, err
}
if p.IsLeaf() {
if v, err := p.Int(); err == nil {
return v, nil
}
if v, err := p.Uint(); err == nil {
return v, nil
}
if v, err := p.Double(); err == nil {
return v, nil
}
if v, err := p.Bool(); err == nil {
return v, nil
}
if v, err := p.String(); err == nil {
return v, nil
}
if v, err := p.Bytes(); err == nil {
return base64.StdEncoding.EncodeToString(v), nil
}
return nil, nil
}
if _, err := p.Int(); err == nil {
p.Down()
item, err := encode(p)
if err != nil {
return nil, err
}
p.Up()
list = append(list, item)
continue
}
name, err := p.String()
if err != nil {
return nil, err
}
p.Down()
value, err := encode(p)
if err != nil {
return nil, err
}
p.Up()
fields[name] = value
}
}
//RandomWalk does a random walk of the parser, given two probabilities.
// next is passed to r.Intn and when a zero value is returned the Next method on the parser is called.
// down is passed to r.Intn and when a non zero value is returned the Down method on the parser is called.
//RandomWalk is great for testing that the implemented parser can handle random skipping of parts of the tree.
func RandomWalk(p parser.Interface, r Rand, next, down int) Nodes {
a := make(Nodes, 0)
for {
if r.Intn(next) == 0 {
break
}
if err := p.Next(); err != nil {
if err == io.EOF {
break
} else {
panic(err)
}
}
value := getValue(p)
if p.IsLeaf() {
a = append(a, Node{fmt.Sprintf("%#v", value), nil})
} else {
name := fmt.Sprintf("%#v", value)
var v Nodes
if r.Intn(down) != 0 {
p.Down()
v = RandomWalk(p, r, next, down)
p.Up()
}
a = append(a, Node{name, v})
}
}
return a
}
func deriv(auto *Auto, current int, tree parser.Interface) (int, error) {
for {
if !auto.escapables[current] {
return current, nil
}
if err := tree.Next(); err != nil {
if err == io.EOF {
break
} else {
return 0, err
}
}
callTree := auto.calls[current]
childState, stackElm, err := callTree.Eval(tree)
if err != nil {
return 0, err
}
if !tree.IsLeaf() {
tree.Down()
childState, err = deriv(auto, childState, tree)
if err != nil {
return 0, err
}
tree.Up()
}
nullIndex := auto.stateToNullable[childState]
current = auto.returns[stackElm].lookup(nullIndex)
}
return current, nil
}
func deriv(refs ast.RefLookup, patterns []*ast.Pattern, tree parser.Interface) ([]*ast.Pattern, error) {
var resPatterns []*ast.Pattern = patterns
for {
if !escapable(resPatterns) {
return resPatterns, nil
}
if err := tree.Next(); err != nil {
if err == io.EOF {
break
} else {
return nil, err
}
}
childPatterns, err := derivCalls(refs, resPatterns, tree)
if err != nil {
return nil, err
}
if tree.IsLeaf() {
//do nothing
} else {
tree.Down()
zchild, zi := zip(childPatterns)
zchild, err = deriv(refs, zchild, tree)
if err != nil {
return nil, err
}
childPatterns = unzip(zchild, zi)
tree.Up()
}
resPatterns = derivReturns(refs, resPatterns, childPatterns)
resPatterns = simps(refs, resPatterns)
}
return resPatterns, nil
}
func deriv(mem *Mem, patterns int, tree parser.Interface) (int, error) {
for {
if !mem.escapable(patterns) {
return patterns, nil
}
if err := tree.Next(); err != nil {
if err == io.EOF {
break
} else {
return 0, err
}
}
callTree, err := mem.getCallTree(patterns)
if err != nil {
return 0, err
}
childPatterns, stackElm, err := callTree.Eval(tree)
if err != nil {
return 0, err
}
if !tree.IsLeaf() {
tree.Down()
childPatterns, err = deriv(mem, childPatterns, tree)
if err != nil {
return 0, err
}
tree.Up()
}
nullIndex := mem.getNullable(childPatterns)
patterns = mem.getReturn(stackElm, nullIndex)
}
return patterns, nil
}
func (this *msg) encode(buf []byte, offset int, p parser.Interface) ([]byte, int, error) {
for {
if err := p.Next(); err != nil {
if err == io.EOF {
return buf, offset, nil
} else {
return nil, 0, err
}
}
name, err := p.String()
if err != nil {
return nil, 0, err
}
fieldEnc, ok := this.fieldEncoders[name]
if !ok {
continue //skip field
}
p.Down()
buf, offset, err = fieldEnc.encode(buf, offset, p)
if err != nil {
return nil, 0, err
}
p.Up()
}
}
func newList(p parser.Interface, typ reflect.Type) (reflect.Value, error) {
list := reflect.MakeSlice(typ, 0, 0)
for {
if err := p.Next(); err != nil {
if err == io.EOF {
return list, nil
} else {
panic(err)
}
}
if p.IsLeaf() {
return reflect.ValueOf(nil), fmt.Errorf("list: did not expect leaf")
}
_, err := p.Int()
if err != nil {
return reflect.ValueOf(nil), err
}
elemType := typ.Elem()
elemKind := elemType.Kind()
elemIsPtr := false
if elemKind == reflect.Ptr {
elemIsPtr = true
elemType = typ.Elem().Elem()
elemKind = elemType.Kind()
}
p.Down()
switch elemKind {
case reflect.Struct:
if !p.IsLeaf() {
elem := reflect.New(elemType).Elem()
if err := encodeStruct(p, elem); err != nil {
return reflect.ValueOf(nil), err
}
if elemIsPtr {
elem = elem.Addr()
}
list = reflect.Append(list, elem)
} else {
list = reflect.Append(list, reflect.Zero(typ.Elem()))
}
case reflect.Slice:
newList, err := newList(p, elemType)
if err != nil {
return reflect.ValueOf(nil), err
}
list = reflect.Append(list, newList)
default:
elem, err := newValue(p, typ.Elem())
if err != nil {
return reflect.ValueOf(nil), err
}
list = reflect.Append(list, elem)
}
p.Up()
}
}
func (this *repeatedField) encode(buf []byte, offset int, p parser.Interface) ([]byte, int, error) {
for {
if err := p.Next(); err != nil {
if err == io.EOF {
return buf, offset, nil
} else {
return nil, 0, err
}
}
_, err := p.Int()
if err != nil {
return nil, 0, err
}
p.Down()
buf, offset, err = this.fieldEnc.encode(buf, offset, p)
if err != nil {
return nil, 0, err
}
p.Up()
}
}
//Walk walks through the whole parser in a top down manner and records the values into a Nodes structute.
func Walk(p parser.Interface) Nodes {
a := make(Nodes, 0)
for {
if err := p.Next(); err != nil {
if err == io.EOF {
break
} else {
panic(err)
}
}
value := getValue(p)
if p.IsLeaf() {
a = append(a, Node{fmt.Sprintf("%v", value), nil})
} else {
name := fmt.Sprintf("%v", value)
p.Down()
v := Walk(p)
p.Up()
a = append(a, Node{name, v})
}
}
return a
}
func encodeStruct(p parser.Interface, v reflect.Value) error {
kind := v.Type().Kind()
isPtr := false
if kind == reflect.Ptr {
kind = v.Type().Elem().Kind()
isPtr = true
}
if kind != reflect.Struct {
return fmt.Errorf("expected struct")
}
for {
if err := p.Next(); err != nil {
if err == io.EOF {
return nil
} else {
panic(err)
}
}
if p.IsLeaf() {
return fmt.Errorf("struct: did not expect leaf")
}
name, err := p.String()
if err != nil {
return err
}
strct := v
if isPtr {
strct = v.Elem()
}
field := strct.FieldByName(name)
if !field.IsValid() {
continue //skip field
}
fieldKind := field.Kind()
fieldIsPtr := false
fieldType := field.Type()
if fieldKind == reflect.Ptr {
fieldIsPtr = true
fieldKind = field.Type().Elem().Kind()
fieldType = field.Type().Elem()
}
p.Down()
switch fieldKind {
case reflect.Struct:
if !p.IsLeaf() {
if fieldIsPtr {
field.Set(reflect.New(field.Type().Elem()))
}
if err := encodeStruct(p, field); err != nil {
return err
}
}
case reflect.Slice:
list, err := newList(p, fieldType)
if err != nil {
return err
}
field.Set(list)
default:
value, err := newValue(p, fieldType)
if err != nil {
return err
}
field.Set(value)
}
p.Up()
}
}