/
wrap.go
74 lines (68 loc) · 1.46 KB
/
wrap.go
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// Copyright 2017 Sam Whited.
// Use of this source code is governed by the BSD 2-clause
// license that can be found in the LICENSE file.
package xmlstream
import (
"encoding/xml"
"io"
)
// Wrap wraps a token stream in a start element and its corresponding end
// element.
func Wrap(r TokenReader, start xml.StartElement) TokenReader {
state := 0
return ReaderFunc(func() (t xml.Token, err error) {
switch state {
case 0:
state++
return start, nil
case 1:
t, err = r.Token()
if err == io.EOF {
state++
err = nil
}
if t == nil {
state++
t = start.End()
}
return t, err
case 2:
state++
return start.End(), io.EOF
default:
return nil, io.EOF
}
})
}
// Unwrap reads the next token from the provided TokenReader and, if it is a
// start element, returns a new TokenReader that skips the corresponding end
// element. If the token is not a start element the original TokenReader is
// returned.
func Unwrap(r TokenReader) (TokenReader, xml.Token, error) {
t, err := r.Token()
if err != nil {
return r, t, err
}
start, ok := t.(xml.StartElement)
if !ok {
return r, t, err
}
depth := 0
return ReaderFunc(func() (t xml.Token, err error) {
t, err = r.Token()
switch tok := t.(type) {
case xml.StartElement:
if tok.Name == start.Name {
depth++
}
case xml.EndElement:
if tok.Name == start.Name {
depth--
if depth == -1 {
t, err = r.Token()
}
}
}
return t, err
}), t, err
}