# XML [![API reference](https://img.shields.io/badge/godoc-reference-5272B4)](https://pkg.go.dev/github.com/tdewolff/parse/v2/xml?tab=doc)
This package is an XML lexer written in [Go][1]. It follows the specification at [Extensible Markup Language (XML) 1.0 (Fifth Edition)](http://www.w3.org/TR/REC-xml/). The lexer takes an io.Reader and converts it into tokens until the EOF.
## Installation
Run the following command
go get -u github.com/tdewolff/parse/v2/xml
or add the following import and run project with `go get`
import "github.com/tdewolff/parse/v2/xml"
## Lexer
### Usage
The following initializes a new Lexer with io.Reader `r`:
``` go
l := xml.NewLexer(parse.NewInput(r))
```
To tokenize until EOF an error, use:
``` go
for {
tt, data := l.Next()
switch tt {
case xml.ErrorToken:
// error or EOF set in l.Err()
return
case xml.StartTagToken:
// ...
for {
ttAttr, dataAttr := l.Next()
if ttAttr != xml.AttributeToken {
// handle StartTagCloseToken/StartTagCloseVoidToken/StartTagClosePIToken
break
}
// ...
}
case xml.EndTagToken:
// ...
}
}
```
All tokens:
``` go
ErrorToken TokenType = iota // extra token when errors occur
CommentToken
CDATAToken
StartTagToken
StartTagCloseToken
StartTagCloseVoidToken
StartTagClosePIToken
EndTagToken
AttributeToken
TextToken
```
### Examples
``` go
package main
import (
"os"
"github.com/tdewolff/parse/v2/xml"
)
// Tokenize XML from stdin.
func main() {
l := xml.NewLexer(parse.NewInput(os.Stdin))
for {
tt, data := l.Next()
switch tt {
case xml.ErrorToken:
if l.Err() != io.EOF {
fmt.Println("Error on line", l.Line(), ":", l.Err())
}
return
case xml.StartTagToken:
fmt.Println("Tag", string(data))
for {
ttAttr, dataAttr := l.Next()
if ttAttr != xml.AttributeToken {
break
}
key := dataAttr
val := l.AttrVal()
fmt.Println("Attribute", string(key), "=", string(val))
}
// ...
}
}
}
```
## License
Released under the [MIT license](https://github.com/tdewolff/parse/blob/master/LICENSE.md).
[1]: http://golang.org/ "Go Language"