xpointer

The xpointer package evaluates XPointer fragment identifiers against helium documents.

Import path: github.com/lestrrat-go/helium/xpointer

package examples_test

import (
  "context"
  "fmt"

  "github.com/lestrrat-go/helium"
  "github.com/lestrrat-go/helium/xpointer"
)

func Example_xpointer_evaluate() {
  doc, err := helium.NewParser().Parse(context.Background(), []byte(`<doc><chapter><section>first</section></chapter><chapter><section>second</section></chapter></doc>`))
  if err != nil {
    fmt.Printf("failed to parse: %s\n", err)
    return
  }

  // XPointer's element() scheme navigates the document tree by child position.
  // The path "/1/2/1" means:
  //   /1 → first child element of the document → <doc>
  //   /2 → second child of <doc>               → <chapter> (the second one)
  //   /1 → first child of that <chapter>        → <section>
  //
  // Child indices in element() are 1-based and only count element nodes
  // (text nodes, comments, etc. are skipped).
  nodes, err := xpointer.Evaluate(context.Background(), doc, "element(/1/2/1)")
  if err != nil {
    fmt.Printf("xpointer error: %s\n", err)
    return
  }

  for _, n := range nodes {
    fmt.Printf("%s: %s\n", n.Name(), string(n.Content()))
  }
  // Output:
  // section: second
}

source: examples/xpointer_evaluate_example_test.go