02-list-objects

Example 02: List Objects

Advanced file navigation and object hierarchy exploration

What This Example Demonstrates

• Detailed object traversal
• Reading group children
• Exploring nested structures
• Understanding object relationships

Quick Start

go run main.go

What You'll See

Output:

Superblock version: 2

Objects in file:
  Group: / (children: 1)
    - data
  Dataset: /data

Code Breakdown

Exploring Groups

case *hdf5.Group:
    fmt.Printf("  Group: %s (children: %d)\n",
        path, len(v.Children()))

    // List all children
    for _, child := range v.Children() {
        fmt.Printf("    - %s\n", child.Name())
    }

Identifying Datasets

case *hdf5.Dataset:
    fmt.Printf("  Dataset: %s\n", path)

Use Cases

1. Count Objects by Type

var groups, datasets int

file.Walk(func(path string, obj hdf5.Object) {
    switch obj.(type) {
    case *hdf5.Group:
        groups++
    case *hdf5.Dataset:
        datasets++
    }
})

fmt.Printf("Groups: %d, Datasets: %d\n", groups, datasets)

2. Build Object Index

index := make(map[string]hdf5.Object)

file.Walk(func(path string, obj hdf5.Object) {
    index[path] = obj
})

// Later: access any object by path
if obj, ok := index["/data"]; ok {
    fmt.Printf("Found: %s\n", obj.Name())
}

3. Find Deeply Nested Objects

file.Walk(func(path string, obj hdf5.Object) {
    depth := strings.Count(path, "/") - 1
    if depth > 3 {
        fmt.Printf("Deep object: %s (depth: %d)\n",
            path, depth)
    }
})

Next Steps

• Example 03 - Read dataset values
• Reading Data Guide - Complete guide

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Part of the HDF5 Go Library v0.10.0-beta