LibYAML2.jl

A Julia wrapper for libyaml, providing fast and minimal YAML parsing.

Why LibYAML2.jl?

LibYAML.jl was unmaintained at the time LibYAML2.jl was created.

Installation

To install LibYAML2, simply use the Julia package manager:

] add LibYAML2

Usage

A basic example of parsing structured YAML data in Julia, including anchors and merge keys:

using LibYAML2

yaml_config = """
defaults: &defaults
  port: !!int 443
  enable_tls: true

server:
  <<: *defaults
  bind_address: "0.0.0.0"
  tls:
    cert_file: "/etc/certs/cert_file.pem"
    key_file: "/etc/certs/key_file.pem"

metrics:
  prometheus_enabled: true
  listen: "0.0.0.0:9100"
  service_labels: {service: "secure-backend"}

role_defaults: &role_defaults
  permissions:
    - read
    - write

users:
  - username: "admin"
    <<: *role_defaults
  - username: "stanislav"
    <<: *role_defaults
    permissions:
      - read
"""

julia> parse_yaml(yaml_config)
Dict{String, Any} with 5 entries:
  "metrics" => Dict{String,Any}("listen"=>"0.0.0.0:9100", …)
  "users"   => Any[...]
  ...

Comparison of `YAML.jl` and `LibYAML2.jl`

Feature	`YAML.jl`	`LibYAML2.jl`
Implicit type parsing	Always	Only when explicitly specified
YAML emission (serialization) support	✅	❌
`!include` support	❌	✅
Newline handling in quoted strings	❌ Broken	✅ Correct
Multiple top-level documents (`---`)	❌ (`load_all_file` broken)	✅
YAML 1.2 compliance	Limited	Full (via `libyaml`)
Pure Julia implementation	✅	❌ (uses `libyaml`)
Performance	Low	High

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