Iterates through documents in a stream

YAML::load_documents(
  (String or IO) io,
  Proc doc_proc
)

A Ruby object

The YAML::load_documents method is great for parsing streaming data, especially data which has a fixed formatting. For example, let's suppose you are reading from a log file:

---
at: 2001-08-12 09:25:00.00 Z
type: GET
HTTP: '1.0'
url: '/index.html'
---
at: 2001-08-12 09:25:10.00 Z
type: GET
HTTP: '1.0'
url: '/toc.html'

Ex. 39: Stream containing a log file

Using YAML::load_documents, you can process each entry individually, without needing to allocate space for the entire file contents in memory. With each iteration, the current document is passed into the Proc you supply:

require 'yaml'
log = File.open( "/var/log/apache.yaml" )
yp = YAML::load_documents( log ) { |doc|
  puts "#{doc['at']} #{doc['type']} #{doc['url']}"
}

Ex. 40: Loading the log file with YAML::load_documents

The IO object is closed upon completion of parsing.