Parser for metadata header in plain-text files

Syntax

@key value

@key
  value line 1
  value line 2

@key

Any kind of comment syntax or prefix can be used:

/*
 * @key value
 */

An alternative syntax is also supported:

Key Name: Value

Parsing stops at the first empty line (ignoring white space).

Usage

require 'metaheader'

input = '@key value'
mh = MetaHeader.new input

# alternatively:
# mh = MetaHeader.from_file path

# mark unknown keys as invalid
# mh.strict = true

# set @key as optional
errors = mh.validate :key => MetaHeader::OPTIONAL

# or set @key as required:
# mh.validate :key => MetaHeader::REQUIRED
#
# ensure @key contains a valid value with a regex
# mh.validate :key => /^\w{2,}$/

value = mh[:key]