class Puppet::Parser::ParserFactory

The ParserFactory makes selection of parser possible. Currently, it is possible to switch between two different parsers:

::classic_parser, the parser in 3.1
eparser, the Expression Based Parser

Public Class Methods

assert_rgen_installed() click to toggle source

Asserts that RGen >= 0.6.6 is installed by checking that certain behavior is available. Note that this assert is expensive as it also requires puppet/pops (if not already loaded).

# File lib/puppet/parser/parser_factory.rb, line 43
def self.assert_rgen_installed
  @@asserted ||= false
  return if @@asserted
  @@asserted = true
  begin
    require 'rgen/metamodel_builder'
  rescue LoadError
    raise Puppet::DevError.new("The gem 'rgen' version >= 0.7.0 is required when using the setting '--parser future'. Please install 'rgen'.")
  end
  # Since RGen is optional, there is nothing specifying its version.
  # It is not installed in any controlled way, so not possible to use gems to check (it may be installed some other way).
  # Instead check that "eContainer, and eContainingFeature" has been installed.
  require 'puppet/pops'
  begin
    litstring = Puppet::Pops::Model::LiteralString.new();
    container = Puppet::Pops::Model::ArithmeticExpression.new();
    container.left_expr = litstring
    raise "no eContainer" if litstring.eContainer() != container
    raise "no eContainingFeature" if litstring.eContainingFeature() != :left_expr
  rescue => e
    # TODO: RGen can raise exceptions for other reasons!
    raise Puppet::DevError.new("The gem 'rgen' version >= 0.7.0 is required when using '--parser future'. An older version is installed, please update.")
  end
end

classic_parser(environment) click to toggle source

Creates an instance of the classic parser.

# File lib/puppet/parser/parser_factory.rb, line 21
def self.classic_parser(environment)
  # avoid expensive require if already loaded
  require 'puppet/parser' unless defined? Puppet::Parser::Parser
  Puppet::Parser::Parser.new(environment)
end

code_merger() click to toggle source

# File lib/puppet/parser/parser_factory.rb, line 68
def self.code_merger
  if Puppet.future_parser?
    Puppet::Pops::Parser::CodeMerger.new
  else
    Puppet::Parser::CodeMerger.new
  end
end

evaluating_parser(file_watcher) click to toggle source

Creates an instance of an E4ParserAdapter that adapts an EvaluatingParser to the 3x way of parsing.

# File lib/puppet/parser/parser_factory.rb, line 30
def self.evaluating_parser(file_watcher)
  # Since RGen is optional, test that it is installed
  assert_rgen_installed()
  unless defined?(Puppet::Pops::Parser::E4ParserAdapter)
    require 'puppet/parser/e4_parser_adapter'
    require 'puppet/pops/parser/code_merger'
  end
  E4ParserAdapter.new(file_watcher)
end

parser(environment) click to toggle source

Produces a parser instance for the given environment

# File lib/puppet/parser/parser_factory.rb, line 11
def self.parser(environment)
  if Puppet.future_parser?
    evaluating_parser(environment)
  else
    classic_parser(environment)
  end
end