Class: Teapot::Environment

Inherits:
Object
  • Object
show all
Defined in:
lib/teapot/environment/base.rb,
lib/teapot/environment/system.rb,
lib/teapot/environment/flatten.rb,
lib/teapot/environment/evaluator.rb,
lib/teapot/environment/constructor.rb

Overview

This is the basic environment data structure which is essentially a linked list of hashes. It is primarily used for organising build configurations across a wide range of different sub-systems, e.g. platform configuration, target configuration, local project configuration, etc. The majority of the actual functionality is exposed in the ‘environment/*.rb` files.

Defined Under Namespace

Modules: System Classes: Constructor, Default, Evaluator, Replace

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parent = nil, values = {}, &block) ⇒ Environment

Returns a new instance of Environment.



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# File 'lib/teapot/environment/base.rb', line 24

def initialize(parent = nil, values = {}, &block)
	@values = (values || {}).to_hash
	@parent = parent
	
	if block_given?
		Constructor.new(self).instance_exec(&block)
	end
end

Instance Attribute Details

#parent ⇒ Object (readonly)

Returns the value of attribute parent.



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# File 'lib/teapot/environment/base.rb', line 34

def parent
  @parent
end

#values ⇒ Object (readonly)

Returns the value of attribute values.



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# File 'lib/teapot/environment/base.rb', line 33

def values
  @values
end

Class Method Details

.combine(*environments) ⇒ Object 



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# File 'lib/teapot/environment/constructor.rb', line 58

def self.combine(*environments)
	# Flatten the list of environments:
	environments = environments.collect do |environment|
		if Environment === environment
			environment.to_a
		else
			environment
		end
	end.flatten
	
	# Resequence based on order:
	first = Environment.new(nil, environments.shift)
	top = first
	
	environments.each do |tail|
		top = Environment.new(top, tail)
	end
	
	return top
end

.system_environment(env = ENV) ⇒ Object

Construct an environment from a given system environment:



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# File 'lib/teapot/environment/system.rb', line 52

def self.system_environment(env = ENV)
	self.new(Hash[env.map{|key, value| [key.downcase.to_sym, value]}])
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/teapot/environment/base.rb', line 44

def [] (key)
	environment = lookup(key)
	
	environment ? environment.values[key] : nil
end

#[]=(key, value) ⇒ Object 



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# File 'lib/teapot/environment/base.rb', line 50

def []= (key, value)
	@values[key] = value
end

#flatten ⇒ Object 



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# File 'lib/teapot/environment/flatten.rb', line 23

def flatten
	hash = {}
	
	# Flatten this chain of environments:
	flatten_to_hash(hash)
	
	# Evaluate all items to their respective object value:
	evaluator = Evaluator.new(hash)
	
	# Evaluate all the individual environment values so that they are flat:
	Hash[hash.map{|key, value| [key, evaluator.object_value(value)]}]
end

#lookup(name) ⇒ Object 



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# File 'lib/teapot/environment/base.rb', line 36

def lookup(name)
	if @values.include? name
		self
	elsif @parent
		@parent.lookup(name)
	end
end

#merge(&block) ⇒ Object 



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# File 'lib/teapot/environment/constructor.rb', line 79

def merge(&block)
	self.class.combine(
		self,
		self.class.new(&block)
	)
end

#to_a ⇒ Object

Convert the hierarchy of environments to an array where the parent comes before the child.



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# File 'lib/teapot/environment/constructor.rb', line 87

def to_a
	flat = []
	
	flatten_to_array(flat)
	
	return flat
end

#to_hash ⇒ Object 



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# File 'lib/teapot/environment/base.rb', line 54

def to_hash
	@values
end

#to_s ⇒ Object 



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# File 'lib/teapot/environment/base.rb', line 58

def to_s
	"<#{self.class} #{self.values}>"
end