Class: ExecEnv::Env

Inherits:
Object
  • Object
show all
Defined in:
lib/exec_env/env.rb

Overview

A manipulatable execution environment, that let’s you inject local and instance variables into a block and capture messages sent during it’s execution.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(locals: {}, ivars: {}, scope: nil) ⇒ Env

Returns a new instance of Env.



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# File 'lib/exec_env/env.rb', line 45

def initialize (locals: {}, ivars: {}, scope: nil)
  @messages = []
  @locals = locals
  @ivars = ivars
  @scope = scope
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, &block) ⇒ Object 



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# File 'lib/exec_env/env.rb', line 77

def method_missing (name, *args, &block)
  if @locals.key?(name) && args.size == 0 && !block
    @locals[name]
  elsif @scope && @scope.respond_to?(name)
    @scope.send(name, *args, &block)
  else
    @messages << [name, args, block]

    nil
  end
end

Instance Attribute Details

#ivars ⇒ Object

A hash of instance variables, that will be injected into the block

Examples

env.ivars = { :@foo => 3, :@bar => :symbol }



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# File 'lib/exec_env/env.rb', line 18

def ivars
  @ivars
end

#locals ⇒ Object

A hash of local variables, that will be injected into the block

Examples

env.locals = { foo: 3, bar: :symbol }



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# File 'lib/exec_env/env.rb', line 11

def locals
  @locals
end

#messages ⇒ Object (readonly)

An array of all messages that were not captured by locals or the scope object.

Examples

env.exec do
  test :foo, "bar"
  each do
    # ...
  end
end

env.messages
# => [[:test, [:foo, "bar], nil], [:each, [], <the block>]]



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# File 'lib/exec_env/env.rb', line 43

def messages
  @messages
end

#scope ⇒ Object

An object, that will serve as the scope of execution of the block

Examples

# Unresolved method calls in the block will be forwarded to
# the String object "An object"
env.scope = "An object"



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# File 'lib/exec_env/env.rb', line 27

def scope
  @scope
end

Instance Method Details

#exec(*args, &block) ⇒ Object

Execute a block in the manipulated environment.

Additional arguments will be passed to the block.

Returns the return value of the block



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# File 'lib/exec_env/env.rb', line 57

def exec (*args, &block)
  if @scope
    @scope.instance_variables.each do |name|
      instance_variable_set(name, @scope.instance_variable_get(name))
    end
  end

  @ivars.each do |name, value|
    instance_variable_set(name, value)
  end
  
  instance_exec(*args, &block)
end

#xsend(name, *args, &block) ⇒ Object

Send a message, that completely bypasses the locals and the scope and is added directly to #messages.



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# File 'lib/exec_env/env.rb', line 73

def xsend (name, *args, &block)
  @messages << [name, args, block]
end