Class: Pry::CodeObject

Inherits:
Object show all
Includes:
Helpers::CommandHelpers
Defined in:
lib/pry/code_object.rb

Overview

This class is responsible for taking a string (identifying a command/class/method/etc) and returning the relevant type of object. For example, if the user looks up "show-source" then a Pry::Command will be returned. Alternatively, if the user passes in "Pry#repl" then a Pry::Method object will be returned.

The CodeObject.lookup method is responsible for 1. figuring out what kind of object the user wants (applying precedence rules in doing so -- i.e methods get precedence over commands with the same name) and 2. Returning the appropriate object. If the user fails to provide a string identifer for the object (i.e they pass in nil or "") then the object looked up will be the 'current method' or 'current class' associated with the Binding.

TODO: This class is a clusterfuck. We need a much more robust concept of what a "Code Object" really is. Currently commands/classes/candidates/methods and so on just share a very ill-defined interface.

Defined Under Namespace

Modules: Helpers

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Helpers::CommandHelpers

#absolute_index_number, #absolute_index_range, #get_method_or_raise, #internal_binding?, #one_index_number, #one_index_range, #one_index_range_or_number, #restrict_to_lines, #set_file_and_dir_locals, #temp_file, #unindent

Methods included from Helpers::OptionsHelpers

method_object, #method_object, method_options, #method_options

Constructor Details

#initialize(str, pry_instance, options = {}) ⇒ CodeObject

Returns a new instance of CodeObject


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# File 'lib/pry/code_object.rb', line 82

def initialize(str, pry_instance, options = {})
  options = {
    super: 0
  }.merge!(options)

  @str = str
  @pry_instance = pry_instance
  @target = pry_instance.current_context
  @super_level = options[:super]
end

Instance Attribute Details

#pry_instanceObject

Returns the value of attribute pry_instance


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# File 'lib/pry/code_object.rb', line 79

def pry_instance
  @pry_instance
end

#strObject

Returns the value of attribute str


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# File 'lib/pry/code_object.rb', line 77

def str
  @str
end

#super_levelObject

Returns the value of attribute super_level


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# File 'lib/pry/code_object.rb', line 80

def super_level
  @super_level
end

#targetObject

Returns the value of attribute target


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# File 'lib/pry/code_object.rb', line 78

def target
  @target
end

Class Method Details

.lookup(str, pry_instance, options = {}) ⇒ Object


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# File 'lib/pry/code_object.rb', line 69

def lookup(str, pry_instance, options = {})
  co = new(str, pry_instance, options)

  co.default_lookup || co.method_or_class_lookup ||
    co.command_lookup || co.empty_lookup
end

Instance Method Details

#command_lookupObject

TODO: just make it so find_command_by_match_or_listing doesn't raise?


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# File 'lib/pry/code_object.rb', line 94

def command_lookup
  pry_instance.commands.find_command_by_match_or_listing(str)
rescue StandardError
  nil
end

#default_lookupObject

lookup variables and constants and self that are not modules


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# File 'lib/pry/code_object.rb', line 118

def default_lookup
  # we skip instance methods as we want those to fall through to
  # method_or_class_lookup()
  if safe_to_evaluate?(str) && !looks_like_an_instance_method?(str)
    obj = target.eval(str)

    # restrict to only objects we KNOW for sure support the full API
    # Do NOT support just any object that responds to source_location
    if sourcable_object?(obj)
      Pry::Method(obj)
    elsif !obj.is_a?(Module)
      Pry::WrappedModule(obj.class)
    end
  end
rescue Pry::RescuableException
  nil
end

#empty_lookupObject

when no paramter is given (i.e CodeObject.lookup(nil)), then we lookup the 'current object' from the binding.


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# File 'lib/pry/code_object.rb', line 102

def empty_lookup
  return nil if str && !str.empty?

  obj = if internal_binding?(target)
          mod = target_self.is_a?(Module) ? target_self : target_self.class
          Pry::WrappedModule(mod)
        else
          Pry::Method.from_binding(target)
        end

  # respect the super level (i.e user might have specified a
  # --super flag to show-source)
  lookup_super(obj, super_level)
end

#looks_like_an_instance_method?(str) ⇒ Boolean (private)

Returns true if str looks like a method, i.e Klass#method We need to consider this case because method lookups should fall through to the method_or_class_lookup() method but a defined?() on a "Klass#methodstring will see the#as a comment and only evaluate theKlass` part.

Parameters:

  • str (String)

Returns:

  • (Boolean)

    Whether the string looks like an instance method.


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# File 'lib/pry/code_object.rb', line 163

def looks_like_an_instance_method?(str)
  str =~ /\S#\S/
end

#lookup_super(obj, super_level) ⇒ Object (private)

grab the nth (super_level) super of `obj

Parameters:

  • obj (Object)
  • super_level (Fixnum)

    How far up the super chain to ascend.

Raises:


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# File 'lib/pry/code_object.rb', line 188

def lookup_super(obj, super_level)
  return unless obj

  sup = obj.super(super_level)
  raise Pry::CommandError, "No superclass found for #{obj.wrapped}" unless sup

  sup
end

#method_or_class_lookupObject


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# File 'lib/pry/code_object.rb', line 136

def method_or_class_lookup
  obj =
    case str
    when /\S+\(\)\z/
      Pry::Method.from_str(str.sub(/\(\)\z/, ''), target) ||
      Pry::WrappedModule.from_str(str, target)
    else
      Pry::WrappedModule.from_str(str, target) ||
      Pry::Method.from_str(str, target)
    end

  lookup_super(obj, super_level)
end

#safe_to_evaluate?(str) ⇒ Boolean (private)

We use this method to decide whether code is safe to eval. Method's are generally not, but everything else is. TODO: is just checking != "method" enough?? TODO: see duplication of this method in Pry::WrappedModule

Parameters:

  • str (String)

    The string to lookup

Returns:

  • (Boolean)

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# File 'lib/pry/code_object.rb', line 173

def safe_to_evaluate?(str)
  return true if str.strip == "self"
  return false if str =~ /%/

  kind = target.eval("defined?(#{str})")
  kind =~ /variable|constant/
end

#sourcable_object?(obj) ⇒ Boolean (private)

Returns:

  • (Boolean)

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# File 'lib/pry/code_object.rb', line 152

def sourcable_object?(obj)
  [::Proc, ::Method, ::UnboundMethod].any? { |o| obj.is_a?(o) }
end

#target_selfObject (private)


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# File 'lib/pry/code_object.rb', line 181

def target_self
  target.eval('self')
end