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pry--pry/lib/pry/method.rb
2011-10-15 22:29:34 -07:00

404 lines
14 KiB
Ruby

class Pry
class Method
include RbxMethod if Helpers::BaseHelpers.rbx?
class << self
# Given a string representing a method name and optionally a binding to
# search in, find and return the requested method wrapped in a `Pry::Method`
# instance.
#
# @param [String, nil] name The name of the method to retrieve, or `nil` to
# delegate to `from_binding` instead.
# @param [Binding] target The context in which to search for the method.
# @param [Hash] options
# @option options [Boolean] :instance Look for an instance method if `name` doesn't
# contain any context.
# @option options [Boolean] :methods Look for a bound/singleton method if `name` doesn't
# contain any context.
# @return [Pry::Method, nil] A `Pry::Method` instance containing the requested
# method, or `nil` if no method could be located matching the parameters.
def from_str(name, target=TOPLEVEL_BINDING, options={})
if name.nil?
from_binding(target)
elsif name.to_s =~ /(.+)\#(\S+)\Z/
context, meth_name = $1, $2
from_module(target.eval(context), meth_name)
elsif name.to_s =~ /(.+)\.(\S+)\Z/
context, meth_name = $1, $2
from_obj(target.eval(context), meth_name)
elsif options[:instance]
from_module(target.eval("self"), name)
elsif options[:methods]
from_obj(target.eval("self"), name)
else
from_str(name, target, :instance => true) or
from_str(name, target, :methods => true)
end
end
# Given a `Binding`, try to extract the `::Method` it originated from and
# use it to instantiate a `Pry::Method`. Return `nil` if this isn't
# possible.
#
# @param [Binding] b
# @return [Pry::Method, nil]
#
def from_binding(b)
meth_name = b.eval('__method__')
if [:__script__, nil, :__binding__, :__binding_impl__].include?(meth_name)
nil
else
new(b.eval("method(:#{meth_name})"))
end
end
# Given a `Class` or `Module` and the name of a method, try to
# instantiate a `Pry::Method` containing the instance method of
# that name. Return `nil` if no such method exists.
#
# @param [Class, Module] klass
# @param [String] name
# @return [Pry::Method, nil]
def from_class(klass, name)
new(klass.instance_method(name)) rescue nil
end
alias from_module from_class
# Given an object and the name of a method, try to instantiate
# a `Pry::Method` containing the method of that name bound to
# that object. Return `nil` if no such method exists.
#
# @param [Object] obj
# @param [String] name
# @return [Pry::Method, nil]
def from_obj(obj, name)
new(obj.method(name)) rescue nil
end
# Get all of the instance methods of a `Class` or `Module`
# @param [Class,Module] klass
# @return [Array[Pry::Method]]
def all_from_class(klass)
all_from_common(klass, :instance_method)
end
# Get all of the methods on an `Object`
# @param [Object] obj
# @return [Array[Pry::Method]]
def all_from_obj(obj)
all_from_common(obj, :method)
end
# Get every `Class` and `Module`, in order, that will be checked when looking
# for an instance method to call on this object.
# @param [Object] obj
# @return [Array[Class, Module]]
def resolution_order(obj)
if obj.is_a?(Class)
singleton_class_resolution_order(obj) + instance_resolution_order(Class)
else
klass = singleton_class(obj) rescue obj.class
instance_resolution_order(klass)
end
end
# Get every `Class` and `Module`, in order, that will be checked when looking
# for methods on instances of the given `Class` or `Module`.
# This does not treat singleton classes of classes specially.
# @param [Class, Module] klass
# @return [Array[Class, Module]]
def instance_resolution_order(klass)
# include klass in case it is a singleton class,
([klass] + klass.ancestors).uniq
end
private
# See all_from_class and all_from_obj.
# If method_type is :instance_method, obj must be a `Class` or a `Module`
# If method_type is :method, obj can be any `Object`
#
# N.B. we pre-cache the visibility here to avoid O(N²) behaviour in "ls".
def all_from_common(obj, method_type)
%w(public protected private).map do |visibility|
obj.__send__(:"#{visibility}_#{method_type}s").map do |method_name|
new(obj.__send__(method_type, method_name), :visibility => visibility.to_sym)
end
end.flatten(1)
end
# Get the singleton classes of superclasses that could define methods on
# the given class object, and any modules they include.
# If a module is included at multiple points in the ancestry, only
# the lowest copy will be returned.
def singleton_class_resolution_order(klass)
resolution_order = klass.ancestors.map do |anc|
[singleton_class(anc)] + singleton_class(anc).included_modules if anc.is_a?(Class)
end.compact.flatten(1)
resolution_order.reverse.uniq.reverse - Class.included_modules
end
def singleton_class(obj); class << obj; self; end end
end
# A new instance of `Pry::Method` wrapping the given `::Method`, `UnboundMethod`, or `Proc`.
#
# @param [::Method, UnboundMethod, Proc] method
# @param [Hash] known_info, can be used to pre-cache expensive to compute stuff.
# @return [Pry::Method]
def initialize(method, known_info={})
@method = method
@visibility = known_info[:visibility]
end
# Get the name of the method as a String, regardless of the underlying Method#name type.
# @return [String]
def name
@method.name.to_s
end
# @return [String, nil] The source code of the method, or `nil` if it's unavailable.
def source
@source ||= case source_type
when :c
info = pry_doc_info
if info and info.source
code = strip_comments_from_c_code(info.source)
end
when :rbx
strip_leading_whitespace(core_code)
when :ruby
if pry_method?
code = Pry.new(:input => StringIO.new(Pry.line_buffer[source_line..-1].join), :prompt => proc {""}, :hooks => {}).r
else
code = @method.source
end
strip_leading_whitespace(code)
end
end
# @return [String, nil] The documentation for the method, or `nil` if it's
# unavailable.
# @raise [CommandError] Raises when the method was defined in the REPL.
def doc
@doc ||= case source_type
when :c
info = pry_doc_info
info.docstring if info
when :rbx
strip_leading_hash_and_whitespace_from_ruby_comments(core_doc)
when :ruby
if pry_method?
raise CommandError, "Can't view doc for a REPL-defined method."
else
strip_leading_hash_and_whitespace_from_ruby_comments(@method.comment)
end
end
end
# @return [Symbol] The source type of the method. The options are
# `:ruby` for ordinary Ruby methods, `:c` for methods written in
# C, or `:rbx` for Rubinius core methods written in Ruby.
def source_type
if Helpers::BaseHelpers.rbx?
if core? then :rbx else :ruby end
else
if source_location.nil? then :c else :ruby end
end
end
# @return [String, nil] The name of the file the method is defined in, or
# `nil` if the filename is unavailable.
def source_file
if source_location.nil?
if !Helpers::BaseHelpers.rbx? and source_type == :c
info = pry_doc_info
info.file if info
end
else
source_location.first
end
end
# @return [Fixnum, nil] The line of code in `source_file` which begins
# the method's definition, or `nil` if that information is unavailable.
def source_line
source_location.nil? ? nil : source_location.last
end
# @return [Symbol] The visibility of the method. May be `:public`,
# `:protected`, or `:private`.
def visibility
@visibility ||= if owner.public_instance_methods.include?(name)
:public
elsif owner.protected_instance_methods.include?(name)
:protected
elsif owner.private_instance_methods.include?(name)
:private
else
:none
end
end
# @return [String] A representation of the method's signature, including its
# name and parameters. Optional and "rest" parameters are marked with `*`
# and block parameters with `&`. If the parameter names are unavailable,
# they're given numbered names instead.
# Paraphrased from `awesome_print` gem.
def signature
if respond_to?(:parameters)
args = parameters.inject([]) do |arr, (type, name)|
name ||= (type == :block ? 'block' : "arg#{arr.size + 1}")
arr << case type
when :req then name.to_s
when :opt, :rest then "*#{name}"
when :block then "&#{name}"
else '?'
end
end
else
args = (1..arity.abs).map { |i| "arg#{i}" }
args[-1] = "*#{args[-1]}" if arity < 0
end
"#{name}(#{args.join(', ')})"
end
# @return [Pry::Method, nil] The wrapped method that is called when you
# use "super" in the body of this method.
def super(times=1)
if respond_to?(:receiver)
sup = super_using_ancestors(Pry::Method.resolution_order(receiver), times)
sup &&= sup.bind(receiver)
else
sup = super_using_ancestors(Pry::Method.instance_resolution_order(owner), times)
end
Pry::Method.new(sup) if sup
end
# @return [Symbol, nil] The original name the method was defined under,
# before any aliasing, or `nil` if it can't be determined.
def original_name
return nil if source_type != :ruby
first_line = source.lines.first
return nil if first_line.strip !~ /^def /
if RUBY_VERSION =~ /^1\.9/ && RUBY_ENGINE == "ruby"
require 'ripper'
# Ripper is ok with an extraneous end, so we don't need to worry about
# whether it's a one-liner.
tree = Ripper::SexpBuilder.new(first_line + ";end").parse
name = tree.flatten(2).each do |lst|
break lst[1] if lst[0] == :@ident
end
name.is_a?(String) ? name : nil
else
require 'ruby_parser'
# RubyParser breaks if there's an extra end, so we'll just rescue
# and try again.
tree = begin
RubyParser.new.parse(first_line + ";end")
rescue Racc::ParseError
RubyParser.new.parse(first_line)
end
name = tree.each_cons(2) do |a, b|
break a if b.is_a?(Array) && b.first == :args
end
name.is_a?(Symbol) ? name.to_s : nil
end
end
# @return [Boolean] Was the method defined outside a source file?
def dynamically_defined?
!!(source_file and source_file =~ /(\(.*\))|<.*>/)
end
# @return [Boolean] Was the method defined within the Pry REPL?
def pry_method?
source_file == Pry.eval_path
end
# @return [Boolean] Is the method definitely an alias?
def alias?
name != original_name
end
# @return [Boolean]
def ==(obj)
if obj.is_a? Pry::Method
super
else
@method == obj
end
end
# @param [Class] klass
# @return [Boolean]
def is_a?(klass)
klass == Pry::Method or @method.is_a?(klass)
end
alias kind_of? is_a?
# @param [String, Symbol] method_name
# @return [Boolean]
def respond_to?(method_name)
super or @method.respond_to?(method_name)
end
# Delegate any unknown calls to the wrapped method.
def method_missing(method_name, *args, &block)
@method.send(method_name, *args, &block)
end
private
# @return [YARD::CodeObjects::MethodObject]
# @raise [CommandError] Raises when the method can't be found or `pry-doc` isn't installed.
def pry_doc_info
if Pry.config.has_pry_doc
Pry::MethodInfo.info_for(@method) or raise CommandError, "Cannot find C method: #{name}."
else
raise CommandError, "Cannot locate this method: #{name}. Try `gem install pry-doc` to get access to Ruby Core documentation."
end
end
# @param [String] code
# @return [String]
def strip_comments_from_c_code(code)
code.sub(/\A\s*\/\*.*?\*\/\s*/m, '')
end
# @param [String] comment
# @return [String]
def strip_leading_hash_and_whitespace_from_ruby_comments(comment)
comment = comment.dup
comment.gsub!(/\A\#+?$/, '')
comment.gsub!(/^\s*#/, '')
strip_leading_whitespace(comment)
end
# @param [String] text
# @return [String]
def strip_leading_whitespace(text)
Pry::Helpers::CommandHelpers.unindent(text)
end
# @param [Class,Module] the ancestors to investigate
# @return [Method] the unwrapped super-method
def super_using_ancestors(ancestors, times=1)
next_owner = self.owner
times.times do
next_owner = ancestors[ancestors.index(next_owner) + 1]
return nil unless next_owner
end
next_owner.instance_method(name) rescue nil
end
end
end