lib/ffi-glib/list_methods.rb
# frozen_string_literal: true
require "ffi-glib/container_class_methods"
module GLib
# Common methods for List and SList.
module ListMethods
include Enumerable
attr_reader :element_type
def self.included(base)
# Override default field accessors.
replace_method base, :next, :tail
replace_method base, :data, :head
base.extend ContainerClassMethods
base.extend ClassMethods
end
def self.replace_method(base, old, new)
base.class_eval do
remove_method old
alias_method old, new
end
end
def initialize(type)
store_pointer(FFI::Pointer.new(0))
@element_type = type
end
def each
reset_iterator
while (elem = next_element)
yield elem
end
end
def tail
return nil if struct.null?
self.class.wrap(element_type, struct[:next])
end
def head
return nil if struct.null?
GirFFI::ArgHelper.cast_from_pointer(element_type, struct[:data])
end
def reset_typespec(typespec)
@element_type = typespec
self
end
def ==(other)
to_a == other.to_a
end
private
def reset_iterator
@current = self
end
def next_element
return unless @current
element = @current.head
@current = @current.tail
element
end
def element_ptr_for(data)
GirFFI::InPointer.from(element_type, data)
end
# Common class methods for List and SList
module ClassMethods
def from_enumerable(type, arr)
arr.reduce(new(type)) { |lst, val| lst.prepend val }.reverse
end
end
end
end