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rubyrequire

Ruby: 'require' returns false even though file not loaded


I have this code:

puts require './item'
puts $"

class Light < Item
  #code
end

Item class in item.rb:

require './v3d'
require './ray'

class Item
  attr_accessor :pos 

  def initialize(pos)
    @pos = pos
  end

  def check(pos, dir)
    return nil
  end

  def normal(ray)
    return nil
  end
end

that when I run my program prints this output:

false
enumerator.so
thread.rb
rational.so
complex.so
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/enc/encdb.so
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/enc/trans/transdb.so
/usr/lib/ruby/2.3.0/unicode_normalize.rb
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/rbconfig.rb
/usr/lib/ruby/2.3.0/rubygems/compatibility.rb
/usr/lib/ruby/2.3.0/rubygems/defaults.rb
/usr/lib/ruby/2.3.0/rubygems/deprecate.rb
/usr/lib/ruby/2.3.0/rubygems/errors.rb
/usr/lib/ruby/2.3.0/rubygems/version.rb
/usr/lib/ruby/2.3.0/rubygems/requirement.rb
/usr/lib/ruby/2.3.0/rubygems/platform.rb
/usr/lib/ruby/2.3.0/rubygems/basic_specification.rb
/usr/lib/ruby/2.3.0/rubygems/stub_specification.rb
/usr/lib/ruby/2.3.0/rubygems/util/list.rb
/usr/lib/x86_64-linux-gnu/ruby/2.3.0/stringio.so
/usr/lib/ruby/2.3.0/rubygems/specification.rb
/usr/lib/ruby/2.3.0/rubygems/exceptions.rb
/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb
/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_gem.rb
/usr/lib/ruby/2.3.0/monitor.rb
/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb
/usr/lib/ruby/2.3.0/rubygems.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/version.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/core_ext/name_error.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/levenshtein.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/jaro_winkler.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkable.rb
/usr/lib/ruby/2.3.0/delegate.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers/class_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers/variable_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/name_error_checkers.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/method_name_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/spell_checkers/null_checker.rb
/usr/lib/ruby/vendor_ruby/did_you_mean/formatter.rb
/usr/lib/ruby/vendor_ruby/did_you_mean.rb
/home/<user>/Documents/ruby/ray/write_ppm.rb
/home/<user>/Documents/ruby/ray/v3d.rb
/home/<user>/Documents/ruby/ray/pixel.rb
/home/<user>/Documents/ruby/ray/image.rb
/home/<user>/Documents/ruby/ray/material.rb

then throws:

/home/<user>/Documents/ruby/ray/light.rb:4:in `<top (required)>': uninitialized constant Item (NameError)

When require './item' is called, there is no error AND it returns false. From my understanding of how require works, it seems that the program incorrectly thinks it does not need to load item.rb. Why does this happen and how can I fix it?

Edit: expanded on some code


Solution

  • I solved the problem by totally rewriting my require statements for every file. What I think the problem was, was this:

    • item.rb contained require './ray'
    • ray.rb contained require './light'
    • light.rb contained require './item' and class Light < Item

    While loading item.rb, the interpreter saw it needed to also load ray.rb and therefore light.rb. When it reached the require './item' inside light.rb, it returned false because it was in the process of loading that file. However, since it was not yet finished loading, it did not show up in $". The interpreter then needed access to the definition of the Item class to finish loading light.rb, but because it needed to finish loading light.rb to load item.rb, the interpreter thew a NameError.