Accumulate in Ruby
Implement the `accumulate` operation, which, given a collection and an operation to perform on each element of the collection, returns a new collection containing the result of applying that operation to each element of the input collection.
exercism fetch ruby accumulate
accumulate operation, which, given a collection and an
operation to perform on each element of the collection, returns a new
collection containing the result of applying that operation to each element of
the input collection.
Given the collection of numbers:
- 1, 2, 3, 4, 5
And the operation:
- square a number (
x => x * x)
Your code should be able to produce the collection of squares:
- 1, 4, 9, 16, 25
Check out the test suite to see the expected function signature.
Keep your hands off that collect/map/fmap/whatchamacallit functionality provided by your standard library! Solve this one yourself using other basic tools instead.
Lisp specific: it's perfectly fine to use
MAPCAR or the equivalent,
as this is idiomatic Lisp, not a library function.
It is typical to call #to_enum when defining methods for a generic Enumerable, in case no block is passed.
Here is an additional test you could add:
def test_no_block_is_passed skip result = [1, 2, 3].accumulate assert_instance_of Enumerator, result end
For installation and learning resources, refer to the exercism help page.
For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:
gem install minitest
If you would like color output, you can
require 'minitest/pride' in
the test file, or note the alternative instruction, below, for running
the test file.
In order to run the test, you can run the test file from the exercise
directory. For example, if the test suite is called
hello_world_test.rb, you can run the following command:
To include color from the command line:
ruby -r minitest/pride hello_world_test.rb
Conversation with James Edward Gray II https://twitter.com/jeg2
Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.