Exercism v3 launches on Sept 1st 2021. Learn more! ๐Ÿš€๐Ÿš€๐Ÿš€
Avatar of aleksb

aleksb's solution

to Accumulate in the Raku Track

Published at Jul 06 2020 · 0 comments
Instructions
Test suite
Solution

Note:

This exercise has changed since this solution was written.

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.

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.

Restrictions

Keep your hands off that collect/map/fmap/whatchamacallit functionality provided by your standard library! Solve this one yourself using other basic tools instead.

Resources

Remember to check out the Raku documentation and resources pages for information, tips, and examples if you get stuck.

Running the tests

There is a test suite and module included with the exercise. The test suite (a file with the extension .t6) will attempt to run routines from the module (a file with the extension .pm6). Add/modify routines in the module so that the tests will pass! You can view the test data by executing the command perl6 --doc *.t6 (* being the name of the test suite), and run the test suite for the exercise by executing the command prove6 . in the exercise directory.

Source

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.

unit module Accumulate;

# OK this is overkill (below method is better)
# First the R, operator is applied to swap args
# Then map, and convert to List
our &accumulate is export = &circumfix:<[ ]> o &map o &infix:<R,>

#our sub accumulate is export {
#    return [@^a.map: $^b]
#}

Community comments

Find this solution interesting? Ask the author a question to learn more.

What can you learn from this solution?

A huge amount can be learned from reading other peopleโ€™s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

  • What compromises have been made?
  • Are there new concepts here that you could read more about to improve your understanding?