ðŸŽ‰ Exercism Research is now launched. Help Exercism, help science and have some fun at research.exercism.io ðŸŽ‰

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]
#}``````