Strain in Erlang
Implement the `keep` and `discard` operation on collections. Given a collection and a predicate on the collection's elements, `keep` returns a new collection containing those elements where the predicate is true, while `discard` returns a new collection containing those elements where the predicate is false.
exercism fetch erlang strain
discard operation on collections. Given a collection
and a predicate on the collection's elements,
keep returns a new collection
containing those elements where the predicate is true, while
a new collection containing those elements where the predicate is false.
For example, given the collection of numbers:
- 1, 2, 3, 4, 5
And the predicate:
- is the number even?
Then your keep operation should produce:
- 2, 4
While your discard operation should produce:
- 1, 3, 5
Note that the union of keep and discard is all the elements.
The functions may be called
discard, or they may need different
names in order to not clash with existing functions or concepts in your
Keep your hands off that filter/reject/whatchamacallit functionality provided by your standard library! Solve this one yourself using other basic tools instead.
In order to run the tests, issue the following command from the exercise directory:
For running the tests provided,
rebar3 is used as it is the official build and
dependency management tool for erlang now. Please refer to the tracks installation
instructions on how to do that.
In order to run the tests, you can issue the following command from the exercise directory.
$ rebar3 eunit
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TEST_VERSION in the test file and
verifies that the solution defines and exports a function
returning that same value.
To make tests pass, add the following to your solution:
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