Control Flow

1. Map

"Map" is the operator that helps you iterate over an object (either a list or a string), and apply a function to it.

Syntax: It is represented by the character M and it is bounded (ended) using the character }. It applies the code between M and } for each element of the object you iterate on.

Example: Let's say you have a list of integers given as input, and you want to increment each of them by 1. Then this code should do it:

..)..
.IEM.
@}...

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Details: For each element in the given object, create a separate stack containing that element only and apply the given code. Once the execution finished, it appends the top of the created stack to a list. After each element is handled, the list is appended to the main stack.

2. Filter

"Filter" is the operator that lets you remove the elements in a list that don't meet certain conditions.

Syntax: It is represented by the character F and it bounded by {. So F...{ runs ... on a separate stack for each element of the iterable you filter, and removes those that yield a falsy result.

Example: Let's say that you are given a list of numbers as input, and you want to remove those that aren't higher than 6. Then this code should work just fine for you:

..)..
.IEF.
)6<{.

Details: For each element in the given object, create a separate stack containing that element only and apply the given code. Once the execution finished, it appends the element to a list if the top of the created stack is truthy. After each element is handled, the list is appended to the main stack.

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Please note that control flow structures are not nestable.