Fuzion

Runtime implementation of shortcut fusion for JavaScript and TypeScript.

Definition (haskell docs)

Shortcut fusion is an optimizer method that merges some function calls into one. E.g., map f * map g can be substituted by map (f * g), and filter p * filter q can be substituted by filter (\x -> q x && p x). It can also help to remove intermediate data structures. E.g., computing sum [1..n] does not require an explicit list structure, and the expression is actually translated into a simple loop.

API

So far, it supports the following operators:

• fuzion - performs left-to-right function composition. In some libraries this function is named pipe, sequence.
• map - applies another function to a list of elements and returns a new result on every element in the calling array.
• filter - invokes a provided predicate function for each array element and includes it into the result.
• forEach - executes a provided function once for each array element.
• take - cuts the length of the produced result. It helps to save operators calls to other operators on array elements that will not be included in the final result.