20 lines
1.3 KiB
Markdown
20 lines
1.3 KiB
Markdown
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# Instructions
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Implement basic list operations.
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In functional languages list operations like `length`, `map`, and `reduce` are very common.
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Implement a series of basic list operations, without using existing functions.
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The precise number and names of the operations to be implemented will be track dependent to avoid conflicts with existing names, but the general operations you will implement include:
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- `append` (*given two lists, add all items in the second list to the end of the first list*);
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- `concatenate` (*given a series of lists, combine all items in all lists into one flattened list*);
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- `filter` (*given a predicate and a list, return the list of all items for which `predicate(item)` is True*);
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- `length` (*given a list, return the total number of items within it*);
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- `map` (*given a function and a list, return the list of the results of applying `function(item)` on all items*);
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- `foldl` (*given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left*);
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- `foldr` (*given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right*);
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- `reverse` (*given a list, return a list with all the original items, but in reversed order*).
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Note, the ordering in which arguments are passed to the fold functions (`foldl`, `foldr`) is significant.
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