What does list map do in OCaml?

In summary, use List. map when you’d like to see something done to each element in a list, use List. iter when you’d like to see something done with each element in a list.

What is list Rev in OCaml?

rev ( List. map f l) , but is tail-recursive and more efficient. val filter_map : (‘a -> ‘b option) -> ‘a list -> ‘b list. filter_map f l applies f to every element of l , filters out the None elements and returns the list of the arguments of the Some elements.

How do I add something to the end of a list in OCaml?

Adding an element at the end of a list requires a full copy of the list. Adding an element at the front of the list requires allocating a single cell—the tail of the new list can just point to the old list. Show activity on this post. list@[element] should work.

What is fun in OCaml?

let x = 42. val x : int = 42. Similarly, OCaml functions do not have to have names; they may be anonymous. For example, here is an anonymous function that increments its input: fun x -> x + 1 . Here, fun is a keyword indicating an anonymous function, x is the argument, and -> separates the argument from the body.

What is ref in OCaml?

ref’s (references) allow you to make any type of value mutable (sort of). More properly, ref’s are an abstraction of the concept of an “updateable location” which can be initialized to any value: like a memory cell.

What is a list in OCaml?

A list is an ordered sequence of elements. All elements of a list in OCaml must be the same type. Lists are built into the language and have a special syntax. Here is a list of three integers: # [1; 2; 3];; – : int list = [1; 2; 3] Note semicolons separate the elements, not commas.

What does list Fold_left do in OCaml?

fold_left operates on lists, as your function does, by applying a function and accumulating a result in a particular manner. It takes care of and abstracts the recursion for you.

What is Val in OCaml?

Well, val is a keyword in OCaml with several different uses. The cases you mention are both, in essence, that val is used in a module signature to specify values that appear in the module. Values are things like functions and expressions.

Are lists mutable in OCaml?

Arrays are different from List and OCaml’s lists are immutable.

What does list fold do OCaml?

fold_left operates on lists, as your function does, by applying a function and accumulating a result in a particular manner. It takes care of and abstracts the recursion for you. It deals with the structure of the list, so you can deal with how to combine the elements of the list in a particular manner.

How to use map function in OCaml?

In OCaml, we can use the map function with the list library we have already; this function is the part of the list in OCaml so that it can be called on the list. This function takes two arguments as the parameter and bit tricky to understand as well.

Can all elements of a list in OCaml be the same type?

All elements of a list in OCaml must be the same type. Lists are built into the language and have a special syntax. Here is a list of three integers: Note semicolons separate the elements, not commas.

How do I re-compile my OCaml program?

CTRL-C-CTRL-C or Meta-X compile: launches re-compilation from within the editor (using the make command). CTRL-X-` : puts the cursor in the file and at the exact place where the OCaml compiler has signaled an error.

How to find all occurrences of a certain string in OCaml?

Under Unix, the CTRL-C-CTRL-C or Meta-X compile combination, followed by CTRL-X-` is also used to find all occurrences of a certain string in a OCaml program.