What is <> in OCaml?
What is <> in OCaml?
OCaml distinguishes between structural equality and physical equality (essentially equality of the address of an object). = is structural equality and == is physical equality. Beware: <> is structural not-equals while != is physical not-equals.
How do I start OCaml?
Starting OCaml
- In a terminal window, type utop to start the interactive OCaml session, commonly called the toplevel.
- Press Control-D to exit the toplevel. You can also enter #quit;; and press return. Note that you must type the # there: it is in addition to the # prompt you already see.
How do you comment on OCaml?
Comments in OCaml must contain legal OCaml lexical units (tokens). This allows you to comment out code easily, even code with comments. Even code with string constants that happen to contain (* or *) . You can have “\\” in a comment.
What is assert in OCaml?
The built-in assert takes an expression as an argument and throws an exception if the provided expression evaluates to false .
What is ref in OCaml?
There are only two built-in mutable data structures in OCaml: refs and arrays. OCaml supports imperative programming through the primitive parameterized ref type. A ref is the simplest mutable data structure. A mutable data structure is one that be changed imperatively, or mutated.
How do I run OCaml test?
How does in work in OCaml?
Implicit vs. (In the “translated from the French” language of OCaml error messages this means “you put a float here, but I was expecting an int”). To add two floats together you need to use a different operator, +.
What is null in Ocaml?
@JeffMercado: null is a common name in FP for the function that tests whether a list is empty or not.
What is some in Ocaml?
Some is a constructor of the option type. The definition is roughly: type ‘a option = Some of ‘a | None. Which means that it either holds a value of some unspecified ( ‘a ) type ( Some ) or it is empty ( None ). So Some 10 is an int option , the Some true is a bool option and the Some “ok” is a string option .
How does OCaml print the type of an expression?
When we type our expressions into the OCaml top level, OCaml prints the type: – : char = ‘c’ # “Help me!”;; – : string = “Help me!” Each expression has one and only one type. OCaml works out types automatically so you will rarely need to explicitly write down the type of your functions.
What is the OCaml command used for?
The ocaml command provides a basic top level (you should install rlwrap through your system package manager and run rlwrap ocaml instead to get history navigation.) The alternative REPL utop may be installed through opam or your system package manager.
Where can I download the OCaml editor for iOS?
On macOS/iOS/iPadOS, you can download this all-in-one package on the App Store. It contains an editor side-by-side with an interactive top level, and is free and open source. To try small OCaml expressions, you can use an interactive top level, or REPL (Read-Eval-Print Loop).
Why do we need explicit casting in OCaml?
In OCaml you need to explicitly cast: The float_of_int function takes an int and returns a float. You might think that these explicit casts are ugly, time-consuming even, but there are several arguments in their favour. Firstly, OCaml needs this explicit casting to be able to work out types automatically, which is a wonderful time-saving feature.
