There is no idiom that I know of, but here is a fairly natural definition using an infix operator: # let (–) i j = let rec aux n acc = if n < i then acc else aux (n-1) (n :: acc) in aux j [] ;; val ( — ) : int -> … Read more
“What are the benefits of OCaml as a programming language” is indeed an opinion-based question, and one that I’m not going to tackle here. However, I work on the Hack team at Facebook, and have worked closely with the Flow team, so I can answer the question I think you intended to ask: “Why did … Read more
First of all, let’s ensure that we use terminology that is consistent with the OCaml type system and corresponding white papers. There is no such thing as “row type”† in the type system of OCaml, however, it has “row polymorphism” and we will discuss it below0. Row polymorphism is a form of polymorphism. OCaml provides … Read more
Here’s a sketch of an algorithm. It’s also the basis of Lennart Augustsson’s celebrated technique for compiling pattern matching efficiently. (The paper is in that incredible FPCA proceedings (LNCS 201) with oh so many hits.) The idea is to reconstruct an exhaustive, non-redundant analysis by repeatedly splitting the most general pattern into constructor cases. In … Read more
There’s no fundamental limitation of .NET that stops functors from being implemented in F#. True, they can’t be represented directly in .NET metadata, but neither can other F# language features like union types. Compilers for languages with functors (e.g., Standard ML, OCaml) have a pass called defunctorize; it works just like C++ template expansion, in … Read more
Compile with -g and set environment variable OCAMLRUNPARAM=b
Use the function string_of_int (see the documentation for Pervasives, the module containing the functions that are automatically made available in the top level namespace to al OCaml programs).
Caveat: I’m one of the authors of Batteries (although I’ve been out of touch for a year now) and the author of the about page linked above. The big differences are the following: Core is used daily in an industrial environment, while afaik Batteries doesn’t have the same following Core is maintained by one company, … Read more
Using regular expressions to validate a numeric range To be clear: When a simple if statement will suffice if(num < -2055 || num > 2055) { throw new IllegalArgumentException(“num (” + num + “) must be between -2055 and 2055”); } using regular expressions for validating numeric ranges is not recommended. In addition, since regular … Read more
The answer here is the same as for flip :-). Function composition isn’t defined in the OCaml standard library. In this case, it isn’t something I miss once in a while, I miss it all the time. The OCaml Batteries Included project defines function composition (in the order you give) using the operator -| in … Read more