The native code compiler is ultimately the tool that most production OCaml code goes through. It compiles the lambda form into fast native code executables, with cross-module inlining and additional optimization passes that the bytecode interpreter doesn’t perform.

OCaml (/oʊˈkæməl/ oh-KAM-əl, formerly Objective Caml) is a general-purpose, multi-paradigm programming language which extends the Caml dialect of ML with object-oriented features.

Is OCaml a compiled or interpreted language? OCaml is compiled. However, the OCaml compiler offers a top-level interactive loop, that is similar to an interpreter.

Starting OCaml

1. In a terminal window, type utop to start the interactive OCaml session, commonly called the toplevel.
2. 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.

If Haskell is a niche language, then OCaml is a super-niche language. The OCaml community is much smaller. Where Haskell is doing more-or-less fine with libraries, OCaml has significantly less to propose. While Haskell has Text , OCaml mostly uses its built-in string type, which is simply an array of bytes.

The way -> is defined, a function always takes one argument and returns only one element. A function with multiple parameters can be translated into a sequence of unary functions.

OCaml-LSP is a language server for OCaml that implements Language Server Protocol (LSP). This project contains an implementation of a language server for OCaml and a standalone library implementing LSP.

OCaml comes with two compilers: ocamlc is the bytecode compiler, and ocamlopt is the native code compiler. If you don’t know which one to use, use ocamlopt since it provides executables that are faster than bytecode. Let’s assume that our program program has two source files, module1.ml and module2.ml.

Native-code object files produced by ocamlopt cannot be loaded in the toplevel system ocaml. The ocamlopt command has a command-line interface very close to that of ocamlc. It accepts the same types of arguments, and processes them sequentially, after all options have been processed:

From the file x.mli, the ocamlopt compiler produces a compiled interface in the file x.cmi. The interface produced is identical to that produced by the bytecode compiler ocamlc. Arguments ending in .ml are taken to be source files for compilation unit implementations.

The ocamlc command compiles individual ml files into bytecode files that have a cmo extension. The compiled bytecode files are matched with the associated cmi interface, which contains the type signature exported to other compilation units.