Pros and cons of OCaml

The advantages and disadvantages of the OCaml programming language.

Pros:

  • More powerful type inference than any other language: OCaml even infers union and class types!

  • Powerful module system lets you parameterize modules over other modules easily and safely with full compile-time checking and minimal run-time overhead.

  • Structural typing of modules, polymorphic variants and classes improves brevity, closing the gap with dynamic languages, but can obfuscate error messages.

  • Powerful integrated macro system lets you alter the language's syntax on-the-fly and write parsers quickly and easily.

  • Good serial performance from the x64 code gen.

  • Easy-to-use REPL.

  • Lots of high-quality tools and libraries.

Cons:

  • No overloading can make numerical code over many different types (e.g. complex numbers, vectors and matrices) tedious.

  • Poor multicore support means poor performance on today's computers.

  • Some basic functionality missing (e.g. no 32-bit floats, no try..finally construct).

  • Some basic functionality is very inefficient (e.g. 32-bit ints).

  • Poor floating point performance from the x86 code gen.

  • 16MB limit on strings and arrays on 32-bit systems.

  • No way to override equality, comparison and hashing for new types and no way to catch errors created by this when the default structural versions are not applicable. Type classes are a solution to the former problem and equality types are a solution to the latter.

  • No value types means more memory use and worse performance in some important situations (e.g. filling a hash table with float keys and values in OCaml is 17× slower than F#).

Comments

Post a Comment

Popular posts from this blog

Bjarne Stroustrup is catching up

Bjarne Stroustrup, creator of the C++ programming language, once famously said "There are only two kinds of languages: the ones people complain about and the ones nobody uses". Interestingly, Bjarne has gone on the defensive in his recent lectures, completely changed his tune and is catching up with the conclusions that most former-C++ developers have arrived at. In a recent lecture Bjarne made many eyebrow-raising assertions. He is happy that people are no longer talking about C++ because that means it has succeeded. In reality, C++ demand in the job market has been in freefall for years and few new software projects are choosing it. He attacked computer scientists for copying data and said that "even babies don't do that", a very strange statement to make in a technical presentation. He also implied that other languages deep copy 10,000x10,000 matrices and claimed that a shared_ptr is "like an old fashioned garbage collector except it gets resource relea...
Read more

Does reference counting really use less memory than tracing garbage collection? Mathematica vs Swift vs OCaml vs F# on .NET and Mono

Image
Our previous post caused some controversy by questioning the validity of some commonly-held beliefs. Specifically, the beliefs that reference counting (RC) always requires less memory than tracing garbage collection (GC) and that tracing GCs require 3-4x more memory in order to perform adequately. We presented a benchmark written in Swift and OCaml and noted that the RC'd Swift implementation ran over 5x slower and required over 3x more memory than the tracing GC'd OCaml implementation. This observation disproves these beliefs in their strong form and even brings into question whether there is even any validity in the weak forms of those beliefs. After all, we have never seen any empirical evidence to support these beliefs in any form. We received a lot of criticism for that post. The vast majority of the criticism was not constructive but two valid points did arise. Firstly, although our result was anomalous it would be more compelling to see the benchmark repeated across a w...
Read more

Does reference counting really use less memory than tracing garbage collection? Swift vs OCaml

Image
The way software developers cling to folklore and avoid proper experimental testing of hypotheses really bothers me. I think perhaps the worst branch of computer science still riddled with myths and legends is memory management. Despite over half a century of research on garbage collection showing that reference counting is inferior to tracing garbage collections algorithms (even when almost all GC research restricts consideration to Java when much better algorithms have been known for years) there are still many people who claim otherwise. C++ developers obviously still believe that reference counted smart pointers are superior to tracing garbage collection but now other people are doing it too. People who should know better. This situation recently reared its ugly head again when Apple released a promising new programming language called Swift that shuns tracing garbage collection in favor of reference counting. Now, there are logical reasons for Apple to have chosen reference count...
Read more