My favourite thing about SML is that it's a relatively idiot-proof language. It has something of Python's "one obvious way to do it" - a good chance of being ab

My favourite thing about SML is that it's a relatively idiot-proof language. It has something of Python's "one obvious way to do it" - a good chance of being able to understand someone else's code. This is partly because the language is small and features many sensible decisions, and partly because it isn't particularly malleable at the syntactic level (compared to your Lisps or Haskell). The tradeoff is that it can be more laborious than other functional languages. My code would be shorter if it had record updating, a single-character lambda syntax, contextual operators for real or int arithmetic, etc. Not only does it lack syntactic sugar for associative containers, it doesn't even have them in the standard library. Nor sorting, nor random numbers, nor complex numbers or matrices, nor uniform type-to-string formatting or string interpolation. Some of these holes can be filled by libraries, but then library choice becomes a problem. I can live with an awful lot of that though, given the relative clarity of the language, the really practical module system, and the delightful feeling you get when using a language standardised over 20 years ago that, once written, your code can stay written.