100hellos/sml repository overview

⁠Hello World! From sml.

Language page⁠ — context, influences, and learning notes on the 100hellos site.

Source on GitHub⁠ (100hellos/sml)

⁠Trying it

docker run --rm --platform="linux/amd64" 100hellos/sml:latest

⁠Modifying it

Read the repo README⁠, or fork the project⁠ and customize it.

For an interactive shell:

docker run --rm --platform="linux/amd64" --entrypoint="" -it 100hellos/sml:latest zsh

⁠Standard ML (SML) - Hello World!

Standard ML (SML) is a general-purpose, modular, functional programming language with compile-time type checking and type inference. Developed in the 1980s, it's known for its mathematical foundations and elegant design.

⁠About Standard ML

Standard ML was designed as a meta-language for the Edinburgh LCF theorem prover, but evolved into a standalone programming language. It features:

• Strong static typing with Hindley-Milner type inference
• Functional programming with immutable data structures by default
• Pattern matching for elegant control flow
• Module system for large-scale program organization
• Formal semantics - one of the few languages with a complete formal definition

⁠This Implementation

This container uses Poly/ML, a full implementation of Standard ML that's particularly well-suited for interactive development and deployment. Poly/ML is compatible with musl libc, making it perfect for Alpine Linux containers.

⁠Fun Facts

• Standard ML has influenced many modern languages including OCaml, Haskell, and Rust
• It was one of the first languages to feature garbage collection and polymorphic type inference
• The language definition fits in a relatively small book, yet it's computationally complete
• Robin Milner, one of SML's creators, won the Turing Award partly for his work on type systems

⁠Language Features Showcase

(* This simple "Hello World!" demonstrates SML's clean syntax *)
print "Hello World!\n";

(* But SML can do much more with functions and pattern matching *)
fun factorial 0 = 1
  | factorial n = n * factorial (n - 1);

(* Polymorphic data structures *)
datatype 'a option = NONE | SOME of 'a;

SML proves that functional programming can be both mathematically rigorous and practically useful!