SML, or Standard Meta Language, is a programming language primarily used for symbolic and functional programming. It is a statically-typed language, meaning that variable types are checked at compile-time rather than runtime. SML is known for its strong type inference capabilities, allowing programmers to omit explicit type declarations while still ensuring type safety and preventing run-time errors.
Developed in the late 1980s, SML is characterized by its simplicity, expressive power, and emphasis on formal correctness. It supports modular programming through the use of modules, which enable code organization, encapsulation, and code reuse.
SML is based on the lambda calculus and supports features like higher-order functions, currying, pattern matching, and algebraic data types. It provides a rich set of built-in functions and data structures, including lists, tuples, and records. SML programs can be executed interactively or compiled into machine code, making it suitable for both prototyping and production-level software development.
The type system in SML guarantees program correctness by enabling static analysis of code. It ensures that functions are applied to the correct argument types and that data structures are accessed in a consistent and safe manner. This strong static typing makes SML programs less prone to runtime errors and easier to reason about.
SML has influenced several other programming languages and tools, including Haskell, OCaml, and Scala. Its clear and concise syntax, combined with its focus on correctness and modularity, make it a popular choice for teaching programming concepts and implementing language interpreters and compilers.
