| Standard ML of New Jersey | |
| Paradigms: | Multi-paradigm |
| Family: | ML |
| Developers: | Bell Laboratories, Princeton University Lucent Technologies, Yale University (FLINT Project), AT&T Research |
| Typing: | strong, static, inferred |
| Programming Language: | Standard ML, C |
| License: | BSD-like[1] |
| File Extensions: | .sml |
| Influenced By: | Standard ML |
| Influenced: | Mythryl |
Standard ML of New Jersey (SML/NJ; Standard Meta-Language of New Jersey) is a compiler and integrated development environment for the programming language Standard ML. It is written in Standard ML, except for the runtime system in C language. It was originally developed jointly by Bell Laboratories and Princeton University.[2] It is free and open-source software released under a permissive software license (BSD-like).
Its name is a reference both to the American state of New Jersey in which Princeton and Bell Labs are located, and to Standard Oil of New Jersey, the famous oil monopoly of the early 20th century.
SML/NJ extends the SML'97 Basis Library with several added top-level structures:[3]
SysInfo structure provides information about the runtime system, such as the operating system kind, type and version and whether or not the machine supports multiprocessing.[4]Weak structure provides support for weak pointers.[5]Susp structure implements the suspensions necessary for lazy evaluation (as opposed to eager evaluation).[6]Internals structure provides access to several of the compiler internals, including methods to instantiate and modify the signal table.[7]Unsafe structure provides unsafe access to data structures and runtime-system functions.[8]Also, SML/NJ provides some syntactic constructs that are not standard features of SML'97:[3]
#[''exp''<sub>0</sub>, ''exp''<sub>1</sub>, ..., ''exp<sub>n</sub>''<sub>−1</sub>] syntax and allows pattern-matching on them with analogous syntax.(''apat''<sub>1</sub> | ... | ''apat<sub>n</sub>'') => exp .Successor ML is a term used to describe the next version of the language. The documents describing it have been extracted from the SML/NJ '97 files and made available as a GitHub repository of TeX documents which the community is expected to collaborate and grow the language.[11] Successor ML features can be enabled using the command-line option -Cparser.succ-ml=true.
Since at least 1998,[12] MLton[13] is the standard bootstrapping compiler, and includes some support for Successor ML.
In 2008, work began on HaMLet,[14] a reference implementation of Successor ML written entirely in Standard ML.[15], HaMLet remains the only complete implementation of Successor ML, with added novel features.[16]
Since 2015, the evolution of SML/NJ geared towards evolving the Basis library[17] and adding support for the Successor ML definition with the release of version 110.79.[18]
At the end of 2020, 64-bit support was added with the release of version 110.99.[19]