is a programming language developed by JetBrains Research for educational purposes as an exemplary language to introduce
the domain of programming languages, compilers and tools. Its general characteristics are:
- procedural with first-class functions - functions can be passed as arguments, placed in data structures, returned and "constructed" at runtime via closure mechanism;
- with lexical static scoping;
- strict - all arguments of function application are evaluated before function body;
- imperative - variables can be re-assigned, function calls can have side effects;
- untyped - no static type checking is performed;
- with S-expressions and pattern-matching;
- with user-defined infix operators, including those defined in local scopes;
- with automatic memory management (garbage collection).
The name is an acronym for Lambda-Algol since the language has borrowed the syntactic shape of
operators from Algol-68; Haskell and OCaml can be
mentioned as other languages of inspiration.
The main purpose of is to present a repertoire of constructs with certain runtime behavior and
relevant implementation techniques. The lack of a type system (a vital feature for a real-word language
for software engineering) is an intensional decision which allows to show the unchained diversity
of runtime behaviors, including those which a typical type system is called to prevent. On the other hand
the language can be used in future as a raw substrate to apply various ways of software verification (including
type systems) on.
The current implementation contains a native code compiler for x86-32, written
in OCaml, a runtime library with garbage-collection support, written in C, and a small
standard library, written in itself. The native code compiler uses gcc as a toolchain.
In addition, a source-level reference interpreter is implemented as well as a compiler to a small stack machine. The stack machine code can in turn be either interpreted on a stack machine interpreter, or used as an intermediate representation by the native code compiler.
The language specification can be found here.
Prerequisites:
- gcc-multilib
- ocaml (>= 4.07.1) [http://ocaml.org]
- opam (>= 2.0.4) [http://opam.ocaml.org]
Installing:
opam pin add -n ostap https://github.com/dboulytchev/ostap.git#memoCPS(remember of "#" being a comment character in bash)opam pin add -y lama https://github.com/JetBrains-Research/Lama.git
Smoke-testing:
pushd tutorialmakepopd