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Compile and run Pure code online instantly with HCODX. Our free cloud-based Pure compiler supports real-time execution, standard input, syntax highlighting, and code download. No installation or configuration required. Start coding in Pure now.
Run Pure instantly without installing any IDEs or configuring environments. Our cloud-based Pure handles libraries, runtimes, and dependencies automatically so you can focus on writing code.
Whether you are studying algorithms in Pure, practicing data structures in Pure, or exploring functional programming, our tool provides real-time stdout/stderr feedback with interactive standard input support.
HCODX is a free online compiler and code runner: write code in your browser, execute it on a cloud sandbox, and interact with your program through a live terminal. Students use it for coursework and interview practice; developers use it to test snippets in 85+ languages without setting up a local environment.
Pure is a modern functional term-rewriting language created by Albert Gräf in 2008 as a successor to the Q language. It marries the equational style of Mathematica with dynamic typing, lazy evaluation on demand, and LLVM-backed JIT compilation that delivers performance competitive with C in tight numeric loops. Pure has first-class macros, list and stream comprehensions, multiple-dispatch pattern matching, and an interactive REPL. Run Pure programs in this browser-based compiler — no LLVM toolchain install, no Pure interpreter setup.
// Hello World in Pure — equational definitions + list comprehension
greet name = "Hello, " + name + "!";
langs = ["Python", "Rust", "Go", "Pure"];
greetings = [greet n | n = langs];
do puts greetings;
// Bonus: factorial via term-rewriting equations
fact 0 = 1;
fact n = n * fact (n - 1) if n > 0;
puts ("10! = " + str (fact 10));
// => 10! = 3628800Use Pure for mathematical computing (it's particularly strong at symbolic algebra thanks to Mathematica-style rewriting), algorithm prototyping where you want to write equations directly as code, computer-algebra-system extensions, scientific-computing experiments, and teaching declarative programming. Pure's LLVM backend makes it surprisingly fast for a small-community language — competitive with Haskell on many numeric benchmarks while keeping a syntax that reads like a math paper. HCODX is a free online Pure editor, runner and interpreter — an IDE-grade compiler and playground to write and run code online, execute code with live output and live preview, no downloads or web server required.
Both are functional, but Pure is dynamically typed (no compile-time type system to satisfy) and uses term-rewriting as its core semantics where Haskell uses lazy graph reduction with a strong static type system. Pure's syntax is closer to Mathematica — you write equations directly. Pure also has a much smaller standard library and ecosystem than Haskell, which suits research and mathematical scripting more than production back-end work.
Term rewriting means your program is a set of equations — like 'fact 0 = 1; fact n = n * fact (n-1);' — and the runtime keeps applying matching equations to terms (expressions) until no more rules apply. It's the same paradigm Mathematica uses for symbolic math, generalised as a programming model. Algorithms end up reading like mathematical definitions, which is a huge win for code that maps directly to math.
Pure 0.68 (2020) was the last major release; the language is feature-complete and the community is small but active on the github.com/agraef/pure-lang repository. It's a great choice for one-off scripts, academic work, and personal projects where you want maximum expressiveness per line of code, but production teams would generally pick a language with a larger ecosystem like Haskell, OCaml, or Scala.
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