Introduction
Lambda Zero is a minimalist pure lazy functional programming language with:
- All the standard Lambda Calculus features (first class functions, closures, currying, recursion, nested function definitions, ...)
- Lazy evaluation (infinite data structures, increased modularity, ...)
- Algebraic data types (enumerations, tuples, lists, trees, records/structs, maybe/optional types, either types, monads, ...)
- Pattern matching (case expressions, tuple destructuring, ...)
- Automatic garbage collection
- Semantic whitespace
- Unicode support (UTF8)
- User-defined lexically-scoped operator syntax and semantics
- Hindley-Milner static type inference (implemented in Lambda Zero)
- A self-interpreter
And the interpreter is less than 2500 lines of C code.
Sample Code
Hello World
main(input) ≔ "hello world"
Factorial
n ! ≔ n ⦊ case 0 ↦ 1; case ↑ n′ ↦ n ⋅ n′ !
Quicksort
sort ≔ case [] ↦ []; case n ∷ ns ↦ sort(ns ¦ (≤ n)) ⧺ [n] ⧺ sort(ns ¦ (> n))
Infinite list of natural numbers
iterate(f, x) ≔ x ∷ iterate(f, f(x))
(…) ≔ iterate(↑)
naturals ≔ 0 …
Infinite list of Fibonacci numbers
fibonaccis ≔ f(0, 1) where f(m, n) ≔ m ∷ f(n, m + n)
Infinite list of prime numbers
primes ≔ p(2 …) where p ≔ case [] ↦ []; case n ∷ ns ↦ n ∷ p(ns ¦ (% n ≠ 0))
Building
Make sure a C compiler is installed and run the make script in
the bootstrap-interpreter directory:
cd bootstrap-interpreter
./make
Running
From the bootstrap-interpreter directory:
./run SOURCEFILE
For example, try this sample program that prints out an infinite list of prime numbers:
./run test/samples/primes.zero
The run script prepends the prelude
to the SOURCEFILE and passes the result to main.
Stability
Breaking changes may be made at any time.