Awesome
Dale
Dale is a system (no GC) programming language that uses S-expressions for syntax and supports syntactic macros. The basic language is similar to C, with the following additional features:
- local type deduction;
- overloaded functions;
- anonymous functions;
- reference parameters;
- initialisers and destructors;
- variants;
- namespaces;
- modules;
- concepts; and
- compiler introspection.
It should be usable on most Linux/macOS/BSD systems where LLVM is able to be built. It has been tested on x86-64 (all), ARM64 (Linux, macOS) and ppc64le (Linux).
Documentation
Install
Dependencies
- LLVM (3.2-14.0)
- libffi
Out-of-tree (recommended)
mkdir ../build
cd ../build
cmake ../dale
make
make tests
make install
In-tree
cmake .
make
make tests
make install
Common build problems
Container (evaluation)
The container runs the REPL by default, but includes bash
(/bin/bash
) for more general testing/evaluation.
docker run -it tomhrr/dale
Examples
hello-world
(import cstdio)
(def main (fn extern-c int (void)
(printf "hello, world\n")))
> hello, world
hello-name
(import cstdio)
(def main (fn extern-c int (void)
(def name (var auto (p (const char)) "name"))
(printf "hello, %s\n" name)))
> hello, name
type-deduction
(import cstdio)
(import stdlib)
(def main (fn extern-c int (void)
(let ((a \ 1)
(b \ 2))
(printf "%d\n" (+ a b)))))
> 3
overloading
(import cstdio)
(import cstdlib)
(def Point (struct intern ((x int) (y int))))
(def + (fn intern Point ((a Point) (b Point))
(let ((r Point ((x (+ (@: a x) (@: b x)))
(y (+ (@: a y) (@: b y))))))
(return r))))
(def main (fn extern-c int (void)
(let ((a Point ((x 1) (y 2)))
(b Point ((x 3) (y 4)))
(c Point (+ a b)))
(printf "%d %d\n" (@: c x) (@: c y)))))
> 4 6
anonymous-functions
(import cstdio)
(import stdlib)
(def main (fn extern-c int (void)
(let ((anon-fn \ (fn int ((n int)) (* 2 n))))
(printf "%d\n" (anon-fn 5)))))
> 10
macros
(import cstdio)
(import stdlib)
(import macros)
(using-namespace std.macros
(def unless (macro intern (condition statement)
(qq do
(and (not (uq condition))
(do (uq statement) true)))))
(def main (fn extern-c int (void)
(unless (= 1 2)
(printf "1 does not equal 2\n"))
(return 0))))
> 1 does not equal 2
typed-macros
(import cstdio)
(import macros)
(using-namespace std.macros
(def + (macro intern ((a int) (b int) (c int))
(qq do (+ (uq a) (+ (uq b) (uq c))))))
(def main (fn extern-c int (void)
(printf "%d\n" (+ 1 2 3)))))
> 6
introspection
(import introspection)
(import stdlib)
(def Point (struct intern ((x int) (y int))))
(using-namespace std.macros
(def show-struct-details (macro intern (st)
(let ((name \ (@:@ st token-str))
(count \ (struct-member-count mc st)))
(printf "Struct: %s\n" name)
(printf "Member count: %d\n" count)
(let ((i \ 0))
(for true (< i count) (incv i)
(printf "Member %d: %s\n" (+ i 1) (struct-member-name mc st i))))
(nullptr DNode))))
(def main (fn extern-c int (void)
(show-struct-details Point)
0)))
> Struct: Point
> Member count: 2
> Member 1: x
> Member 2: y
error-reporting
(import introspection)
(import stdlib)
(using-namespace std.macros
(def assert-is-struct (macro intern (st)
(let ((count \ (struct-member-count mc st)))
(and (= -1 count)
(do (report-error mc st "struct type does not exist")
true))
(return (nullptr DNode)))))
(def main (fn extern-c int (void)
(assert-is-struct Point)
0)))
> ./error-reporting.dt:13:23: error: struct type does not exist (see macro at 13:5)
> ./error-reporting.dt:13:5: error: macro expansion error (see previous)
derivations
(import derivations)
(def Point (struct intern ((x int) (y int))))
(std.concepts.implement Struct Point)
(std.concepts.instantiate relations Point)
(def main (fn extern-c int (void)
(let ((p1 Point ((x 1) (y 2)))
(p2 Point ((x 3) (y 4))))
(and (!= p1 p2)
(do (printf "p1 and p2 are not equal\n") true))
(and (<= p1 p2)
(do (printf "p1 is less than or equal to p2\n") true))
(and (> p2 p1)
(do (printf "p2 is more than p1\n") true))
0)))
> p1 and p2 are not equal
> p1 is less than or equal to p2
> p2 is more than p1
containers
(import vector)
(import array)
(import algorithms)
(import cstdio)
(using-namespace std.concepts
(instantiate Vector int)
(instantiate Array int 10)
(instantiate copy (Iterator (Vector int))
(Iterator (Array int 10))))
(def main (fn extern-c int (void)
(let ((vec (Vector int))
(arr (Array int 10))
(i int))
(for (setv i 0) (< i 10) (incv i)
(push-back vec i))
(copy (begin vec) (end vec) (begin arr))
(let ((b \ (begin arr))
(e \ (end arr)))
(for true (!= b e) (setv b (successor b))
(printf "%d " (@ (source b)))))
(printf "\n")
0)))
> 0 1 2 3 4 5 6 7 8 9
variants
(import variant)
(import cstdio)
(def-variant Number ((Int ((a int)))
(Float ((a float)))))
(def main (fn extern-c int (void)
(let ((ni Number (Int 1))
(nf Number (Float 2.0))
(na (array-of 2 Number) (array ni nf)))
(for (i \ 0) (< i 2) (incv i)
(let ((nc Number (@$ na i)))
(case nc
(Int (printf "Number is int (%d)\n" (@:@ nc a)))
(Float (printf "Number is float (%f)\n" (@:@ nc a)))))))
0))
> Number is int (1)
> Number is float (2.000000)
Bugs/problems/suggestions
Please report to the GitHub issue tracker.
Discussion
The mailing list address is dale-lang@googlegroups.com. See also https://groups.google.com/forum/#!forum/dale-lang.
Licence
See LICENCE.