C3 v0.1.5

C3 is a programming language with meta-programmation and a graph database embedded into the language. It aims to be the language for semantic programming, and programming the semantic web.

We are currently fundraising for the project to become real and there is a working prototype available at https://git.kmx.io/c3-lang/c3/, please see the https://www.kmx.io/en/donations.html page for helping out.

C3 is currently a programming language project, inspired by C, Elixir and Common Lisp. It could be described as C with Elixir modules, pattern matching, and a semantic object system. The idea is to plug modules, closures, pattern matching, a graph database and metaprogramming into C99 with an extremely small set of dependencies.

Usage

Compilation

git clone https://git.kmx.io/c3-lang/c3.git
cd c3
git submodule init
git submodule update
./configure
make

Add the sources to LD_LIBRARY_PATH

export LD_LIBRARY_PATH=$PWD/libc3/.libs:$PWD/libffi/.libs

Running the tests

make test

Running ic3

ic3/.libs/ic3

Running gdb

make gdb_ic3
make gdb_test

Structure

libc3

C3 is implemented using libc3 a small C99 library implementing the core of the language.

The library includes a parser and an interpreter for C3 code in C structures.

Support for large integers provided by libtommath.

Support for C function calls provided by libffi.

Modules are saved as facts databases.

Parser

The parser is recursive descent.

AST

The AST is represented as C3 data structures and can be meta-programmed in C.

Interpreter

Under development.

ic3

Interactive shell. Terminal I/O provided by linenoise.

Example :

$ make test
$ ic3/ic3
ic3> ic3> 1 + 1
2
ic3> 2 + 2
4
ic3> 3 + 3
6
ic3> 1 +
ic3> 1
2
ic3> double = fn (x) { x * 2 }
fn (x) { x * 2 }
ic3> double
fn (x) { x * 2 }
ic3> double(1)
2
ic3> double(2)
4
ic3> double(3)
6
ic3> double(4)
8
ic3> List.map((1, 2, 3, 4), double)
(2, 4, 6, 8)
ic3> List.reverse(List.map((1, 2, 3, 4), double))
(8, 6, 4, 2)

The List.map and List.reverse functions are defined in lib/c3/0.1/list.facts and can be modified in real time.

For example, without closing ic3 let’s redefine List.reverse, open an editor and change the line in lib/c3/0.1/list.facts from

replace {List.reverse, :fn, fn {
  (x) { List.reverse(x, ()) }
  ((), acc) { acc }
  ((a | b), acc) { List.reverse(b, (a | acc)) }
}}

to

replace {List.reverse, :fn, fn {
  (x) { List.reverse(x, ()) }
  ((), acc) { (:reversed | acc) }
  ((a | b), acc) { List.reverse(b, (a | acc)) }
}}

and check the results of the last command (up key) in ic3/ic3 :

ic3> List.reverse(List.map((1, 2, 3, 4), double))
(:reversed, 8, 6, 4, 2)

Don’t forget to revert the changes to list.facts.

c3s

Script interpreter. Works the same as ic3 but is not interactive.

TODO

• libc3
  • facts
    • negative facts : 4 + 2n = not 3 + 2n
    • with ignore variables
    • DONE atomic operations
    • DONE triple serial id
  • math
    • floating point numbers
  • variables
    • DONE = equal
    • DONE funcall
  • DONE boolean operators
  • DONE comparison operators
  • cast
  • arrays
    • DONE parse
    • DONE inspect
    • DONE [][][] data
  • lists
  • defmodule
  • structs
  • errors (setjmp, longjmp)
    • stacktrace
      • ffi ?
        • libdwarf
  • control structures
  • modules
    • DONE symbols
    • DONE as facts
    • DONE autoload (remember load time, compare with file time)
    • defmodule
  • functions
    • return
    • def
    • funcall
    • & &1
    • DONE fn () {}
  • macros
  • livebook
    • gaussian
  • buf_sha256
  • buf_popen
  • tests
    • DONE group tests by test case
  • DONE ci
  • DONE c function call
  • DONE infix operators
  • DONE load
  • DONE test_file_compare
  • DONE ffi
    • DONE types
    • DONE funcall