# C3 v0.1.7

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/](https://git.kmx.io/c3-lang/c3/),
please see the
[https://www.kmx.io/en/donations.html](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
```sh
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
```sh
export LD_LIBRARY_PATH=$PWD/libc3/.libs:$PWD/libffi/.libs
```

### Running the tests
```sh
make test
```

All the tests will be run. More specific targets exist :
```sh
make test_libc3
make test_ic3
make test_libc3_asan
make test_ic3_asan
make test_asan
```

### Running ic3
```sh
ic3/.libs/ic3
```

### Running gdb
```sh
make gdb_ic3
make gdb_test
```

### Adding or removing files from the source tree
```sh
make gen
./update_sources
```

Don't forget to commit your files and the modified sources.mk and
sources.sh files.


## 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](https://github.com/libtom/libtommath).

Support for C function calls provided by
[libffi](https://github.com/libffi/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](https://github.com/antirez/linenoise/tree/1.0).

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
   - DONE variables
      - DONE = equal
      - DONE funcall
   - DONE boolean operators
   - DONE comparison operators
   - DONE cast
   - DONE arrays
     - DONE parse
     - DONE inspect
     - DONE [][][] data
   - lists
   - structs
   - errors (setjmp, longjmp)
     - stacktrace
       - ffi ?
         - libdwarf
   - control structures
     - while
   - modules
     - DONE symbols
     - DONE as facts
     - DONE autoload (remember load time, compare with file time)
     - defmodule
   - functions
     - DONE fn () {}
     - DONE fn { () {0} (x) {x} }
     - return
     - def
     - funcall
     - & &1
   - 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

# License

## C3

```
/* c3
 * Copyright 2022,2023 kmx.io <contact@kmx.io>
 *
 * Permission is hereby granted to use this software granted the above
 * copyright notice and this permission paragraph are included in all
 * copies and substantial portions of this software.
 *
 * THIS SOFTWARE IS PROVIDED "AS-IS" WITHOUT ANY GUARANTEE OF
 * PURPOSE AND PERFORMANCE. IN NO EVENT WHATSOEVER SHALL THE
 * AUTHOR BE CONSIDERED LIABLE FOR THE USE AND PERFORMANCE OF
 * THIS SOFTWARE.
 */
```

## Unicode Character Database
```
UNICODE, INC. LICENSE AGREEMENT - DATA FILES AND SOFTWARE

See Terms of Use <https://www.unicode.org/copyright.html>
for definitions of Unicode Inc.’s Data Files and Software.

NOTICE TO USER: Carefully read the following legal agreement.
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YOU UNEQUIVOCALLY ACCEPT, AND AGREE TO BE BOUND BY, ALL OF THE
TERMS AND CONDITIONS OF THIS AGREEMENT.
IF YOU DO NOT AGREE, DO NOT DOWNLOAD, INSTALL, COPY, DISTRIBUTE OR USE
THE DATA FILES OR SOFTWARE.

COPYRIGHT AND PERMISSION NOTICE

Copyright © 1991-2022 Unicode, Inc. All rights reserved.
Distributed under the Terms of Use in https://www.unicode.org/copyright.html.

Permission is hereby granted, free of charge, to any person obtaining
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THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
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IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS
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```

## MSYS2 (win64)

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Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.

12. No Surrender of Others' Freedom.
If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.

13. Use with the GNU Affero General Public License.
Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such.

14. Revised Versions of this License.
The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.

Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.

If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program.

Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version.

15. Disclaimer of Warranty.
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

16. Limitation of Liability.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

17. Interpretation of Sections 15 and 16.
If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.

END OF TERMS AND CONDITIONS

How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.

    <one line to give the program's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>
        
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
    Also add information on how to contact you by electronic and paper mail.

If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:
    
    <program>  Copyright (C) <year>  <name of author>
    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    This is free software, and you are welcome to redistribute it
    under certain conditions; type `show c' for details.

The hypothetical commands 'show w' and 'show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”.

You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see <https://www.gnu.org/licenses/>.
                                                                
The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read <https://www.gnu.org/licenses/why-not-lgpl.html>.

