The Sex language
Sex is a S-expressions language, which transpiles to C.
Sex is also Chicken, since all source processing and compile-time computations are written in Chicken.
And Chicken is R5RS Scheme.
Compilation
First, get yourself a Chicken. Second, some Chicken deps.
Install Chicken Eggs
By the way, there's a way to make Chicken install eggs non-globally. Refer to the documentation for more info: https://wiki.call-cc.org/man/5/Extension%20tools#changing-the-repository-location
chicken-install fmt getopt-long brev-separate test tree srfi-1 srfi-13
Compilation
make
Usage
Summary
Usage: sexc [options] filename [-- options-for-c-compiler]
Options:
--c-compiler=ARG Select C compiler. Defaults to value of SEX_CC
environment variable, or if it is empty, to cc
-c, --compile-object Compile object file instead of executable program
-E, --preprocess Emit C code
--public-interface Get module's public interface
-h, --help Show this help
-m, --macro-expand Emit macro-expanded Sex code
-o, --output=ARG Write output to file. Default file name is a.out.
If -E or -m options are provided, defaults to stdoutCompiling Hello World
sexc ./examples/hell-world.sex -o hello
That's it. Now you should have executable named hello in your
directory. Sex uses C under the hood, the default C compiler is cc,
but you can pass any using --c-compiler option, or by setting
SEX_CC environment variable.
Example
An example of Sex source:
(include stdio.h)
(pub fn int main ((int argc) (char **argv))
(puts "Hello from Sex!")
(var (array char 512) name)
(puts "What is your name?")
(scanf "%s" (cast char* &name))
(printf "Hello, %s!\n" name)
0)Compile and run:
~/dev/sex $ ./sexc ./example/hello-world.sex -o hello-world
~/dev/sex $ ./hello-world
Hello from Sex!
What is your name?
Alex
Hello, Alex!Features
Full C interoperability
Just (include "Your/Favourite/Library.h") and use it as you would
have is C.
Auto unkebabification
For hardcore fans of traditional Lisp naming convention,
Sex offers automatic unkebabification of all symbols, i.e. no more
ugly GL_ARRAY_BUFFER s in your code, they may be written in their
proper form: GL-ARRAY-BUFFER.
Modules
Each source file is a module. Module can provide public interface and
be imported by using (import path/to/module) expression. Module
search path consists of two parts: first is relative to the source
being compiled location, and the second is SEX_MODULE_PATH
environment variable.
Module's public interface consists of everything declared
pub. Structures, function, macros, types, variables can be
public.
Syntactic macros
Sex has support for syntactic macros. Macro definitions look like functions: they have a name, an argument list and a body. Macro should return Sex code.
Examples:
Structure with templated value type
(pub defmacro (list-T type)
(let ((list-type (cat 'list- type)))
`(struct ,list-type
((,type value)
((* ,list-type) next)))))
(list-T int)->
(struct list_int
((int value)
((* list_int) next)))Wrapper for checking return codes
(pub defmacro (check-sdl-return call message ret-code)
`((if (< 0 ,call)
(begin
(puts ,message)
(return ,ret-code)))))
(pub fn int init ()
(check-sdl-return
(SDL-Init SDL-INIT-VIDEO) "Failed to initialize SDL" 1)
...)->
(%fun int init ()
(if (< 0 (SDL_Init SDL_INIT_VIDEO))
(%begin (puts "Failed to initialize SDL") (return 1)))
...)
}Use an established environment for development
As Sex is S-expressions, you always have Emacs with paredit as your best option.
sex-mode.el
To harness the power of sex-mode, add the following lines to your
$HOME/.config/emacs/init.el:
(use-package sex-mode
:load-path "/path/to/sex"
:mode ("\\.sex\\'"))