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## toc
`toc` is a language which compiles to C.
---
### About
`toc` is currently in development. **It is not a stable language,
and there are almost definitely bugs right now.**
I would recommend against using it for anything big or important.
Many parts of it may change in the future.
`toc` improves on C's syntax (and semantics) in many ways,
To declare `x` as an integer and set it to 5,
you can do:
```
x := 5; // Declare x and set x to 5 (infer type)
x : int = 5; // Explicitly make the type int.
x : int; x = 5; // Declare x as an integer, then set it to 5.
```
`toc` is statically typed and has many of C's features, but
it is nearly as fast in theory.
See `docs` for more information (in progress).
`tests` has some test programs written in `toc`.
To compile the compiler on a Unix-y system, just run `./build.sh release`. You can supply a compiler by running `CC=tcc ./build.sh release`, or build it in debug mode without the `release`.
On other systems, you can just compile main.c with a C compiler. `toc` uses several C99 and a couple of C11 features, so it might not work on all compilers. But it does compile on quite a few, including `clang`, `gcc`, and `tcc`. It can also be compiled as if it were C++, but it does break the standard in a few places\*. So, MSVC can also compile it. The *outputted* code should be C99-compliant.
#### Why it compiles to C
`toc` compiles to C for three reasons:
- Speed. C is one of the most performant programming languages out there. It also has compilers which are very good at optimizing (better than anything I could write).
- Portability. C is probably the most portable language. It has existed for >30 years and can run on practically anything. Furthermore, all major languages nowadays can call functions written in C.
- Laziness. I don't really want to deal with writing something which outputs machine code, and it would certainly be more buggy than something which outputs C.
---
### `toc` Source Code
`toc` is written in C, for speed and portability. It has no dependencies, other than the C runtime library.
#### Build system
`toc` is set up as a unity build, meaning that there is only one translation unit. So, `main.c` `#include`s `toc.c`, which `#include`s all of `toc`'s files.
##### Why?
This improves compilation speeds (especially from scratch), since you don't have to include headers a bunch of times for each translation unit. This is more of a problem in C++, where, for example, doing `#include <map>` ends up turning into 25,000 lines after preprocessing. All of toc's source code, which includes most of the C standard library, at the time of this writing (Dec 2019) is only 22,000 lines after preprocessing; imagine including all of that once for each translation unit which includes `map`. It also obviates the need for fancy build systems like CMake.
#### New features
Here are all the C99 features which `toc` depends on (I might have forgotten some...):
- Declare anywhere
- `inttypes.h`
- Non-constant struct literal initializers (e.g. `int x[2] = {y, z};`)
- Flexible array members
The last three of those could all be removed fairly easily (assuming the system actually has 8-, 16-, 32-, and 64-bit signed and unsigned types).
And here are all of its C11 features:
- Anonymous structures/unions
- `max_align_t` and `alignof` - It can still compile without these but it won't technically be standard-compliant
#### More
See `main.c` for a bit more information.
---
### Version history
Here are the major versions of `toc`.
| Version | Description | Date |
| ------- | ----------- | ---- |
| 0.0 | Initial version. | 2019 Dec 6 |
| 0.1 | Constant parameter inference. | 2019 Dec 15 |
---
### Report a bug
If you find a bug, you can report it through [GitHub's issue tracker](https://github.com/pommicket/toc/issues), or by emailing pommicket@gmail.com.
Just send me the `toc` source code which results in the bug, and I'll try to fix it.
---
\* for those curious, it has to do with `goto`. In C, this program:
<pre><code>
int main() {
goto label;
int x = 5;
label:
return 0;
}
</code></pre>
Is completely fine. `x` will hold an unspecified value after the jump (but it isn't used so it doesn't really matter). Apparently, in C++, this is an ill-formed program. This is a bit ridiculous since
<pre><code>
int main() {
goto label;
int x; x = 5;
label:
return 0;
}
</code></pre>
is fine. So that's an interesting little "fun fact": `int x = 5;` isn't always the same as `int x; x = 5;` in C++.
|
