https://github.com/heapwolf/bale

A transpiler/module system polyfill for C++
https://github.com/heapwolf/bale

Last synced: 5 days ago
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A transpiler/module system polyfill for C++

• Host: GitHub
• URL: https://github.com/heapwolf/bale
• Owner: heapwolf
• Created: 2014-09-22T15:49:04.000Z (about 10 years ago)
• Default Branch: master
• Last Pushed: 2015-08-07T18:07:05.000Z (over 9 years ago)
• Last Synced: 2024-05-01T23:20:13.730Z (7 months ago)
• Language: C++
• Homepage:
• Size: 270 KB
• Stars: 38
• Watchers: 11
• Forks: 4
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# SYNOPSIS

A transpiler/module system polyfill for `C++`.

# MOTIVATION

C++ does not have a real module system. One is in the works but in the

meanwhile, here is a future-compatible polyfill. Inspired by 

[`this`](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2073.pdf), 

[`this`](http://isocpp.org/files/papers/n4214.pdf), clang's 

[`experimental module implementation`](http://clang.llvm.org/docs/Modules.html)

and the node.js [`module system`](http://nodejs.org/api/modules.html).

# PROJECT STATUS

Experimental. A work in progress.

# EXAMPLE

A modue is a discrete unit of code, encapsulated in a file. It exposes at 

least one public value, function, class, etc. Let's use the following file 

strcture as an example...

```

index.cc

pizza.cc

cheese.cc

cc_modules/

  serve/

    index.cc

```

## ./INDEX.CC

`index.cc` is the typical entry point for most programs.

```cpp

//

// import the file "pizza.cc" as "pizza".

//

import pizza "./pizza.cc";

//

// import the module "serve" as "serve".

//

import serve "serve";

int main() {

  serve.plate(pizza.make());

}

```

To understand how the math `module` is imported, read 

[`this`](http://nodejs.org/api/modules.html#modules_loading_from_node_modules_folders).

## ./PIZZA.CC

The module imported by the code in `index.cc`.

```cpp

#include 

#include 

//

// GLOBAL SCOPE

//

// Anything outside of export will be global, this will be 

// accessible from ANY file. you should not put anything here 

// unless you REALLY MEAN TO.

//

export {

  //

  // MODULE SCOPE

  //

  // Variables defined here are implicitly private, they are

  // not exported, this applies to varibles imported from other 

  // modules.

  //

  const double pi = M_PI;

  //

  // import the file "./cheese.cc" as "chz"

  //

  import chz "./cheese.cc";

  //

  // Variables found after the "public:" label are exported!

  //

  public:

    int make(int qty) {

      return qty * pi + chz.add(secret_sauce);

    }

  //

  // You can switch back and forth between public and private

  // by using the "private:" label.

  //

  private:

    int secret_sauce = 42;

}

```

## ./CHEESE.CC

This file happens to be included by `pizza.cc`.

```cpp

export {

  public:

    int add(int i) {

      return i*i;

    }

}

```

## ./CC_MODULES/SERVE/INDEX.CC

```cpp

export {

  public:

    void plate(int pizza) {

      cout << pizza << endl;

    }

}

```

# USAGE

```bash

bale ./test/input/index.cc

```