## Command line programs

### SAI script runner: sai-run

`sai-run` can be executed on the command line with a path to a SAI object. 

    sai-run [path/objectname]

The object will be created and instantiated immediately.  

For example:

    // HelloWorld.sai
    object HelloWorld main 1.0.0
    
    Instantiate task
      debug 'Hello world!'
    
Then compiling and executing:
  
    $ sai-run HelloWorld 
    
    Hello world!


Code for the builder is located in the `runner.sai` script.


### SAI script compiler: sai-build

This doc is a little out of date, execute sai-build to see current notes.

`sai-build` can be executed on the command line with a path to a SAI object. 

    sai-build [path/objectname]

A full prototype for that object will be written to STDOUT.  If your project has multiple objects, you will need to compile each object independently and save it to its own `.js` file.  

Example:

    $ sai-build sample/Impossible/Impossible >impossible.js
    $ node impossible.js
    
    Mathemetician's "Impossible" puzzle solver.
    Initial candidate count: 2304
    Phase 2 candidate count: 145
    Phase 3 candidate count: 86
    Results candidate count: 1
    Solution 1: X=4, Y=13; sum=17, product=52
    

The prototype will require the `sai-library` package.

Code for the builder is located in the `builder.sai` script.


#### Pre-compiled stand-alone projects

If you wish to omit the use of `sai-language` in your project, you must compile everything before-hand.

The run-time library will not use the dynamic **create** loader, instead expecting all objects to be precompiled and available by the run-time loader which uses the native `require`.


#### Compiled SAI as main()

To mark an object for immediate instantiation when `require`d (e.g. when run on the command line), add **main** to the object definition as follows:

    object [objectname] main [objectversion]
      
When the resulting Javascript file is executed, a single version of the object will be instantiated, thus invoking the **Instantiate** task.

For example:

    // HelloWorld.sai
    object HelloWorld main 1.0.0
    
    Instantiate task
      debug 'Hello world!'
    
Then compiling and executing:
  
    $ sai-build HelloWorld >helloworld.js
    $ node helloworld.js
    
    Hello world!
    
When using `sai-run` the **main** clause is not necessary, but still best practice.