c
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gravity-lang
mirror of https://github.com/marcobambini/gravity.git


			
				
					
						
						
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				<h4>INTRODUCTION</h4>
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         	<h1 class="section-header">API</h1><hr>
         				
			<p class="section-content">
				Gravity can be extended at runtime using C API. The right step to proceed is usually to create a new class, then add methods and properties to it and finally register that class inside the VM.
			</p>
			<pre><code class="cpp">
	// report error callback function
	void report_error (error_type_t error_type, const char *message,
	                   error_desc_t error_desc, void *xdata) {
		printf("%s\n", message);
		exit(0);
	}
	
	// function to be executed inside Gravity VM
	bool my_function (gravity_vm *vm, gravity_value_t *args,
	                  uint16_t nargs, uint32_t rindex) {
		// do something useful here
	}
	
	// Configure VM delegate		
	gravity_delegate_t delegate = {.error_callback = report_error};
	
	// Create a new VM
	gravity_vm *vm = gravity_vm_new(&delegate);
	
	// Create a new class
	gravity_class_t *c = gravity_class_new_pair (vm, "MyClass", NULL, 0, 0);
	
	// Allocate and bind closures to the newly created class
	gravity_closure_t *closure = gravity_closure_new(vm, my_function);
	gravity_class_bind(c, "myfunc", VALUE_FROM_OBJECT(closure));
	
	// Register class inside VM
	gravity_vm_setvalue(vm, "MyClass", VALUE_FROM_OBJECT(c));
			</code></pre>
			
			<p>Using the above C code a "MyClass" class has been registered inside the VM and ready to be used by Gravity:</p>
			<pre><code class="swift">		
	func main() {
		// allocate a new class
		var foo = MyClass();
		
		// execute the myfunc C function
		foo.myfunc();
	}
			</code></pre>
			
			<!--<h4 class="section-h4">Execute Gravity code from C</h4>
			<p></p>
			<pre><code class="cpp">
			</code></pre>-->
			
			<h4 class="section-h4">Bridge API</h4>
			<p>Gravity C API offers much more flexibility using the delegate bridge API.
			<br>TO DO: more information here.</p>
			<br>TO DO: post objc bridge.</p>
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