Hi guys,<div><br></div><div>Over the weekend I had a look at NativeBoost FFI and I have enjoyed it. I really like this idea of taming the beast from high-level languages.</div><div>However I ran into some problems with the number of arguments one can pass to a smaltalk method (it turns out to be 15 at max)... That bad for FFI especially when you want to interface with legacy c code without touching the C-stuff (header, object files, etc).</div>

<div><br></div><div>In consequence I&#39;ve hacked my way around this limitation by introduction of a new type of arguments that we can pass to callouts. I call these arguments &quot;in object arguments&quot;.</div><div>
The idea isn&#39;t new and is very simple, instead of passing 20 arguments to your function just pass one an array with all the arguments you need.�</div>
<div>Where it turns interesting is that I think we can pass more than just an array we can pass real objects (think about ParameterObject) that hold in their instance variables the arguments we want.</div><div><br></div>
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lets say that we want to call a function &quot; int function(int x, int y)&quot;, now with the NativeBoost wrapper we will get a call something like</div><div><br></div><div>function_x: x y: y</div><div>&lt;primitive: #primitiveNativeCall module: #NativeBoostPlugin&gt;</div>

<div>^ self call: #( int function (int x, int y))</div><div><br></div><div>the idea is to replace x: y: with only one argument</div><div><br></div><div>function: anArgument</div><div>&lt;primitive: #primitiveNativeCall module: #NativeBoostPlugin&gt;</div>

<div>^�self call: #( int function (int anArgument@1, int anArgument@2))</div><div><br></div><div>or even</div><div><br></div><div>function: aPoint</div><div><div>&lt;primitive: #primitiveNativeCall module: #NativeBoostPlugin&gt;</div>

<div>^�self call: #( int function (int aPoint@x, int aPoint@y))</div></div><div><br clear="all"><div>Yes this last example breaks the encapsulation a little bit by acceding directly to the instance variable of aPoint... but... well�</div>

<div><br></div><div>another example will be:</div><div><br></div><div>function_arg1: a arg2: b</div><div><div>&lt;primitive: #primitiveNativeCall module: #NativeBoostPlugin&gt;</div><div>^�self call: #( int function (int a@1, int a@2, int b@3, int b@1, int a@6))</div>

</div><div><br></div><div><br></div><div>Well that&#39;s all that I did this weekend.</div><div><br></div><div>Attached to this mail you can find a file-out of these developments... they include:</div><div>1. the idea presented above</div>

<div>2. refactoring of NBFFICallout argument loader creation</div><div>3. a small &quot;extension/fix&quot; of the skipSpace method (in spec parser) to skip all separators not just spaces (think about a header definition with tabs)</div>

<div><br></div><div>Well that&#39;s it folks, enjoy</div><div>Cheers</div>-- <br><font color="#999999">Dr. Ciprian TEODOROV<br>Ing</font><span style="color:rgb(153,153,153)">�</span><font color="#999999">nieur�D�veloppement�CAO<br>

<br>t�l : 06 08 54 73 48</font><br><font color="#999999">mail :�<a href="mailto:ciprian.teodorov@gmail.com" target="_blank">ciprian.teodorov@gmail.com</a><br><a href="http://www.teodorov.ro/" target="_blank">www.teodorov.ro</a></font><br>


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