Questions about FloatArrays

Luciano Esteban Notarfrancesco lnotarfr at
Fri Jun 12 13:56:12 UTC 1998

I continue working on FloatArrays, and I have some implementation questions.
Squeak's Floats are 64 bits C doubles in the PowerPC ordering. In some 
plataforms (Intel for instance) the doubles are word-swapped, i.e. the 
lower 32 bits are swapped with the upper. I implemented FloatArray as a 
variableWord subclass of ArrayedCollection. I want to see FloatArrays 
as 'double *' from translated primitives... so I need to keep them in the 
ordering of the plataform in which Squeak is running. To handle this, I 
do the following:
	1) I keep a class variable in FloatArray (SwapWords) that says 
whether I need to swap words when storing and retriving Floats.
	2) I added to the method SystemDictionary|processStartUpList a 
line doing
		FloatArray startUp
	3) I implemented FloatArray class|startUp this way:
		((self with: 1.0) * 2.0) first = 2.0
			ifFalse: [SwapWords _ SwapWords not.
				self allInstancesDo: [ :each |
					each swap]].
	4) and I implemented FloatAray|swap as it's ovious.

What do you think about this scheme. Is all this right? Is there another 
way to do this, more close to the Squeak spirit?

Having access to 'double *' from translated primitives alows doing sound 
analysis, high-quality speech synthesis and speech recognition... that's 
way all this is too important to me.

Thanks in advance,

More information about the Squeak-dev mailing list