On Jan 22, 2004, at 1:59 PM, Avi Bryant wrote:
> Just out of curiosity - given this, why does FileStream not have 
> methods something like
>
> FileStream class>>fileNamed: fileName do: aBlock
> 	|file|
> 	file := self fileNamed: fileName.
> 	[aBlock value: file] ensure: file close
>

Others have pointed to some of the problems with this when opening the 
file goes wrong;  I'd add that there should be a check  for that before 
the block is evaluated, possibly with an exception being raised. That 
would make it important to consider what response the exception might 
elicit so that we could continue cleanly if appropriate.

Another problem was alluded to in the swamp of methods needed to mirror 
all the FileStream creation methods. My response would be along the 
lines of "don't do that". Instead, factor it out better. Keep the 
FileStream creation separate and make the block handling an instance 
method:-
myFile := FileStream newFileNamed:'wibble').
myFile ifNil:[FileStream newFileCreationException raise].
myFile doBlock:[:fl|
	fl nextPutAll: war and peace' asBook entireContents.
	fl thingy].
Or something a bit like that. I don't like the name #doBlock: but I 
can't think of anything better right now. #do: and #perform: are almost 
right but have rather specific meanings already.

Just a thought.

tim