Herbert Vojčík wrote on 3. 7. 2018 11:21:
Sven Van Caekenberghe wrote on 3. 7. 2018 10:55:
On 3 Jul 2018, at 10:08, Herbert Vojčík <he...@mailbox.sk> wrote:
Sven Van Caekenberghe wrote on 2. 7. 2018 16:00:
On 25 Jun 2018, at 12:56, Herbert Vojčík <he...@mailbox.sk> wrote:
Peter Uhnák wrote on 23. 6. 2018 15:39:
Hi,
I'm starting to familiarize myself with new streams, and one thing
I've noticed is the removal of #lineEndConvention (which I use all
the time).
So a statement like this
aFile writeStreamDo: [ :stream |
stream lineEndConvention: #lf.
stream << '...'> ].
has to be written like so
aFile writeStreamDo: [ :rawStream | |stream|
stream := (ZnNewLineWriterStream on: rawStream) forLf.
stream << '...'
].
which feels very messy because I am mixing writing with the
configuration. And I don't even take account for buffered/encoded
decorators. Plus it increases the incidental complexity -- I need
another variable, and I can accidentally write to the wrong
stream, etc.
Would a method like #writeStream:do: (or
#writeStreamTransform:do:) make sense? E.g.
aFile writeStreamTransform: [ :stream | (ZnNewLineWriterStream on:
stream) ] do: [ :stream |
stream << '...'
]
aFile writeStreamDo: [ :rawStream |
(ZnNewLineWriterStream on: rawStream) in: [ :stream |
stream << '...' ] ].
As for transformation, I'd go for some more generic (functional?)
approach like:
aFile writeStreamDo: ([:x | ZnNewLineWriterStream on: x] pipe: [
:stream |
stream << '...' ]).
I like the first version with the (little known, but still standard
and clear) #in: selector.
I can't see how the second is 'better', as it looks equally
'complex' but adds a new selector, #pipe:
All this, IMHO.
It's a bit more focused on the task, that being transform incoming
argument. Cf.
#asString pipe: [ :aString | ... ]
instead of:
[ :anObject | anObject asString in: [ :aString | ... ] ]
IOW, scope of anObject is limited (and if using #selector you don't
even need to come up with a name, like the rawStream in examples
before).
OK, maybe, what is your definition for #pipe: then ?
Basically something like this:
(BlockClosure | Symbol) >> pipe: aBlock
^ [ :arg | aBlock value: (self value: arg) ]
Now that I think of, it is basically nothing more than function
composition, so it could have binary selector instead. That would save
parentheses, so the example would look like:
aFile writeStreamDo:
[ :x | ZnNewLineWriterStream on: x ] ++
[ :stream | stream << '...' ].
Herby
To separate the composition from the usage?
Thanks,
Peter
