squeak-smalltalk / squeak-filesystem Goto Github PK

For interop with Monty's XMLParser package I need to add a method to String in the *fs-core-converting method category to get it to work.

Simply copy asReference and name it asFileReference

asFileReference
"Return an FSReference on disk"
^ FileSystem disk referenceTo: self

works like a charm

thanks for your hard work.

t

Expected: returns a reference of the grandparent directory.

Actual: returns a reference to the original file or directory.

ref := FileSystem disk workingDirectory / 'fstest.txt'.
ref writeStreamDo: [:stream |
	stream nextPutAll: 'abcde'].
ref contents. "'abcde'"
ref writeStreamDo: [:stream |
	stream nextPutAll: 'XYZ'].
ref contents "'XYZde'"

I would have expected just 'XYZ', analogously to FileStream class>>#forceNewFileNamed:.

But, is this a bug or intended behavior?

This issue can be avoided by sending assureDeleted to the reference prior to opening it for the second write. But this sounds less convenient than Squeak's built-in protocols ... And (to me) this was quite surprising and cost me a lot of time to debug. 😅

We noticed several compatibility issues that severely limit the applicability of FS in Squeak:

• Different behavior of next: In Squeak's Files package, it answers nil when at the end of the stream. FS raises an error.

  e.g., this makes it incompatible with Json:

  FileSystem memory in: [:fs |
  	fs / 'test.txt'
  		writeStreamDo: [:s |
  			'squeak' jsonWriteOn: s];
  		readStreamDo: [:s |
  			Json readFrom: s]] "⚡ Error: subscript is out of bounds: 8"

• No single-byte file stream option: In the Files package, StandardFileStream reads files byte per byte as opposed to MultiByteFileStream which uses a converter. All FSStreams require the use of a converter. Since there seems not to be something as a null converter (?), this makes it impossible to read files that were written using StandardFileStream.

• basicBack is missing on FSReadStream which is sent from UTF8TextConverter in response to #skip:. E.g.:

  FileSystem memory in: [:fs |
  	fs / 'test.txt'
  		writeStreamDo: [:s |
  			'squeak' jsonWriteOn: s.
  			s nextPut: Character null];
  		readStreamDo: [:s |
  			Json readFrom: s]] "⚡ MNU: #basicBack"

  Does this implementation make sense?

  FSReadStream>>basicBack
  	| result |
  	result := handle at: position - 1.
  	position := position - 1.
  	isBinary ifFalse: [result := result asCharacter].
   	^ result

• No support for data get/put protocol which limits usage for Sounds and others. See hpi-swa/Squot@4b35071 for more details. /cc @MariusDoe

In general, the question remains how much compatibility is desired ... but I would like it ... :-)