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Reading multi parts of a file concurrently
I have a need to read first half and second half of a file concurrently. Is there any best practices for this scenario? BTW, I did research on DispatchIO but it turned out DispatchIO is all about asynchronous operations on a single file handle; it cannot perform parallel reading. // naive approach Task { fileHandle.read(into:buffer) } Task { // seek to file size / 2 fileHandle.read(into:buffer) }
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1k
Jan ’24
FileManager.enumerator and URL problem
I have the following pseudo code: func load(at packageURL: URL) { let realPackageURL = packageURL.resolvingSymlinksInPath() guard let it = fileMan.enumerator(at: realPackageURL) for case let fileURL as URL in it { print(fileURL) // Get filename relative to package root directory let relativeFileName = String(filePath.suffix(filePath.count - packagePath.count)) } } When called with "file:///tmp/some.app", the enumerated fileURL is actually file:///private/tmp/GIMP.app/Contents/ packageURL.resolvingSymlinksInPath() actually does nothing, I assume /tmp is a hard link. This makes it impossible to get a correct relative path. Is there any remedy for this?
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627
Jan ’24
@escaping vs @nonescaping closures
I know this is a frequently asked question, but... After reading many articles on the net, I am still not sure if I have a solid understanding of the logics behind the design. One of my puzzles around this question is - Is the Swift compiler clever enough so that I can solely rely on its warnings/errors?
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773
Jan ’24
TableView.makeView question
Is it possible that I bypass tableView.makeView so that I can create a NSTableCellView on the fly (based on some logics)? func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? { if NSTableColumn.identifier.rawValue == "labelColumn" { let myCellView = NSTableCellView() myCellView.textField.strinValue = "label text" return myCellView } else { let complexView = loadFromNib() // of NSTableCellView // populate complexView return complexView } }
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452
Jan ’24
"zero length data" error
I had a customer feedback about a "zero length data" error which was captured using an exception handler and displayed using NSAlert. My app employs [NSURLSession dataTaskWithURL:] to download XML and image data. But I got no idea what it is about. I assume it's related to NSData, but this error never happened before (for years). Does anyone have any idea about the source of this error?
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902
Feb ’24
Swift if statement with multiple conditions
I just want some experts on Swift to confirm that the following syntaxes are equivalent: if a > b, c > d { } if a > b && c > d { } I consulted "The Swift Programming Lanugage (version 5.7)" but the book does not cover this issue. But I believe it's true because my tests show they are the same.
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956
Feb ’24
How change NSTableView's width using code?
I calculate cell view's width in func tableView(_ tableView: NSTableView, sizeToFitWidthOfColumn column: Int). I have a need to resize the tableview's width to just match total width of all cell views' (without scrollbars). But it seems changing tableview's width does not work: tableView.bounds.size = CGSize(width: w, height: tableView.bounds.height) I suspect that I should change its clipping view or enclosing scrollview, but don't have any idea on this. Any help?
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684
Mar ’24