[swift-users] swift-users Digest, Vol 6, Issue 28

[Ken Burgett]

On 2016-05-30 10:00, swift-users-request at swift.org wrote:
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> Today's Topics:
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>    1. Re: Simple text file I/O with Swift 3 (Quinn "The Eskimo!")
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Mon, 30 May 2016 09:11:41 +0100
> From: "Quinn \"The Eskimo!\"" <eskimo1 at apple.com>
> To: Swift Users List <swift-users at swift.org>
> Subject: Re: [swift-users] Simple text file I/O with Swift 3
> Message-ID: <D94A5001-BE92-44FB-ADB8-CE0D68E62323 at apple.com>
> Content-Type: text/plain; charset=us-ascii
> 
> 
> On 28 May 2016, at 19:05, Ken Burgett via swift-users
> <swift-users at swift.org> wrote:
> 
>> print(buf)
> 
> 
> The trick here is to replace the above line with:
> 
>     print(String(validatingUTF8: buf))
> 
> `fgets` sets up `buf` to hold a C string, so you have to convert it to
> a Swift string.  How do you do this depends on the encoding of the
> bytes.  If you expect the C string to be UTF-8, then
> `String(validatingUTF8:)` is the way to go.
> 
> IMPORTANT: This conversion can fail, which is why the above will print
> a bunch of optional strings, and you will have to decide what to your
> program should do when it does.
> 
>                    *                   *                   *
> 
> btw This question came up recently.  See the thread for other
> suggestions about how to handle it.
> 
> <http://article.gmane.org/gmane.comp.lang.swift.user/1943>
> 
> Share and Enjoy
> --
> Quinn "The Eskimo!"                    
> <http://www.apple.com/developer/>
> Apple Developer Relations, Developer Technical Support, Core 
> OS/Hardware
> 
> 
> 
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> End of swift-users Digest, Vol 6, Issue 28
> ******************************************
Hi Quinn,

Thanks for the tip on  print(String(validatingUTF8: buf)), that does 
reproduce my input text, line for line, EXCEPT for wrapping every line 
in "Optional(line-of-text-with-terminator)", for example 
"Optional("import Glibc\n")".

So, how does wrapping a line of UTF8 text in another character string 
"Optional()" help me print the text?  Is Optional() some kind of 
function?  If so, how is it intended to be used?

-- 
Ken Burgett
Principal Software Engineer
Email: kenb at iotone.io
Office: 530.693.4449
Mobile: 831.332.6846
URL: www.iotone.co