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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘UTF-16’ Category

Delphi, decoding files to strings and finding line endings: some links, some history on Windows NT and UTF/UCS encodings

Posted by jpluimers on 2019/12/31

A while back there were a few G+ threads sprouted by David Heffernan on decoding big files into line-ending splitted strings:

Code comparison:

Python:

with open(filename, 'r', encoding='utf-16-le') as f:
  for line in f:
    pass

Delphi:

for Line in TLineReader.FromFile(filename, TEncoding.Unicode) do
  ;

This spurred some nice observations and unfounded statements on which encodings should be used, so I posted a bit of history that is included below.

Some tips and observations from the links:

  • Good old text files are not “good” with Unicode support, neither are TextFile Device Drivers; nobody has written a driver supporting a wide range of encodings as of yet.
  • Good old text files are slow as well, even with a changed SetTextBuffer
  • When using the TStreamReader, the decoding takes much more time than the actual reading, which means that [WayBack] Faster FileStream with TBufferedFileStream • DelphiABall does not help much
  • TStringList.LoadFromFile, though fast, is a memory allocation dork and has limits on string size
  • Delphi RTL code is not what it used to be: pre-Delphi Unicode RTL code is of far better quality than Delphi 2009 and up RTL code
  • Supporting various encodings is important
  • EBCDIC days: three kinds of spaces, two kinds of hyphens, multiple codepages
  • Strings are just that: strings. It’s about the encoding from/to the file that needs to be optimal.
  • When processing large files, caching only makes sense when the file fits in memory. Otherwise caching just adds overhead.
  • On Windows, if you read a big text file into memory, open the file in “sequential read” mode, to disable caching. Use the FILE_FLAG_SEQUENTIAL_SCAN flag under Windows, as stated at [WayBack] How do FILE_FLAG_SEQUENTIAL_SCAN and FILE_FLAG_RANDOM_ACCESS affect how the operating system treats my file? – The Old New Thing
  • Python string reading depends on the way you read files (ASCII or Unicode); see [WayBack] unicode – Python codecs line ending – Stack Overflow

Though TLineReader is not part of the RTL, I think it is from [WayBack] For-in Enumeration – ADUG.

Encodings in use

It doesn’t help that on the Windows Console, various encodings are used:

Good reading here is [WayBack] c++ – What unicode encoding (UTF-8, UTF-16, other) does Windows use for its Unicode data types? – Stack Overflow

Encoding history

+A. Bouchez I’m with +David Heffernan here:

At its release in 1993, Windows NT was very early in supporting Unicode. Development of Windows NT started in 1990 where they opted for UCS-2 having 2 bytes per character and had a non-required annex on UTF-1.

UTF-1 – that later evolved into UTF-8 – did not even exist at that time. Even UCS-2 was still young: it got designed in 1989. UTF-8 was outlined late 1992 and became a standard in 1993

Some references:

–jeroen

Read the rest of this entry »

Posted in Delphi, Development, Encoding, PowerShell, PowerShell, Python, Scripting, Software Development, The Old New Thing, Unicode, UTF-16, UTF-8, Windows Development | Leave a Comment »

Long read about Unicode: You, Me And The Emoji: Character Sets, Encoding And Emoji – Smashing Magazine

Posted by jpluimers on 2017/11/07

A well worth long rad:

We all recognize emoji. They’ve become the global pop stars of digital communication. But what are they, technically speaking? And what might we learn by taking a closer look at these images, characters, pictographs… whatever they are 🤔 (Thinking Face). We will dig deep to learn about how these thingamajigs work. Please note: Depending on your browser, you may not be able to see all emoji featured in this article (especially the Tifinagh characters). Also, different platforms vary in how they display emoji as well. That’s why the article always provides textual alternatives. Don’t let it discourage you from reading though! Now, let’s start with a seemingly simple question. What are emoji?

[WayBackYou, Me And The Emoji: Character Sets, Encoding And Emoji – Smashing Magazine

Via: [WayBack] Everything you ever wanted to know about characters, encodings, glyphs… and, oh yeah, emoji: bit.ly/2fNKeW3Long, rewarding read. – Ilya Grigorik – Google+

Here is just the ToC:

TABLE OF CONTENTS LINK

  1. Character Sets And Document Encoding: An Overview
    1. Characters
    2. Character Sets
    3. Coded Character Sets
    4. Encoding
  2. Declaring Character Sets And Document Encoding On The Web
    1. content-type HTTP Header Declaration
    2. Checking HTTP Headers Using A Browser’s Developer Tools
    3. Checking HTTP Headers Using Web-based Tools
    4. Using A Meta Element With charset Attribute
    5. An Encoding By Any Other Name
  3. What Were We Talking About Again? Oh Yeah, Emoji!
    1. So What Are Emoji?
    2. How Do We Use Emoji?
    3. Character References
    4. Glyphs
    5. How Do We Know If We Have These Symbols?
    6. The Great Emoji Proliferation Of 2016
  4. Emoji OS Support
    1. Emoji Support: Apple Platforms (macOS and iOS)
    2. Emoji Support: Windows
    3. Emoji Support: Linux
    4. Emoji Support: Android
  5. Emoji On The Web
    1. Emoji One
    2. Twemoji
  6. Conclusion

–jeroen

Posted in ASCII, Development, Encoding, ISO-8859, ISO8859, Shift JIS, Unicode, UTF-16, UTF-8, UTF16, UTF8, Windows-1252 | Leave a Comment »

Some notes on stripping NULL characters and BOMs from files

Posted by jpluimers on 2017/05/31

A while ago I bumped into applications that write alternating UTF-16 and UTF-8 to files without checking what type of encoding the files were using.

So here are some notes to at least save some of the contents.

TODO: figure out how to strip the BOM.

–jeroen

Posted in Development, Encoding, Software Development, UTF-16, UTF-8, UTF16, UTF8 | Leave a Comment »

Some interesting encoding/Unicode/text articles on kunststube and links for test files of various encodings

Posted by jpluimers on 2016/08/17

After yesterdays post on Testing and static methods don’t go well together, I read around on Source (kunststube [WayBack]) a bit more and found these very nice articles on encoding,Unicode and text:

Related on those, some other nice readings:

–jeroen

Posted in Ansi, ASCII, CP437/OEM 437/PC-8, Development, EBCDIC, Encoding, ISO-8859, ISO8859, Shift JIS, Software Development, Unicode, UTF-16, UTF-8, UTF16, UTF8, Windows-1252 | Leave a Comment »

 
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