- The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!), Joel Spolsky, 2003-10-08
- Characters and Combining Marks, The Unicode Consortium
- If a programmer is going to read only one document summarizing Unicode this is the one to read. It presents the key terms, such as text element, character, code unit, code point, and grapheme cluster, canonical equivalence, and compatibility decomposition.
- Unicode Standard Annex #29, Unicode Text Segmentation
- another Unicode document that is particularly relevant to programmers.
- ISO Standard 10646:2012 (and electronic inserts), Information technology -- Universal Coded Character Set (UCS)
- The ISO standard based on the character coding portions of Unicode
- ISO Amendment 10646:2012/Amd 1:2013 (and electronic inserts)
- The first amendment to ISO646:2012
- Book Review: Unicode Explained, by Jukka K. Korpela (alternate), Cameron Laird
See Also edit
- Unicode and UTF-8
- Unicode file reader
- A little Unicode editor
- i18n tester
- quickly shows what parts of Unicode are supported by your fonts
- dead keys for accents
- a tiny package allowing easier entering of accented characters
- i18n - writing for the world
- some random korean text
- Unicode fonts and tools for X11
- The classic X bitmap fonts in an ISO 10646-1/Unicode extension
- Multilingual Unicode TrueType Fonts on the Internet, Slavic Text Processing and Typography
- links to free TrueType fonts for larger or smaller subsets of the Unicode.
- Welcome to Computers and Writing Systems, SIL International
- source of free Unicode fonts in various languages, with a particular focus on more obscure languages and local dialects.
- I18n Guy
- a website dedicated to program internationalization
- Character Sets And Code Pages At The Push Of A Button, Tex Texin
- code charts from all over.
- ascii2uni and uni2ascii
- bidirectional conversion between Unicode and more than thirty 7-bit ASCII equivalents, including RFC 2396 URI, RFC 2045 Quoted Printable format, and the \uXXXX notation used in Tcl
- Deja Vu Fonts
- a set of free fonts based on the Vera fonts, and providing a wider range of characters
Description editUnicode is complex. Whereas ASCII defines 127 characters, Unicode defines 1,114,112 code points, and characters are composed of one or more code points. Unicode provides code charts, but doesn't stop there. The following things are also specified by Unicode:
- character classes such as capitalization, and sort order
- Rendering hints
- composition of characters from individual codepoints, and decomposed into individual code points.
- normalization of code-point sequences
- hyphenation and line-breaking
- boundaries of words and sentences
- user interaction for processes such as text deletion and highlighting
RS: Until version 3.0, 16 bits (\u0000-\uFFFD: the "Basic Multilingual Plane", BMP) were sufficient for any Unicode. From 3.1, we must expect longer codes - up to 31 bits long, as specified in ISO 10646. Why 31 bits? Because that is the maximum that can be expressed in UTF-8: 6 bytes, omitting the taboo values \xFE and \xFF.
1111110a 10aaaaaa 10bbbbbb 10bbcccc 10ccccdd 10dddddd, where small letters stand for "payload" bits of bytes a..d, highestmost has only 7 bits
Newsgroups: comp.lang.tcl From: r_haer...@gmx.de Date: Sat, 26 Apr 2008 11:55:45 -0700 (PDT) Local: Sat, Apr 26 2008 2:55 pm Subject: unicode - get character representation from \uxxx notation Hello, to show my problem see the following example: > set tcl_patchLevel 8.5.3b1 > set str "n\u00E4mlich" nämlich > set c 0xE4 > set str "n\\u[format %04.4X $ch]mlich" n\u00E4mlich How do I get the \u00E4 in the character representation let's say iso8859-1 ? > encoding convertto iso8859-1 $str Newsgroups: comp.lang.tcl From: billpo...@alum.mit.edu Date: Sat, 26 Apr 2008 14:21:27 -0700 (PDT) Local: Sat, Apr 26 2008 5:21 pm Subject: Re: unicode - get character representation from \uxxx notation To convert the hex number expressed as a string 0x00e4 to a Unicode character, use: format "%c" 0x00e4 You can then use encoding convertto to convert this to another encoding, e.g.: encoding convertto iso8859-1 [format "%c" 0x00e4]
LV 2008-07-08:I've a request from a developer concerning whether Tcl is capable of handling characters larger than the Unicode BMP. His application was using tdom and it encountered the 𝒜 character, which is a script-A, unicode value 0x1D49C, which tdom reports it can't handle because it is limited to UTF-8 chars up to 3 bytes in length.What do Tcl programmers do to properly process the longer characters?Note this is in an enterprise setting. Finding a solution is critical in the publishing (web or print) arena.RS 2008-07-09: Unicode out of BMP (> U+FFFF) requires a deeper rework of Tcl and Tk: we'd need 32 bit chars and/or surrogate pairs. UTF-8 at least can deal with 31-bit Unicodes by principle.LV During July, 2008, there was some discussion in the TCT mailing list  (let's see how long that URL lasts...) about ways that the Tcl code itself could evolve to handle things better. But for right now, users have to face either dealing with their wide unicode via a different programming language in some way (whether converting wide characters to some other similar character, using some sort of macro representation, etc.)
AMG, 2015: It's been seven years since the above discussion. What progress has been made?tcl.h contains the comment:
- "Tcl is currently UCS-2 and planning UTF-16 for the Unicode string rep that Tcl_UniChar represents. Changing the size of Tcl_UniChar is not supported."
AMG: How are combining characters handled? They seem to be treated as individual characters, and they're only combined in the display. Trouble with this is that the cursor can go between combining characters, along with similar problems like cutting a string in the middle of what's called a grapheme cluster.