Talk:String (computer science)

message: I think something definitely needs to be added about the other meanings of string. Ukulele is already linked to this page, which is somewhat confusing.  Although, I'm not sure how much content can actually be provided for the other meanings.  Maybe this article should be moved to String (computer science) or something, and this page be turned into a disambiguation page. B4hand
::I propose renaming this article to Character string (computer science). Comments? - Bevo 17:03, 13 Jun 2004 (UTC)
thread_title:  Other meaninngs 

message: The lexicographical order on Σ* is not a well-ordering (for example, what is the least element in a*b?), but only a total order. fudo 13:53, 2 August 2005 (UTC)
replies: text: The least element of a*b is b. The lexicographical order on Σ* is indeed a well-ordering. --Pexatus 00:22, 19 March 2006 (UTC)
replies: text: No.  There is no least element of a*b if you use the alphabetical ordering a < b.  Assume there is some least element m; this means that m = a^{k}b for some non-negative integer k.  Note that n = a^{k+1}b is also in a*b.  n agrees m in k positions, but the k + 1th position of n is less than the k + 1th position of m, so n < m, which contradicts the assumption that there exists a least element of a*b.  Therefore, there is no least element of a*b. --Bkkbrad 16:28, 13 September 2006 (UTC)
thread_title:  Lexicographical order 

message: We should decide on just one spelling and capitalization of null. I vote for two L's.24.186.138.188 02:03, 2 May 2006 (UTC)
replies: text: "Null" generally refers to the "null character" (or a "null pointer"). "NUL" (all caps) is the mnemonic name (ASCII, EBCDIC, Unicode, etc.) of the "null character" code. — Loadmaster 18:35, 1 May 2007 (UTC)
thread_title:  Null and NUL 

message: Anyone know the history behind using the term "string" to mean a sequence of characters? I mean its not like a series of characters looks much like a ball of string... I assume it's origins are as a mathematical term, but it would be interesting to know how it came to such common use in computing.
:Presumably it comes from the rather obvious expression "a string of characters" (as in "these go some characters stringing by"), equivalent to "a string of pearls" or "a sequence of characters" or other similar phrases. — Loadmaster (talk) 16:27, 9 February 2008 (UTC)
replies: text: I heard that it originated because in the old days of physical type-setting, the type was held together in groups by literal string (rope). I don't have any references for this, though, so I can't back it up. Showeropera (talk) 20:48, 14 December 2017 (UTC)
thread_title:  Origin of the Term ? 

message: The edits I keep trying are to stop a whole army of uninformed but well-meaning programmers who think strlen() should parse and count the Unicode code points in a string. This is a totally useless definition and causing no end of grief when systems do this. For some reason otherwise intelligent programmers turn into these complete morons when presented with UTF-8 and this is actually seriously damaging any ability to do internationalization. If anybody can think of a wording that says these answers are different and that the fixed-size one is "better" it would help a lot. The reverted-to wording implies that the number of characters is the more important attribute, which is wrong.Spitzak (talk) 04:10, 29 May 2009 (UTC)
thread_title:  Trying to stop misuse of character encodings 

message: As well as the standard String type, .Net has a StringBuilder type. I think this is implemented as a linked list, but I'm not too sure. This would be worth adding to the Implementation section. N4m3 (talk) 09:35, 28 May 2011 (UTC)
thread_title:  StringBuilder .Net type 

message: I noticed this statement:
: Although formal strings can have an arbitrary (but finite) length, the length of strings in real languages is often constrained to an artificial maximum. [emphasis mine]
I would like a citation on that, what about languages with lazy evaluation like Clojure and Haskell?
 cycle "Is this finite? "
 ⇒ "Is this finite? Is this finite? Is this finite? Is this finite? ..."
 let shouting = 'a' : shouting in putStr shouting
 ⇒ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..."
—BiT (talk) 03:00, 8 December 2011 (UTC)
thread_title:  Only finite strings? 

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thread_title:  External links modified 

message: In order to make way for moving Draft:String to article space to take the place as the primary topic, I've posted a proposal at Talk:String#Requested move 16 January 2017 to move the disambiguation page currently at "String" to "String (disambiguation)". Your input would be helpful to establish a common consensus on whether or not this move, or something else, should be done. I look forward to your thoughts on the matter. The Transhumanist 22:50, 16 January 2017 (UTC)
thread_title:  Discussion to move "String" to "String (disambiguation)" 

message: In section String datatypes/Representations/Null-terminated the IBM 1401 word-mark terminated string is discussed.
:Somewhat similar, "data processing" machines like the IBM 1401 used a special word mark bit to delimit strings at the left, where the operation would start at the right. This bit had to be clear in all other parts of the string. This meant that, while the IBM 1401 had a seven-bit word, almost no-one ever thought to use this as a feature, and override the assignment of the seventh bit to (for example) handle ASCII codes.
That seventh bit idea could not have been implemented. The wordmark bit is hardware implemented. The MCW (Move Characters Wordmark) instruction for instance moved variable length fields terminating on the word mark. Numeric or alpha were treated no different. The Honeywell H200 H1200 H3200 and H4200 all had MCW instructions. Arithmetic operations also used wordmark field demarcation. The Honeywell computers had 8 bit memory having 6 data, a word mark and item mark bits.
Steamerandy (talk) 17:26, 24 April 2017 (UTC)
replies: text: It does sound like there are 1 or 2 extra bits per character. Are you saying there was no way for a program to read or write these extra bits? Or that the implementation was somehow different from having extra bits per character (perhaps it was a table of locations with the bit "set" and thus you were restricted to how many times it was turned on). I think it is obvious that instructions designed to use these bits to end strings won't work but that is not an explanation as to why this extra storage was not taken advantage of. It is also surprising that they would in effect reserve 1/4 of their memory for such a limited use, when you consider how incredibly expensive the memory was at that time.Spitzak (talk) 17:36, 24 April 2017 (UTC)
thread_title:  String length 

message: Siemens PLCs use a form of length prefixed string representation with 2 length information bytes (see Siemens Docs "Working with Strings in S7-SCL"). Maximum reserved memory is 256 bytes with maximum 254 bytes of actual text, where one byte denotes the allocated/reserved range for the string (the maximum count of characters allowed to be represented) and the other byte denotes the actual, currently valid length of the string. Maybe this could be added as length prefixed representation variant? --Ckonnerth (talk) 17:18, 15 December 2017 (UTC)
thread_title:  Another length prefixed representation 

message: Wondering why there's a bio-related image on this article's page, I don't see how it depicts what strings actually are in computer science.  — Preceding unsigned comment added by 67.165.80.152 (talk) 05:19, 30 March 2020 (UTC)
replies: text: I've changed the image to diagram a string. Though I haven't figured out how to make it the page image yet. TripleShortOfACycle (talk - contribs) - (she/her/hers) 14:19, 31 January 2021 (UTC)
replies: text: Now the page thumbnail works! It displays a diagram of a string when links to this page are hovered over. TripleShortOfACycle (talk - contribs) - (she/her/hers) 14:30, 31 January 2021 (UTC)
thread_title:  DNA?? 

message: As far as I know, it is also required that each string can be uniquely decomposed into its symbols. For example, if the alphabet itself consists of strings (as in Free_monoid#Free_generators_and_rank, or in the lead of Alphabet (formal languages), with Σ = {"0", "00"}), its symbols are distinct and unambiguous (as are the members of each mathematical set), but nevertheless, a string may be composed in different ways. I guess "unambiguous" is supposed to express the requirement of unique decomposition, but I'm not sure it is precise enough. The decomposition must be unambiguous, rather than just the symbols. - Jochen Burghardt (talk) 18:03, 13 May 2024 (UTC)
thread_title:  Distinct, unambiguous symbols