I have some doubts about the standard ISO 2022:
What's the difference between using 94-(0x21 - 0xFE) and using 96-(0x20 - 0xFF)?
Why, for example in EUC-CN, code in CS1 only use limited area (94- 96-)? Why doesn't it occupy the all? For compatibility or other reasons?
Looking forward to your replies and thx~
You should have a look at Ken Lunde's book "CJKV Information Processing" (2nd edition).
Q1: What's the difference between using 94-(0x21 - 0xFE) and using 96-(0x20 - 0xFF)?
A1: If the answer isn't in the book, you'll have to find the people on the ISO 2022 committee and ask them about their design questions :-)
Q2: Why, for example in EUC-CN, code in CS1 only use limited area (94- 96-)? Why doesn't it occupy the all? For compatibility or other reasons?
A2: See A1.
Now some reverse questions:
RQ1: Are ISO-2022-CN and EUC-CN still in use anywhere? I notice that the Python language supplies codecs for ISO-2022-JP (7 different varieties) and ISO-2022-KR but not for ISO-2022-CN (or -CN-EXT). Lunde says that ISO-2022-CN wasn't widely used.
RQ2: Why have you tagged your question with gb2312 and gbk?
RQ3: What is your interest in ISO-2022-CN etc?
Related
Is there a complete listing of all theories/logics that z3 supports? I have consulted this SMTLIB Tutorial which provides a number of logics, but I do not believe that the list is exhaustive. The z3 documentation itself doesn't seem to specify which logics are supported.
I ask because I have an smt file which cannot be solved under any of the logics in the SMTLIB Tutorial (when specified with 'set-logic'), but can be solved when no logic is specified.
For Z3, I have not seen such a list in the documentation, but you can find it in the source code if you really want to know. The list starts around line 65 of check_logic.cpp. I parsed out the list for you using a scary awk one-liner, and found this as of May 20, 2016 (between Z3 4.4.1 and 4.4.2):
"AUFLIA", "AUFLIRA", "AUFNIRA", "LRA", "QF_ABV", "QF_AUFBV", "QF_UFBV", "QF_AUFLIA", "QF_AX", "QF_BV", "QF_IDL", "QF_RDL", "QF_LIA", "QF_LRA", "QF_NIA", "QF_NRA", "QF_UF", "QF_UFIDL", "QF_UFLIA", "QF_UFLRA", "QF_UFNRA", "UFLRA", "UFNIA", "UFBV", "QF_S"
You can compare this to the official list of SMT-LIB 2 logics.
Probably more importantly for you is what the "best logic" is for your application. It sounds like you have a large and varying set of problems that you want Z3 to apply whatever tactics it can to. In that case, for now, it's best to leave the logic unspecified. The problem is that in SMT-LIB v2.0 there was no all-encompassing logic -- the largest logic by some standards was AUFNIRA, but this does not include, for example, bit vectors. As a result, CVC4 introduced a non-standard ALL_SUPPORTED logic, and Z3 performs best for some classes of problems when no logic is specified. This shortcoming of the SMT-LIB 2.0 standard is addressed in SMT-LIB 2.5, with a new logic called "ALL". However, this is not yet supported by either Z3 or CVC4.
You specify a logic in Z3 to ensure that Z3 uses a particular strategy and engine that is typically useful for the class of formulas expressed in this logic.
If no logic is specified, then Z3 falls back to a default mode. There is no logic corresponding to
this default mode: it integrates multiple engines.
I am trying to build an iOS application. In one of the screens the user can type something in a search bar and I have to take same action for different spellings of the same word.
For eg: User can type "elephant" or "alephant" or "elefant". I have to take same action for all these three words.
Is there any library that identifies these words as similar ones ? I cannot use spellchecker as I need this in languages other than english also ..
I did some research and I found that there are some phonetic algorithms like Text::soundex for achieving this on server side. Wondering if any libraries there for iOS ?
Thanks in advance !!
A better alternative to Soundex would be Double Metaphone or, even better, Metaphone 3. You don't say what language you are using, but both of these algorithms are available in C++, C#, and Java
There's no soundex available in for example NSString, but if that's what you want, it's fairly easy to implement. Here's a—albeit horribly formatted—soundex NSString category from CocoaDev.
You could also use the Levenstein Distance algorithm to catch simple spelling errors. Also easy to implement (read the Wikipedia article for the details), but here's a NSString category for that.
Before you use these algorithms, normalize the input. There's the amazing CFStringTransform class in Core Foundation (see this great article about it on NSHipster—especially the last part about normalization) that automatically can transform different language inputs into normalized forms.
I heavily use strings in a project so what i am looking for is a fast library for handling them.I think the Boyer-Moore Algorithm is the best.
Is there a free solution for that ?
You can consider the following resources implementing Boyer–Moore algorithm:
Boyer-Moore Horspool in Delphi 2010
Boyer-Moore-Horspool text searching
Search Components - Version 2.1
Boyer-moore, de la recherche efficace
Last Edit:
The StringSimilarity package of theunknownones project is a good source for fuzzy and phonetic string comparison algorithms:
DamerauLevenshtein
Koelner Phonetik
SoundEx
Metaphone
DoubleMetaphone
NGram
Dice
JaroWinkler
NeedlemanWunch
SmithWatermanGotoh
MongeElkan
CAUTION: Answering to the comment rather than to the question itself
There is (or, rather, was, because it has been abandoned currently) a Delphi unit (namely!) FastStrings which implements Boyer–Moore string search algorithm by heavy use of inline assembler. Is is one you are looking for?
As side note: project homepage is defunct now as long as author's e-mail, so i'm finding reuse (and modification and, naturally, any further development) of this code rather problematic given how restrictive are licensing terms.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Does my variable naming convention have a name?
Notation in question is described by example below:
T for type
P for pointer
F for field
A for argument
L for local
et cetera, there is at least S missing from the list, but i'm not sure which string it designates.
First 3 prefices was with Delphi since very beginning, last 2 i've noticed relatively recently. I'd like to know notation name (if any), and read some normative whitepaper (and adopt then, may be).
Zarko Gajic has a pretty good Delphi-specific list here:
http://delphi.about.com/od/standards/l/bldnc.htm
Personally, I find some conventions like this useful. I still remember my first language FORTRAN, where the convention for Integers was to start them any letter from I to N, and it was easy to remember because they are the first two letters of INteger.
Section "3.3 Field Naming" of the Object Pascal Style Guide by Charles Calvert gives a brief but good guide as to when to use Hungarian notation, and also what single character identifier names are appropriate. My FORTRAN background (8 character names max) also made me use "N" as the count of items and led to code such as:
DO 10 I = 1, N
DO 20 J = I, N
...
20 CONTINUE
10 CONTINUE
Ouch! The memories hurt.
My personal favorite of all these standards, is to obey the standards already established in the code you're in, and not try to impose a different standard 50% of the way through, and to religiously avoid bikeshed discussions.
But if you press me really hard, I'll admit, I prefer Charlie Calvert's standards as used by JVCL devs, same as "section 3.3" link by LKessler above.
Hungarian notation.
With modern IDEs (including Delphi's) many people (myself included) feel it is no longer necessary.
EDIT: Technically this is not true Hungarian notation, as sometimes the prefix indicates the scope rather than the type.
It's possible to do interesting things with what would ordinarily be thought of as typesetting languages. For example, you can construct the Mandelbrot set using postscript.
It is suggested in this MathOverflow question that LaTeX may be Turing-complete. This implies the ability to write arbitrary programs (although it may not be easy!). Does anyone know of any concrete example of such a program in LaTeX, which does something highly unusual with the language?
In issue 13 of The Monad Reader, Stephen Hicks writes about implementing the solution to an ICFP contest (involving Mars rover navigation) in TeX, with copious use of macros. Amusingly, the solution's output when typeset is a postscript map of the rover's path.
Alternatively, Andrew Greene wrote a BASIC interpreter in TeX (more details). This may count as slightly perverse.
\def\K#1#2{#2}
\def\S#1#2#3{#1#3{#2#3}}
The pgfmath library still amazes me. But on a more Turing-related note: it is possible to write an actual Turing machine in TeX, as per http://en.literateprograms.org/Turing_machine_simulator_(LaTeX). It's just a nifty way of using expansions in TeX.
PostScript is Turing complete as well, if you'll read the manual you'll be amazed by the general programming capabilities of it (at least, I was).
I'm not sure if this qualifies as programming per se, but I've recently starting doing something a bit like Object Oriented stuff in LaTeX. (You don't need to know any maths to follow the following.) In recent papers, I've been writing about categories, which have objects and morphisms. Since there've been quite a few of those, I wanted a consistent style so that, say, 𝒞 was a category with typical object C and typical morphism c. Then I'd also have 𝒟 with D and d. So I define a "class", say "category" (you need to be a mathematician to understand the joke there), and declare that C is an instance of this class, and then have access to \ccat, \cobj, \cmor and so forth. The reason for not doing \cat{c}, \obj{c}, and \mor{c}, and so forth, is that sometimes these categories have special names and so after declaring the instance, I can modify it's name very easily (simply redefine \ccat - well, actually \mathccat since \ccat is a wrapper which selects \mathccat in math mode and \textccat in text mode). (Of course, it's a little more complicated than the above suggests and the OO stuff really comes in useful when I want to define a new category as a variant of an old one (it can even deal with the case where the old one doesn't exist yet.).)
Although it may not qualify as actual programming, I am using it in papers and do find it useful - the other answers (so far) have more of the feel of showing off the capabilities of LaTeX than of a sensible solution to a practical problem.
I know of someone who wrote the answer to an ACM contest problem in LaTeX.