E programming language - overview - syntax

I need a basic overview of E programming language - http://en.wikipedia.org/wiki/E_%28programming_language%29
Could please someone that has used it, or knows its syntax give me a brief example of the following things:
Declaring and assigning values to variables: integer, floating point, string.
Conditional and loop statements,
Functions - syntax, writing and using functions, example,
Arrays - syntax, definition, example
I know that there is already info about this in their website, but they seem to have just written it without much examples or explanations.
Also could you please point me to a site, where I can download an E compiler, in order to play a little bit with the syntax and get some exercise in writing basic programs (the links in their website are all broken/moved etc.)
Thank you for your time.
Best regards!

you can use the link
e programming

Related

Is there nice yaml documentation documenting most of functionality, written without yaml?

Official and most of yaml documentation is written in yaml itself. That is nice demonstration of language power. I get it, that's the main point of this documentation. But documenting language by using that yet unknown language is like solving puzzle. At least for me. Searching in this style of documentation really hard: "which operators can I use for string indentation?" In traditional documentating style one would use chapter say "string indentation". But here, while it's a nice demo, you need to read it all, and understand it all, which is extra subpar if you don't work with yaml daily. And yaml language spec is great, if you want to practice context (free?) grammar definition, but greatly unfit for quick search for basic questions.
My question is. Is there yaml documentation, using traditional structure, documenting most of features, not just very few? One html page, sections and paragraphs? I cannot find one, and I'm always struggling/wasting so much time trying to find something in this style of documentation. And every time I read anything, I feel I'm missing so much information, which is not shown, constantly learning X using not yet explained constructs.

Markup Language vs Programming Language

I was reading a article about it, and there was a line in that article which confused me a bit:
".....the markup language is used to present information whereas programming language is used to give instructions to a computer to perform a particular task."
The Computer still has to follow instructions of markup language to display information on the screen, right?
Please help! And Thank you!
You are right and the article is also right, but there's a bit of clarification.
A markup language (HTML, XAML, markdown, etc.) is an example of a declarative language, which says "this is what the result should be (e.g. what the screen should look like, what bit of input or output is expected, and so on). Declarative languages do not say anything about how to do something, but ultimately rely on an "engine" that imperatively gets to the results.
In contrast an imperative language describes each step that must be taken to achieve the end result (i.e. an algorithm). This is a set of instructions.
The reason your statement, "The Computer still has to follow instructions of markup language to display information on the screen" is correct is because a declarative language must rely on imperative operators and statements such as conditionals, looping, and so on (imperative) at a lower level to achieve the stated declarations.
Incidentally, referring back to your title... both are programming languages. They're just using different paradigms.

Using Datalog by itself, is it possible?

I am currently studying Datalog for my report in class, I only need to discuss basic syntax and a basic example.
I know Datalog is usually used as a query language and is usually only implemented to other languages such as Java, Lua, C, etc. but is it possible to teach Datalog only by itself, or am I required to use another language implementing it to show a simple working program?
There are a few online demos you can use:
http://iris-reasoner.org/demo
http://ysangkok.github.io/mitre-datalog.js/wrapper.html
https://repl.logicblox.com/ (docs here:
https://developer.logicblox.com/content/docs4/tutorial/repl/section/split.html )
I haven't tried it myself yet, but http://abcdatalog.seas.harvard.edu also looks nice and easy to run.
A complete overview is on Wikipedia: https://en.wikipedia.org/wiki/Datalog

Which tools can help in translating (as in french -> english and not C++ -> java) source code? [closed]

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I have some code that is written in french, that is the variables, class, function all have french names. The comments are also in french. I'd like to translate the code to english. This will be quite a challenge, since it's a 18K lines project and I'd like to know if there is any tool that could help me, especially with the variables/class/function names, since it will be error prone to rename them all.
Is there any tools that can help me? Advices?
edit : I'm not looking for machine translation. I'm looking for a tool that would help me translate the code. Let's say there is class name C and this class has a method named TraverserLaRue and I rename it CrossTheRoad I'd like all references to TraverserLaRue in all files to be translated as CrossTheRoad. However I don't want the method TraverserLaRue of class B to be translated.
I assume the langauge in question is one of the common ones, such as C, C++, C#, Java, ...
(You don't have a language with French keywords? I once encountered an entirely Swedish version of Pascal, and I gave up on working that).
So you have two problems:
Translating identifiers in the source code
Translating comments
Since comments contain arbitrary natural language text, you'll need an arbitrary translation of them. I don't think you can find an automated tool to do that.
Unlike others, however, I think you have a decent chance at translating the identifiers
and changing them en masse.
SD makes a line of source code "obfuscator" products. These tools don't process the code as raw text, rather they process the source code in terms of the targeted language; they accurately distinguish identifiers from operators, numbers, comments etc. In particular, they
operate reliably as need on just the identifiers.
One of the things these tools do is to replace one identifier name by another (usually a nonsense name) to make the code really hard to understand. Think abstractly of a map of identifier names I -> N. (They do other things, but that's not interesting here). Because you often want to re-obfuscate a file that has changed, the same way as an original, these tools allow you to reuse a previous cycle's identifier map, which is represented as list of I -> N pairs.
I think you can abuse this to do what you want.
Step 1: Run such an obfuscator on your original French code. This will produce a text file containing all the identifiers in the code as a map of the form
I1 -> N1
I2 -> N2
....
You don't care about the Ns, just the I's.
Step 2: Manually translate each French I to an English name E you think fits best.
(I have no specific suggestions about how to do this; some of the other answers here
have suggestions).
Some of the I's are likely to be library calls and are thus already correct.
You can modify the text obfuscation map file to be:
I1 -> E1
I2 -> E2
Step 3: Run the obfuscation tool, and make it use your modified obfuscation map.
It can be told to do that.
Viola, all the identifiers in your code will be changed the way you specify.
[You may get, as a freebie, the re-formatting of your original text. These tools can also format code nicely. Your name changes are likely to screw up the indentation/spacing in the original text so this is a nice bonus].
Any refactoring tool has a rename feature. Many questions on SO address language specific refactoring tools.
For the comments, you will have to handle them manually.
I did this with German code a while ago, but had mixed results because of abbreviations in names, etc. Using regular expressions, I wrote a parser that removed all of the language specific keywords and characters, then separated comments from the rest of the code, and now I had a lot of words that didn't necessarily mean anything to me by themselves. So I wrote a unique word finder that added them all to a ordered text file. Next stop was Google's language tools that attempted to translate every word in the list. I ran through the list to see if each word really translated, and if it did, I did a replace all in the code with the english equivalent. The comments I put back in with the complete translation, if it worked. What I found was that I ended up having to talk with someone who understood "Germish" to translate the abbreviations, slang terms, and mixed language pieces. So in short, regular expressions with a dictionary, unless someone has a real tool for this, which I would be interested in also.
You should definitely look into https://launchpad.net/rosetta
Ubuntu uses this to translate thousands of its packages written in hundreds of programming languages into hundreds of human languages, with updates for each new version. Truly herculean task.
edit: ...to clarify how Rosetta is used at Ubuntu: it modifies all natural language strings occuring in source code of the open-source apps, creating a language-specific source packages, which upon compiling create given kinds of binaries. Of course it does not edit binaries themselves.
First maintainers create "template files" which are something like "Patch with wildcards" - a set of rules what and where in the source tree needs to be translated, but not to what. Then Rosetta displays strings to be translated, and allows volunteering translators to provide translations to their language for each entry. Each entry can be discussed, modified, suggestions submitted and moderated. Stats are provided how much needs to be translated, which translations are unsure, which are missing etc. When the translation is complete, patch of given language is applied to the source creating its version for given language. Then a distribution is compiled from the modified sources.
This allows translation both for sources that use some external resources for multilingual allowing for language change on the fly, and for ones that have literal native language strings right in the source code, mixed with business logic.
When a new version of the package is released, template must be edited to include all new strings but it has quite good automation for preserving the existing ones. Of course only translations for new strings are required.
IMHO automatic tools won't be of any help here. Just translating variable and function names is not enough and will make the code worse because they cannot infer the original programmer intent when he choose a variable name.
Depending on what programming language this code is written to there are modern IDEs that might ease the refactoring but if you want to have good results manual code review is a must.
A good IDE will be able to list classes, methods, variables. There's also documentation generation tools that'll do that such as Javadoc for Java, Doxygen for many languages, etc.
To do the actual translation, there will be no tool that will perform well, or even to a satisfactory level. The only way to get something worthwile is to have a bilingual translator translate the terms. I've been doing freelance translations for many years, and can tell you that trying to have some machine do the translating is a waste of time. Many examples, choice of words, will be relevant to your culture and not the other. And that's just the tip of the iceberg.
Unless you find someone that can do the translation, I suggest you abandon the idea. Leave the source code as is. If a non-French speaker reads it, and needs to understand something, let them do the Google lookup. If they are native English speakers they'll probably do a better job of understanding the automatic translated stuff than you would, being French. When translating, you always want to translate into your native language.
For translating only comments you may try this simple utility I wrote (it's using Microsoft's Translator API): transource.

What are your language "hangups"? [closed]

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I've read some of the recent language vs. language questions with interest... Perl vs. Python, Python vs. Java, Can one language be better than another?
One thing I've noticed is that a lot of us have very superficial reasons for disliking languages. We notice these things at first glance and they turn us off. We shun what are probably perfectly good languages as a result of features that we'd probably learn to love or ignore in 2 seconds if we bothered.
Well, I'm as guilty as the next guy, if not more. Here goes:
Ruby: All the Ruby example code I see uses the puts command, and that's a sort of childish Yiddish anatomical term. So as a result, I can't take Ruby code seriously even though I should.
Python: The first time I saw it, I smirked at the whole significant whitespace thing. I avoided it for the next several years. Now I hardly use anything else.
Java: I don't like identifiersThatLookLikeThis. I'm not sure why exactly.
Lisp: I have trouble with all the parentheses. Things of different importance and purpose (function declarations, variable assignments, etc.) are not syntactically differentiated and I'm too lazy to learn what's what.
Fortran: uppercase everything hurts my eyes. I know modern code doesn't have to be written like that, but most example code is...
Visual Basic: it bugs me that Dim is used to declare variables, since I remember the good ol' days of GW-BASIC when it was only used to dimension arrays.
What languages did look right to me at first glance? Perl, C, QBasic, JavaScript, assembly language, BASH shell, FORTH.
Okay, now that I've aired my dirty laundry... I want to hear yours. What are your language hangups? What superficial features bother you? How have you gotten over them?
I hate Hate HATE "End Function" and "End IF" and "If... Then" parts of VB. I would much rather see a curly bracket instead.
PHP's function name inconsistencies.
// common parameters back-to-front
in_array(needle, haystack);
strpos(haystack, needle);
// _ to separate words, or not?
filesize();
file_exists;
// super globals prefix?
$GLOBALS;
$_POST;
I never really liked the keywords spelled backwards in some scripting shells
if-then-fi is bad enough, but case-in-esac is just getting silly
I just thought of another... I hate the mostly-meaningless URLs used in XML to define namespaces, e.g. xmlns="http://purl.org/rss/1.0/"
Pascal's Begin and End. Too verbose, not subject to bracket matching, and worse, there isn't a Begin for every End, eg.
Type foo = Record
// ...
end;
Although I'm mainly a PHP developer, I dislike languages that don't let me do enough things inline. E.g.:
$x = returnsArray();
$x[1];
instead of
returnsArray()[1];
or
function sort($a, $b) {
return $a < $b;
}
usort($array, 'sort');
instead of
usort($array, function($a, $b) { return $a < $b; });
I like object-oriented style. So it bugs me in Python to see len(str) to get the length of a string, or splitting strings like split(str, "|") in another language. That is fine in C; it doesn't have objects. But Python, D, etc. do have objects and use obj.method() other places. (I still think Python is a great language.)
Inconsistency is another big one for me. I do not like inconsistent naming in the same library: length(), size(), getLength(), getlength(), toUTFindex() (why not toUtfIndex?), Constant, CONSTANT, etc.
The long names in .NET bother me sometimes. Can't they shorten DataGridViewCellContextMenuStripNeededEventArgs somehow? What about ListViewVirtualItemsSelectionRangeChangedEventArgs?
And I hate deep directory trees. If a library/project has a 5 level deep directory tree, I'm going to have trouble with it.
C and C++'s syntax is a bit quirky. They reuse operators for different things. You're probably so used to it that you don't think about it (nor do I), but consider how many meanings parentheses have:
int main() // function declaration / definition
printf("hello") // function call
(int)x // type cast
2*(7+8) // override precedence
int (*)(int) // function pointer
int x(3) // initializer
if (condition) // special part of syntax of if, while, for, switch
And if in C++ you saw
foo<bar>(baz(),baaz)
you couldn't know the meaning without the definition of foo and bar.
the < and > might be a template instantiation, or might be less-than and greater-than (unusual but legal)
the () might be a function call, or might be just surrounding the comma operator (ie. perform baz() for size-effects, then return baaz).
The silly thing is that other languages have copied some of these characteristics!
Java, and its checked exceptions. I left Java for a while, dwelling in the .NET world, then recently came back.
It feels like, sometimes, my throws clause is more voluminous than my method content.
There's nothing in the world I hate more than php.
Variables with $, that's one extra odd character for every variable.
Members are accessed with -> for no apparent reason, one extra character for every member access.
A freakshow of language really.
No namespaces.
Strings are concatenated with ..
A freakshow of language.
All the []s and #s in Objective C. Their use is so different from the underlying C's native syntax that the first time I saw them it gave the impression that all the object-orientation had been clumsily bolted on as an afterthought.
I abhor the boiler plate verbosity of Java.
writing getters and setters for properties
checked exception handling and all the verbiage that implies
long lists of imports
Those, in connection with the Java convention of using veryLongVariableNames, sometimes have me thinking I'm back in the 80's, writing IDENTIFICATION DIVISION. at the top of my programs.
Hint: If you can automate the generation of part of your code in your IDE, that's a good hint that you're producing boilerplate code. With automated tools, it's not a problem to write, but it's a hindrance every time someone has to read that code - which is more often.
While I think it goes a bit overboard on type bureaucracy, Scala has successfully addressed some of these concerns.
Coding Style inconsistencies in team projects.
I'm working on a large team project where some contributors have used 4 spaces instead of the tab character.
Working with their code can be very annoying - I like to keep my code clean and with a consistent style.
It's bad enough when you use different standards for different languages, but in a web project with HTML, CSS, Javascript, PHP and MySQL, that's 5 languages, 5 different styles, and multiplied by the number of people working on the project.
I'd love to re-format my co-workers code when I need to fix something, but then the repository would think I changed every line of their code.
It irritates me sometimes how people expect there to be one language for all jobs. Depending on the task you are doing, each language has its advantages and disadvantages. I like the C-based syntax languages because it's what I'm most used to and I like the flexibility they tend to bestow on the developer. Of course, with great power comes great responsibility, and having the power to write 150 line LINQ statements doesn't mean you should.
I love the inline XML in the latest version of VB.NET although I don't like working with VB mainly because I find the IDE less helpful than the IDE for C#.
If Microsoft had to invent yet another C++-like language in C# why didn't they correct Java's mistake and implement support for RAII?
Case sensitivity.
What kinda hangover do you need to think that differentiating two identifiers solely by caSE is a great idea?
I hate semi-colons. I find they add a lot of noise and you rarely need to put two statements on a line. I prefer the style of Python and other languages... end of line is end of a statement.
Any language that can't fully decide if Arrays/Loop/string character indexes are zero based or one based.
I personally prefer zero based, but any language that mixes the two, or lets you "configure" which is used can drive you bonkers. (Apache Velocity - I'm looking in your direction!)
snip from the VTL reference (default is 1, but you can set it to 0):
# Default starting value of the loop
# counter variable reference.
directive.foreach.counter.initial.value = 1
(try merging 2 projects that used different counter schemes - ugh!)
In no particular order...
OCaml
Tuples definitions use * to separate items rather than ,. So, ("Juliet", 23, true) has the type (string * int * bool).
For being such an awesome language, the documentation has this haunting comment on threads: "The threads library is implemented by time-sharing on a single processor. It will not take advantage of multi-processor machines. Using this library will therefore never make programs run faster." JoCaml doesn't fix this problem.
^^^ I've heard the Jane Street guys were working to add concurrent GC and multi-core threads to OCaml, but I don't know how successful they've been. I can't imagine a language without multi-core threads and GC surviving very long.
No easy way to explore modules in the toplevel. Sure, you can write module q = List;; and the toplevel will happily print out the module definition, but that just seems hacky.
C#
Lousy type inference. Beyond the most trivial expressions, I have to give types to generic functions.
All the LINQ code I ever read uses method syntax, x.Where(item => ...).OrderBy(item => ...). No one ever uses expression syntax, from item in x where ... orderby ... select. Between you and me, I think expression syntax is silly, if for no other reason than that it looks "foreign" against the backdrop of all other C# and VB.NET code.
LINQ
Every other language uses the industry standard names are Map, Fold/Reduce/Inject, and Filter. LINQ has to be different and uses Select, Aggregate, and Where.
Functional Programming
Monads are mystifying. Having seen the Parser monad, Maybe monad, State, and List monads, I can understand perfectly how the code works; however, as a general design pattern, I can't seem to look at problems and say "hey, I bet a monad would fit perfect here".
Ruby
GRRRRAAAAAAAH!!!!! I mean... seriously.
VB
Module Hangups
Dim _juliet as String = "Too Wordy!"
Public Property Juliet() as String
Get
Return _juliet
End Get
Set (ByVal value as String)
_juliet = value
End Set
End Property
End Module
And setter declarations are the bane of my existence. Alright, so I change the data type of my property -- now I need to change the data type in my setter too? Why doesn't VB borrow from C# and simply incorporate an implicit variable called value?
.NET Framework
I personally like Java casing convention: classes are PascalCase, methods and properties are camelCase.
In C/C++, it annoys me how there are different ways of writing the same code.
e.g.
if (condition)
{
callSomeConditionalMethod();
}
callSomeOtherMethod();
vs.
if (condition)
callSomeConditionalMethod();
callSomeOtherMethod();
equate to the same thing, but different people have different styles. I wish the original standard was more strict about making a decision about this, so we wouldn't have this ambiguity. It leads to arguments and disagreements in code reviews!
I found Perl's use of "defined" and "undefined" values to be so useful that I have trouble using scripting languages without it.
Perl:
($lastname, $firstname, $rest) = split(' ', $fullname);
This statement performs well no matter how many words are in $fullname. Try it in Python, and it explodes if $fullname doesn't contain exactly three words.
SQL, they say you should not use cursors and when you do, you really understand why...
its so heavy going!
DECLARE mycurse CURSOR LOCAL FAST_FORWARD READ_ONLY
FOR
SELECT field1, field2, fieldN FROM atable
OPEN mycurse
FETCH NEXT FROM mycurse INTO #Var1, #Var2, #VarN
WHILE ##fetch_status = 0
BEGIN
-- do something really clever...
FETCH NEXT FROM mycurse INTO #Var1, #Var2, #VarN
END
CLOSE mycurse
DEALLOCATE mycurse
Although I program primarily in python, It irks me endlessly that lambda body's must be expressions.
I'm still wrapping my brain around JavaScript, and as a whole, Its mostly acceptable. Why is it so hard to create a namespace. In TCL they're just ugly, but in JavaScript, it's actually a rigmarole AND completely unreadable.
In SQL how come everything is just one, huge freekin SELECT statement.
In Ruby, I very strongly dislike how methods do not require self. to be called on current instance, but properties do (otherwise they will clash with locals); i.e.:
def foo()
123
end
def foo=(x)
end
def bar()
x = foo() # okay, same as self.foo()
x = foo # not okay, reads unassigned local variable foo
foo = 123 # not okay, assigns local variable foo
end
To my mind, it's very inconsistent. I'd rather prefer to either always require self. in all cases, or to have a sigil for locals.
Java's packages. I find them complex, more so because I am not a corporation.
I vastly prefer namespaces. I'll get over it, of course - I'm playing with the Android SDK, and Eclipse removes a lot of the pain. I've never had a machine that could run it interactively before, and now I do I'm very impressed.
Prolog's if-then-else syntax.
x -> y ; z
The problem is that ";" is the "or" operator, so the above looks like "x implies y or z".
Java
Generics (Java version of templates) are limited. I can not call methods of the class and I can not create instances of the class. Generics are used by containers, but I can use containers of instances of Object.
No multiple inheritance. If a multiple inheritance use does not lead to diamond problem, it should be allowed. It should allow to write a default implementation of interface methods, a example of problem: the interface MouseListener has 5 methods, one for each event. If I want to handle just one of them, I have to implement the 4 other methods as an empty method.
It does not allow to choose to manually manage memory of some objects.
Java API uses complex combination of classes to do simple tasks. Example, if I want to read from a file, I have to use many classes (FileReader, FileInputStream).
Python
Indentation is part of syntax, I prefer to use the word "end" to indicate end of block and the word "pass" would not be needed.
In classes, the word "self" should not be needed as argument of functions.
C++
Headers are the worst problem. I have to list the functions in a header file and implement them in a cpp file. It can not hide dependencies of a class. If a class A uses the class B privately as a field, if I include the header of A, the header of B will be included too.
Strings and arrays came from C, they do not provide a length field. It is difficult to control if std::string and std::vector will use stack or heap. I have to use pointers with std::string and std::vector if I want to use assignment, pass as argument to a function or return it, because its "=" operator will copy entire structure.
I can not control the constructor and destructor. It is difficult to create an array of objects without a default constructor or choose what constructor to use with if and switch statements.
In most languages, file access. VB.NET is the only language so far where file access makes any sense to me. I do not understand why if I want to check if a file exists, I should use File.exists("") or something similar instead of creating a file object (actually FileInfo in VB.NET) and asking if it exists. And then if I want to open it, I ask it to open: (assuming a FileInfo object called fi) fi.OpenRead, for example. Returns a stream. Nice. Exactly what I wanted. If I want to move a file, fi.MoveTo. I can also do fi.CopyTo. What is this nonsense about not making files full-fledged objects in most languages? Also, if I want to iterate through the files in a directory, I can just create the directory object and call .GetFiles. Or I can do .GetDirectories, and I get a whole new set of DirectoryInfo objects to play with.
Admittedly, Java has some of this file stuff, but this nonsense of having to have a whole object to tell it how to list files is just silly.
Also, I hate ::, ->, => and all other multi-character operators except for <= and >= (and maybe -- and ++).
[Disclaimer: i only have a passing familiarity with VB, so take my comments with a grain of salt]
I Hate How Every Keyword In VB Is Capitalized Like This. I saw a blog post the other week (month?) about someone who tried writing VB code without any capital letters (they did something to a compiler that would let them compile VB code like that), and the language looked much nicer!
My big hangup is MATLAB's syntax. I use it, and there are things I like about it, but it has so many annoying quirks. Let's see.
Matrices are indexed with parentheses. So if you see something like Image(350,260), you have no clue from that whether we're getting an element from the Image matrix, or if we're calling some function called Image and passing arguments to it.
Scope is insane. I seem to recall that for loop index variables stay in scope after the loop ends.
If you forget to stick a semicolon after an assignment, the value will be dumped to standard output.
You may have one function per file. This proves to be very annoying for organizing one's work.
I'm sure I could come up with more if I thought about it.

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