There are pages that indicate ANTLR works with Objective-C, but I can find no documentation or examples of actually using ANTLR with an Objective-C target. I even dug through the source code and have found no examples.
Any guidance, anyone?
The parser generator that emits Objective-C code is old and doesn't work. You'll have to use the C generator, and the C generator's documentation is worse than useless.
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It is possible to do OO programming in pure C.
Some strategies use pre-processor macros to make it easier and less error prone. Some strategies involve adding new syntax which is expanded to pure c by a pre-processor, along with a base object class and some methods for memory management.
It seems that Objective-C began as a project much like this
Do any tools exist that allow objective-c syntax to be processed to pure C?
Without having explored it, it seems do-able.
Just to clarify, I am not asking about compiling iOS code to other platforms, or asking about ports of the cocoa library to other platforms, I am wondering about ways of using oo techniques in pure-C, using Objective-C syntax and a preprocessor or precompilation step.
Portable Object Compiler. It's not capable of compiling modern Objective-C, but it sounds like it is perfect for what you're asking. Look here at a discussion of POC's shortcomings
The situation for C++ is more interesting. Cfront was the original C++ compiler that produced C code, but besides being long outdated it was commercial and cannot be (easily?) downloaded today. Fortunately, there is Comeau C/C++ which is supposedly very modern and standards compliant. It costs $50.
However, I wouldn't expect to get very readable C code from either of them (especially the full-featured Comeau).
It is possible to do oo programming in pure c?
Yes, as oo is a matter of philosophy. Look at glib and how you can do c style object: http://developer.gnome.org/glib/
Apple did it with Core Fundation: https://developer.apple.com/library/mac/#documentation/CoreFoundation/Conceptual/CFDesignConcepts/CFDesignConcepts.html#//apple_ref/doc/uid/10000122i
By the way: Do any tools exist that allow objective-c syntax to be processed to object oriented pure c?
Yeah: gcc (GCC 4.6 according to Wiki, never actually checked ;)) and clang, tools that you are usin everyday.
This is the Objective-C Runtime who make the obj-c obj-cAble, so you need libobjc.A.dylib library too. You can write obj-c in pure c code, since all message '[]', '#' directive and other obj-c stuff are converted in c after compilation.
No it's not possible, as all special (non-identifier) symbols of Objective-C can not be used as preprocessor macros. At least not with the standard C preprocessor.
Other preprocessors may be able to define macros with non-identifier names, although I don't know of any.
When talking about preprocessors in the early days of Objective-C (and also about C++) it's probably (and in the case of C++, definitively) a custom made parser that instead of outputting assembler or objective code outputted C code.
I love static analysis and compile-time checks, almost to a fault, but most of my day job is in Objective-C. To resolve this tension, I'd like to be able to write my own analysis tools that I can run on my Objective-C projects.
But googling around the Internet suggests that people are having a hard time putting together a complete Objective-C grammar. One site basically recommends giving up.
I did find a grammar on the ANTLR website, but when I fired it up, I couldn't get it to parse anything at all. For example, it responded to the line:
void x();
with src/main/resources/somecode.m line 1:0 no viable alternative at input 'void'
:(
I took a closer look at the grammar and found the following disheartening disclaimer:
it's a work in progress, most of the .h file can be parsed
But I need something that can parse both interface and implementation.
Is there a complete Objective-C 2.0 grammar out there somewhere? I'd prefer something that can work with Scala (so anything Java compatible, like ANTLR, would be perfect), but at this point I'd be willing to adapt something designed for another parser toolkit.
As others mentioned, Clang would be the right solution. You can provide your own AST consumers, i.e. classes that will be invoked when going over the AST, leaving you not having to worry about parsing or messing with grammar.
Clang supports Objective-C in its entirety, and there's a lot of classes already in the static analyzer that you can model your own checks after. (in clang/lib/StaticAnalyzer/Checkers).
That directory contains a lot of static analyzer checkers, but you can also just create a normal AST consumer. Refer to http://code.google.com/p/chromium/wiki/WritingClangPlugins for more information.
Clang is a static analysis tool that has support for Objective-C. I've found it very useful in the past.
http://clang-analyzer.llvm.org/
clang is extensible; you can extend their existing static analysis or create your own. llvm / clang is architected as a series of libraries you can link to (dynamically or statically). A great starting point is the ARC (automatic reference counting) migrator library, which is responsible for statically analysing and rewriting objective-c code.
arcmt-test is a small example program that consumes the ARC migrator library.
You can use OCDepend, it's a static analysis tool based on Clang that simplifies managing Objective-C code quality and provides a highly flexible code query framework.
There is a very cool sounding technique called Shape Context matching, which can be used in an Image Recognition application to match an "unknown image" against a known "image library." There are numerous descriptions of the concept documented on the web (mostly all variations of the same original paper), for example: http://www.eecs.berkeley.edu/Research/Projects/CS/vision/shape/sc_digits.html
I found a JAVA implementation and a MATLAB implementation of the algorithm described in the paper, but I cannot find an objective-c implementation. Anyone know if there is any objective-c code out there, anywhere, implementing these techniques? I sure would like to take advantage of it, rather than trying to write that stuff myself!
Here you can find an interesting c++ implementation (for non-commercial usage, didn't check it yet.. see the downloads):
http://www.umiacs.umd.edu/~zhengyf/PointMatching.htm
I'm currently searching for a Java implementation of the algorithm. Could you please provide a link to the implementation you found?
The original matlab code can be downloaded at:
www.eecs.berkeley.edu/Research/Projects/CS/vision/shape/sc_digits.html
I also found a C# implementation:
http://www.pscode.com/vb/scripts/ShowCode.asp?txtCodeId=7465&lngWId=10
Take a look at OpenCV. It is implemented in C so it can be used in obj-c pretty easily.
Does Objective C have a documentation framework similar to JavaDoc where documentation can be generated from the source code?
Doxygen! You can use it for many languages, including Objective-c
Good news for all! :D Finally after waiting a long time Apple has introduced a parser comments for our projects. According to the new features in XCode 5:
Project documentation from framework API reference documentation and
structured comments in your own source code are displayed in the quick
help panel and in code completion popover views. Doxygen and HeaderDoc
structured comments are supported formats.
and from the Clang 3.2 release notes:
Clang parses the comments and can detect syntactic and semantic errors
in comments. These warnings are off by default. Pass -Wdocumentation
flag to enable warnings about documentation comments.
If you want to see an example of this new feature I recommend you take a look at the following article: Documentation in Xcode 5
Doxygen is quite popular among Obj-C developers.
You could have a look to HeaderDoc wich is the apple documentation framework similar to Java.
Appledoc has become very popular. . . version 1 was based on Doxygen, whereas version 2 was written from the ground up.
It doesn't quite have all the features of Doxygen (charts, enums, C++ classes, etc), but what it does offer is beautifully formatted docs in HTML of IDE integrated format.
Also interesting to note is the following:
The CocoaPods tool includes Appledoc documentation for the libraries that it installs. Quite handy.
If I were looking to create my own language are there any tools that would help me along? I have heard of yacc but I'm wondering how I would implement features that I want in the language.
Closely related questions (all taken by searching on [compiler] on stackoverflow):
Learning Resources on Parsers, Interpreters, and Compilers
Learning to write a compiler
Constructing a simple interpreter
...
And similar topics (from the same search):
Bootstrapping a language
How much of the compiler should we know?
Writing a compiler in its own language
...
Edit: I know the stackoverflow related question search isn't what we'd like it to be, but
did we really need the nth iteration of this topic? Meh!
The first tool I would recommend is the Dragon Book. That is the reference for building compilers. Designing a language is no easy task, implementing it is even more difficult. The dragon book helps there. The book even reference to the standard unix tools lex and yacc. The gnu equivalent tools are called flex and bison. They both generate lexer and parser. There exist also more modern tools for generating lexer and parser, e.g. for java there are ANTLR (I also remember javacc and CUP, but I used myself only ANTLR). The fact that ANTLR combines parser and lexer and that eclipse plugin is availabe make it very comfortable to use. But to compare them, the type of parser you need, and know for what you need them, you should read the Dragon book. There are also other things you have to consider, like runtime environment, programming paradigm, ....
If you have already certain design ideas and need help for a certain step or detail the anwsers could be more helpful.
ANTLR is a very nice parser generator written in Java. There's a terrific book available, too.
I like Flex (Fast Lex) [Lexical scanner]
and Bison (A Hairy Yacc) [Yet another compiler compiler]
Both are free and available on all *NIX installations. For Windows just install cygwin.
But I old school.
By using these tools you can also find the lex rules and yacc gramers for a lot of popular languages on the internet. Thus providing you with a quick way to get up and running and then you can customize the grammers as you go.
Example: Arithmetic expression handling [order of precedence etc is a done to death problem] you can quickly get the grammer for this from the web.
An alternative to think about is to write a front-end extension to GCC.
Non Trivial but if you want a compiled language it saves a lot of work in the code generation section (you will still need to know love and understand flex/bison).
I never finished the complete language, I had used rply and llvmlite implements a simple foxbase language, in https://github.com/acekingke/foxbase_compiler
so if you want use python, rply or llvmlite is helpful.
if you want use golang, goyacc maybe useful. But you should write a lexical analyzer by hard coding by hand. Or you can use https://github.com/acekingke/lexergo to simplify it.