Do any computer languages not use a stack? [closed] - data-structures

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Do any computer languages not use a stack data structure to keep track of execution progress?
Or is the use of this data structure an emergent requirement stemming from something inherent to most computer languages or turing machines?

With a traditional "C-style" stack, certain language features are difficult or impossible to implement. For example, closures can't easily be implemented with a traditional stack because closures require a pointer to an old activation record to work correctly and that memory is automatically reclaimed in a C-style stack. As another example, generators and coroutines need their own memory to store local variables and relative offset information and therefore can't easily be implemented if you use a standard stack implementation.
Hope this helps!

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Parallel computing: from theory to practice [closed]

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I studied how to optimize algorithms for multiprocessor systems. Now I would understand in main lines how these algorithms can be transformed into code.
I know that exist some libraries MPI based that helps the developement of software portable to different type of systems, but is right the word "portable" that makes me confused: how the program can be authomatically adapted to an arbitrary number of processors at runtime, since this is an option of mpirun? How the software can decide the proper topology (mesh, hypercube, tree, ring, etc)? The programmer can specify the preferred topology through MPI?
you start the application with a fixed number of cores. Thus, you cannot automatically adapted to an arbitrary number of processors at runtime.
You can tune your software to the topology of your cluster. This is really advanced and for sure not portable. It only makes sense if you have a fixed cluster and are striving for the last bit of performance.
Best regards, Georg

Advanced Rudimentary Computing? [closed]

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Lets say that my definition of 'rudimentary programming' refers to the fundamental tools employed for a computer to perform a task.
Considering programming rudiments, the learning spectrum usually looks something like this:
Variables, data types and variable memory
Arrays/Lists and their manipulation
Looping and conditionals
Functions
Classes
Multi threading/processing
Streams (hard-disk and web)
My question is, have I missed any of the major rudiments? Is there a 'next' to the spectrum that still eludes me?
I think you missed the most important one: algorithms. Understanding the complexity, know the situation to use them, why use them and more important, how to implement them.
I'm pretty sure that you already know a lot about algorithms but if you think that your tool-knowledge (aka the programming languages) are good enough, you should start focus, more, on the algorithms.
A great book to start is: Introduction to Algorithms, from Thomas H. Cormen

Are applications such as image processing naturally slow in Scheme for lacking a random-access data-structure? [closed]

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Scheme lists are slow for random access, which is a common operation in many applications such as image processing. Does this make it naturally handicapped for that kind of application?
If performance is a concern, then you should definitely consider using fixed-access-time structures. Fortunately, Scheme has lots of these, too. The "vector" is the simplest one; it's a close match to what most languages call an "array".

Algorithm reference [closed]

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This is a trivial question - but something I always miss in the day-to-day programming.
Is there a gook lookup reference available for the common algorithms that we usually face in our everyday programming - sorting,sequences,graphs.
The emphasis is more on the applicability and pseudocode ,rather than the mathematical proofs(which I find is what books tend to stress on).
The idea is to keep a ready reference,as and when we need to resort to one of these algorithms into our respective development project and languages.
Dictionary of Algorithms and Data Structures
How about this?
List of algorithms#Wikipedia

How to measure the size of a Ruby object? [closed]

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I'm having Memcache problems and I was wondering what is the best way to know how big the objects I create are.
The only solution I have is to put them into Memcache which display their size in bytes (by the way, can I customize Memcache's output? I want readable kilobytes…).
Thank you,
Kevin
The excellent Eigenclass blog had an interesting article on that once:
http://web.archive.org/web/20120126022146/http://eigenclass.org/R2/writings/object-size-ruby-ocaml
There also was a good discussion on ruby-talk, which led to some code by Robert Klemme (Ruby Best Practices):
http://www.ruby-forum.com/topic/156648
http://www.pastie.org/217131
Plugging the values from the first article into the script might get you started and is probably quite educational.
You could also check out memprof, though it's more about object references and finding memory leaks than actual sizes:
http://github.com/ice799/memprof

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