Rico Felix

And yet again, the previous instance had crashed and a new one is up at a new address

For those who would like to try... Its up again at a new address  

[UPDATE]

Thanks to all who tried... I managed to crash it myself, so the server is temporarily out of service...

Will notify when ready to try again  

Hi all,

Haven't been here a while due to work on a new OS described briefly in the title...

What I'm here for is to kindly ask members here if you'll can try to crash a web-server appliance that my team members and I created using the OS at Acorn Web Appliance...

To provide a little insight into why such a method is available follows:

Data representation in an electronic computing system is solely based on interpretation...

All a computer does is store and manipulate sequences of (for the sake of simplicity) patterns...

It is up to the user to decide what the pattern represents...

Now using established conventions, we have the following:

0011_0000 <- bit pattern to represent a character '0'
0000_0000 <- bit pattern to represent the numeric value 0

From this we can see that those patterns are completely different, but from a high level of viewing information on a screen, one can be misguided as viewing the character '0' and the numeric value 0 as being the same when the computer understands differently...

So in order to perform correct manipulations on our data, an environment provides facilities for making the representations transparent to the user...

Going back to your specific question, a String is simply a sequence of characters which will have different patterns from an actual numeric value even though the String may appear to represent a numeric value...

In order to perform numeric operations on such a data type you must convert it into a representation that the computer can understand to perform such an operation, hence the reason for Integer.parseInt()

For the C Programming Language I would probably recommend Mastering Algorithms with C

Hi ranchers,

For those of you who probably haven't heard, the Standard C++ Foundation has posted a project on github for outlining guidelines and rules for the C++ Programming Language...

The aim of the project is to acquire and establish a set of best practices and advice for programming in the language using modern techniques...

For those of you who are experienced and interested can look at the project and give valuable input to help shape it for the entire community...

Seeing that you mentioned the word class I assume you are programming in the C++ Programming Language...

The only difference in this language between a class and a struct is the default visibility of members...

If you know how to use a class then you know how to use a struct... Just switch the default member visibility options...

Basically what is happening in your code that is causing the error is that, in your header file it declares and incomplete type therefore you are unable to use it until you provide a definition for the object that the compiler can use to create an object...

There is a difference with holding the address to an incomplete type and trying to create an object from an incomplete type...

If you were to change you main file to the following it will compile:
//in Main.cpp #include "Date.h" int main() { Date* date; }

Simply because the compiler knows how big a pointer is... Remember that a pointer is simply an address in memory and the type only says how to interpret the memory at that location...

Even if you are allowed to declare a pointer to an incomplete type, it is still unusable because there is no notion defined about what the type is capable of representing... In other words there is no information describing how big the object is and how to partition the memory to represent its individual fields...

For your code to work as is you will have to move the entire definition of the structure into the header file...

You can think of header files as interfaces to modules which you use to import functionality into your own code...

It typically contain function declarations which are used to operate on some structure that represent a concept...

It may also contain platform configuration details and system-wide values...

One useful way to use header files is to emulate OOP abstraction as follows:

This file will be used by you which you include in your application to work with a person object
/* @file person.h * * Interface file for using a person object */ #ifndef PERSON_HPP #define PERSON_HPP typedef struct person_t Person; // Hide the representation of a person /* * Function to get an object from the system that represents a person * by name and age */ Person* new_Person(const char* name, const int age); /* * Function to return a retrieved person object back to the system */ void delete_Person(Person* person_object); /* * Function to print the description of the person object */ void person_Description(const Person* person_object); #endif

This file will be distributed as a binary object file for linking into your application... Its details are unknown to you
/* @file person.c * * Hidden implementation details not seen by the user */ #include <stdio.h> #include <string.h> #include <stdlib.h> #include <assert.h> #include "person.h" struct person_t { char* name; int age; }; Person* new_Person(const char* name, const int age) { assert(name); size_t name_length = strlen(name); void* memory = malloc(name_length + 1); assert(memory); strncpy(memory, name, name_length); struct person_t* new_person = malloc(sizeof(struct person_t)); if (!new_person) { free(memory); fprintf(stderr, "%s\n", "Not enough memory"); exit(-1); } new_person->name = memory; new_person->age = age; return new_person; } void delete_Person(Person* person_object) { assert(person_object); free(person_object->name); free(person_object); person_object = NULL; } void person_Description(const Person* person_object) { assert(person_object); printf("Name: %s Age: %d\n", person_object->name, person_object->age); }

This is your application file which uses the interface file for working with person objects in your application...
/* @file application.c */ #include "person.h" int main(void) { Person* eric_mitchell = new_Person("Eric Mitchell", 17); person_Description(eric_mitchell); delete_Person(eric_mitchell); }

As you can see, details of how stuff work to use a person in your application is just a matter of including the header file (interface) and using its published services...

You can think of it as an architectural design... Since all objects implicitly inherent from the Object class that has a toString implementation, they will exhibit that default implementation unless overridden... Therefore the CharSequence interface is simply stating that if you want to be my representative, you must override the default toString method and this is how you must do it...

I enjoyed the patterns for filtering file content with minimal lines of code... Makes imperative programming seem like an ancient art-form..

Here is a link from cppreference.com that may be of interest to you...

The course was interesting... I actually learnt something...

The certificate doesn't look that impressive though...

Why not use one label and reset the text on the event...