About code. Mostly on C++
So far, C#, unlike C++, did not support optional arguments. For instance, suppose you need a function to print log a message, that can add a new line or not after writing the message. Most of the times you want a new line, so you don’t want to specify that for most of the calls. … Read more
The new C++0x standard provides support for type inference. The auto keyword that was doing nothing in C++ was given a new meaning: a placeholder for a type inferred by the compiler. For those familiar with C#’s var keyword, this is basically the same. Here is a comparison between auto in C++ and var in … Read more
In my previous post I have provided some background theory for evaluating expressions with abstract syntax trees. As I was mentioning, the first step towards this goal is to parse the expression, make sure it is correct syntactically. This is what I’ll show you in this post. Having the grammar defined, we’ll make one function … Read more
This is the record number of error I ever got in a project: 50917. After compiling that VC# project (with T4), Visual Studio 2008 was a little bit overwhelmed. It started to report out of memory errors and failed to build after fixing the error. A restart was, of course, the cure.
FParsec is an F# adaptation of Parsec, a free monadic parser combinator library for Haskell. It can parse context-sensitive, infinite look-ahead grammars, has complete support for unicode input and large files (> 4 GB) and produces excellent error messages. You can download and install it from the above link. To use it in an application, … Read more
A few days ago Anders Hejlsberg delivered a presentation about the Future of C# at the Professional Developers Conveference 2008. He focused on the new things that will be available in C# 4.0: dynamic typed objects optional and named parameters improved COM interoperability co- and contra-variance The recording of the presentation is available on Channel9 … Read more
A very old unsolved problem in numbers theory, known as Goldbach’s conjecture, says that any even number greater than 5 can be written as the sum of 2 prime numbers. It hasn’t been solver yet, not I will try to solve it. But I decided to write some F# code to display all the possibilities … Read more
Microsoft released today the first service packs for Visual Studio 2008 and .NET Framework 3.5. For the time being they are available to download to MSDN subscribers. Visual Studio 2008 SP1 contains: Improved WPF designers SQL Server 2008 support ADO.NET Entity Designer Visual Basic and Visual C++ components and tools (including an MFC-based Office 2007 … Read more
I recently found an interesting problem on the web, about reducing words, letter by letter until only one letter remains. Here is a formal definition: We define word reduction as removing a single letter from a word while leaving the remaining letters in their original order so that the resulting sequence of characters is also … Read more
The Game of Life is a cellular automaton devised by the John Horton Conway in 1970. It is the best-known example of a cellular automaton. It consists of a collection of cells which, based on a few mathematical rules, can live, die or multiply. Depending on the initial conditions, the cells form various patterns throughout … Read more