Posts

A generic database class

This is a class I use frequently for running SQL commands / queries: public   class   Database  :  IDatabase {      public   Database ( DatabaseConfiguration   config )     {          this . config   =   config ;     }      public   object [][]  RunQuery ( string   query ,  params   object []  args )     {          using  ( var   con   =   Connect ())          using  ( var   cmd   =   Prepare ( con ,  query ,  args ))              return   cmd . ExecuteReader () . Pipe ( ReadData );     }      public   void   RunNonQuery ( string   command ,  params   object []  args )     {          using  ( var   con   =   Connect ())          using  ( var   cmd   =   Prepare ( con ,  command ,  args ))              cmd . ExecuteNonQuery ();     }      //      private   static   readonly   ITableReader   TABLE_READER   =   new   TableReader ();      private   readonly   DatabaseConfiguration   config ;      private   SqlConnection   Connect ()  =>          new   SqlConnection ( co
Post a Comment
Read more

The early bird catches the worm

Here are three reasons to do things later rather than earlier: You will know more. You will usually be richer and thus can buy some help (at least for part of the task). You might be dead and therefore no longer care about the task :)
Post a Comment
Read more

On Dependency Injection

I just read an article about eliminating dependencies whose basic thesis is that instead of having a class that depends on something that can give you a value, just depend on that value directly. His example (which you can read more fully in the article) is that instead of having public InvoiceGenerator(IConfigurationReader configurationReader) { _configurationReader = configurationReader; } and later on calling var watermarkText = _configurationReader.Get<string>("invoiceWatermarkText"); if (!String.IsNullOrEmpty(watermarkText)) to get the text we need, just request the text directly: public Invoice GenerateInvoice(string watermarkText) { if (!String.IsNullOrEmpty(watermarkText)) There are two obvious problems with this, which you will hit extremely quickly in real code. One of them, pointed out by a comment by LeszekP, is that most of the time you will require more than a single value from an interface.
Post a Comment
Read more

My views on blockchain / bitcoin

Going from abstract to concrete: Private currency: good. I would love to have lots of them, just as I love both gold and silver. Blockchain: not so good, more of a solution in search of a problem. The only advantage it has compared to an append-only database is decentralization… and I don't see a need for that. I would much rather have many private currencies. Also, in practice most coins are actually centralized, or at least a very small oligarchy. Bitcoin: nah. Really bad. Incredibly slow to initialize, slow transactions, easy to control by a sustained state-level effort, very low cap on number of transactions per second, plenty of bugs, hard-forks which means the code is actually controlled by a small group (which in turn means that I can't trust that the currency itself is decentralized)… nah. In conclusion, I like the initiative, and I'm 100% behind the idea that we need to separate states and money, but we're nowhere near yet.
2 comments
Read more

The problem with null

The problem with null is that it pretends to be an object of a given type, without actually having that type. For example (C# code - ignore the uselessness of the GetName method): string GetName(Customer customer) { // I got a customer object, I can access the Name property return customer.Name; } var x = func(null); // <-- not a real Customer object so we have a run-time error The proper way to solve this is by using the Option (aka Maybe) monad; for an example using the Functional.Maybe NuGet package: string GetName(Maybe<Customer> customer) { // I don't actually have a Customer object, I have a Maybe<Customer> // I need to treat it carefully return customer.Select(it => it.Name).OrElse("Missing"); } var x = func(null); // compiler error, because Maybe<> doesn't allow null as a value var x = func(Maybe<Customer>.Nothing); // the customer is missing but the call will not crash Using the Opt
Post a Comment
Read more

FanFiction

FanFiction Phrase from a book I'm reading: I was bitten by a radioactive Jedi as a child. The Havoc side of the Force
Post a Comment
Read more

Fan-fiction recommendations

I posted this to HN and I realized it might be useful for other people. If at least one person who wasn't aware of fan-fiction discovers it as a result, this has served its purpose. For Buffy fans, TTH has a huge number of stories, both in-universe and crossovers with other worlds. Speakertocustomers , Becuzitswrong , Cordyfan , DianeCastle and Hotpoint are a few of my favorite authors. Hotpoint's crossover between X-COM and SG-1 is absolutely amazing. For other worlds, FF , SB , SV and AO3 are the most well-known sites for fanfiction. One of my favorite stories is Taylor Varga . What I normally do is I download the stories in the .mobi format - TTH and AO3 have that feature in the site, and for the others you can use the FanFicFare plugin for Calibre - and then upload them to my Kindle. This allows me to read in bed, which is bad for my sleep but I like it :)
Post a Comment
Read more