LepEx

2004-01-23T03:11:00.000+02:00

Recusive properties

Look close!

public int CurrentLine
{
  get
  {
    return GetLineFromIndex(caretindex);
  }
  set
  {
    if (value < 0)
    {
      CurrentLine = 0;
    }
    else if (value < Count)
    {
      int ci = LineColumnIndex;
      CaretIndex = GetCaretIndexFromLine(value);
      LineColumnIndex = ci;
    }
    else
    {
      CurrentLine = Count - 1;
    }
  }
}

2003-12-13T02:57:00.000+02:00

Top secret Sneak preview

2003-11-30T16:12:00.000+02:00

A glimpse of things to come

I normally dont do UI's but this came to mind. A decent code highlighter, with dynamic lexer/parser input and many goodies normally found in commercial IDE's.

2003-11-29T02:19:00.000+02:00

Abusing C#


int c = file.ReadByte();
switch (c)
{
	case -1:
		Console.WriteLine("EOF");
		break;
	case '\n':
		curline++;
		curcol = 1;
		goto case -2;
	case -2: // i will be shot
		feed.Append((char) c);
		break;
	default:
		curcol++;
		goto case -2;
}

2003-11-21T22:34:00.000+02:00

Hooray, it's holiday

Now its time to enjoy those things you never have time for. I love pretty code.

2003-10-26T13:31:00.000+02:00

Monthly Lobster awards

I have decided to make a monthly award for certain developers that can be described as lobsters (think Zoidberg right about now).

Seeing this is the 1st ceremony I have decided to name a few to get things going.

1. Lutz Roeder - does his email even work? does he even read feedback? Not much I guess! And the time I did get a response, he put all the ideas down... see Reflector for a more painfull experience.

2. Werner "I cant say much, I'm under a NDA" Moise - well, well, well, your news is mostly old. You keep argueing without checking your facts. And it is not grammatically correct to start every sentence with 'I'. And repeating your self consistantly makes you look like an idiot. All of us can read.

2003-10-26T13:14:00.000+02:00

Gay C# error messages

Overloaded shift operator must have the type of the first operand be the containing type, and the type of the second operand must be int.

Enough said...

2003-10-13T23:42:00.000+02:00

Slow times

I have started a new personal project called Xacc. More info can be found at xacc.sourceforge.net. Comments welcome.

2003-08-30T19:02:00.000+02:00

GCC beats MS VC7.1 pants off

I have just finished the lexer/parser part of my project due on Monday. I thought some benchmarking would be nice. What I didnt realize was the advantage GCC has over VC in a C environment. The implementation only makes use of some of the core CRT libraries.

2003-08-26T23:03:00.000+02:00

My latest invention/contraption/experiment

2003-08-24T21:49:00.000+02:00

#dev 0.96 - TextEditor still junk

Compare this to what I would like to see (below) from a quality perspective. Also, it still takes the memory of a small country (60-80mb) , and I swear I saw the street lites dim when I loaded it.

2003-08-24T05:49:00.000+02:00

When things go wrong...

2003-08-23T18:54:00.000+02:00

Dont you love C compiler error messages?

Here's the Error OTD:

error C2064: term does not evaluate to a function taking 26386312 arguments

2003-08-23T12:42:00.000+02:00

Lexical analysis speed

Tokens a second?

Lines a second?

Here is some performance specs for a toy Oberon language (given to us), consisting of 39 keywords and operators, 16-bit numbers, variable length variable names, and nested commenting. Test file is 2.4MB is size and is lexically correct.

Timer(Start) SCAN (context free)
Timer(Stop ) 30294 ms   24353 tokens per second
Lines per second: 6608 (200179 lines)
Total tokens read: 737760

(on an AMD 1600+, 640mb PC133 RAM, statically linked, release mode)

How can one measure the acceptability of ones implementation?

2003-08-23T12:11:00.000+02:00

Here comes C

OK. I like C, but learning programming from an OO perspective has killed my ability to write effective C code. O well, easy come, easy go.

2003-07-28T20:50:00.000+02:00

Lame C# compiler error of the day

Compiler Error CS0553'conversion routine' : user defined conversion to/from base class
User-defined conversions to values of a base class are not allowed; you do not need such an operator.
The following sample generates CS0553:

// CS0553.cs
namespace x
{
   public class ii
   {
   }

   public class a : ii
   {
      // delete the conversion routine to resolve CS0553
      public static implicit operator ii(a aa) // CS0553
      {
         return new ii();
      }

      public static void Main()
      {
      }
   }
}

But now I need one, what now?

2003-07-28T20:11:00.000+02:00

Problem solved. Solution: RTFM

From MSDN (dope):

Use IsNaN to determine whether a value is not a number. It is not possible to determine whether a value is not a number by comparing it to another value equal to NaN.

2003-07-26T16:32:00.000+02:00

OK, can someone please explain to me the meaning of this?

2003-07-23T00:07:00.000+02:00

Something new

Hmm, I really need to stick to one thing, but I just had an inspiration today. Nice feeling when you get 600+ productive lines of code in an afternoon/evening. The following image (GDI+) is rendered from the following code:

Variable x = "x";
Function f = new Function(x, ((x-2)^2) - 2*x);
Function g = new Function(x, (2/x+(3^x)));
Function h = new Function(x, (((x)/3)^3) + ((x/2)^2));
Function i = new Function(x, x);
Function j = new Function(x, -x);
Function k = new Function(x, 3 * new UserExpression(x/2, typeof(Math),"Sin"));
Function l = new Function(x, 2 * new UserExpression(0.5/x, typeof(Math),"Cos"));
Function m = new Function(x, (new UserExpression(x, typeof(Math),"Exp") - 6)/2);

All these functions gets added to a Graph object that handle the drawing for a GraphControl, all with designer support and no flickering. Colors are assigned using a hash thingamagik.

int hash = f.GetHashCode();
gp.Color = Color.FromArgb(hash*61%256,hash*37%256,hash*53%256);

I dont know much of hashing, but with a bit of trial and error this seems to create the best variations.

2003-07-04T21:57:00.000+02:00

Hide and Seek champion fails at 13 months

Ah well, look what I found today. I little "hidden" button in the text editor. At first I thought it was a graphical glitch as VS.NET has started looking all misaligned since I have turned on ClearType font smoothing. This something I have been looking for a year. Well here it is!

2003-07-03T20:27:00.000+02:00

Be thankful you dont live in a 3rd world country

This is what us lucky ones has to bare with. Obviously this clown has not even attempted Networking 101 else he would know the difference between bandwidth and latency (did I mention I have ISDN, so pings of 30ms are expected). Here follows the "conversation":


hello,

Please be informed that by the nature of your querie this seems to be a
dialup issue.I therefore regret to inform you that there is no
guaranteed bandwith for dialup.The network seems to be busy and therefore
you are experiancing latency.I have check with our network operations
centre and they have confirmed this.

Thanks

Wayne D'sa

Customer Service Centre

UUNET SA

08600 UUNET (0860088638)

Email :support@uunet.co.za


-----Original Message-----
From: leppie
Sent: Wednesday, July 02, 2003 10:27 PM
To: support@ataris.co.za
Subject: Very high latency

Hi Support

|------------------------------------------------------------------------------------------|
|                       Host              -   %  | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
|                             192.168.0.1 -   90 | 1002 |  109 |    0 |     0|   10 |    0 |
|                 lo1.nas1.cpt1.alter.net -    1 | 1002 |  999 |   30 |  221 |  741 |  220 |
|                 e1-0.dr2.cpt1.alter.net -    8 | 1001 |  929 |   30 |  213 |  651 |  200 |
|                vlan9.hr1.cpt1.alter.net -    8 | 1001 |  927 |   30 |  212 |  601 |  190 |
|                rl1.phantom.ataris.co.za -    6 | 1001 |  942 |   30 |  216 |  681 |  170 |
|________________________________________________|______|______|______|______|______|______|

I think that tells the story. What is going on with the lines?

Regards

leppie

2003-07-03T19:58:00.000+02:00

Nothin to see here! Move along people!

2003-07-01T06:18:00.000+02:00

Major Tip of the Day

This will help you manage all those brushes and pens you so relentlessly create withou disposing of them correctly. YES YOU!!!


public class GDIBuffer
{
  static Hashtable pens = new Hashtable();
  static Hashtable brushes = new Hashtable();

  public static Brush GetBrush(Color color)
  {
    if (!brushes.Contains(color))
        brushes.Add(color, new SolidBrush(color));
    return brushes[color] as Brush;
  }

  public static Pen GetPen(Color color)
  {
    if (!pens.Contains(color))
      pens.Add(color, new Pen(color));
    return pens[color] as Pen;
  }

  public static Pen GetPen(Brush brush)
  {
    if (!pens.Contains(brush))
      pens.Add( brush, new Pen(brush));
    return pens[brush] as Pen;
  }

  public static Pen GetPen(Brush brush, int width)
  {
    Tuple t = new Tuple();
    t.left = brush;
    t.right = width;

    if (!pens.Contains(t))
      pens.Add( t, new Pen(brush, width));
    return pens[t] as Pen;
  }

  struct Tuple
  {
    public object left;
    public object right;
  }
}

2003-06-07T22:06:00.000+02:00

IT'S ALIVE!

After running thru endless trace logs today, the parsing engine is working 100%. A simple C# file of 175 lines makes a trace log of almost 27 000 lines. Luckily the Total Commanders Lister viewer is lightning fast and makes finding something visually a painless experience. Next up, I'll add some profiling code, to assist in EBNF source file creation. I'm still wondering whether to make a AST or FileMap. Anyways, back to work!

2003-06-07T05:58:00.000+02:00

Success!

The parser and logic engine has now been completed in both AsmL and C#. I currently test this to C# definition file I have managed to put together. Currently the AsmL code is only 270 lines and the C# code around 550 lines including some comments. Next step is to build either a "syntax" tree or a file map, but I am still a bit skeptical which one to use. I have even though of XML as a possiblity, perhaps a DataSet? We will have to wait and see, I first have run some more tests.

2003-06-05T05:34:00.000+02:00

Parser Update

I have been fooling myself in a sense. I was reinventing the wheel. But is this so bad when the wheel is in fact a simplification of RegEx. When I started doing this 2 weeks ago, I could barely write a line of RegEx. Now suddenly, I have learnt a simplification of Regex without touching RegEx and it now makes sense to me. Almost like the Neo oke from the Matrix. Even things that I never understood like DTD and XSL, suddenly made sense too. All to crown this all, I wrote 2 exams today as well.

Anyways, I have now decided after playing a bit more with AsmL to build a simple RegEx framework for AsmL. A parser should be a natural following to that; isnt that what RegEx is good for? LepEx seems an appropiate name for this too :)

Here is a little snippet:

structure Group extends Machine

  case Repeater

    count as Integer = 0

  case Optional

    actual as Boolean = false

  case Iterator

    count as Integer = 0



  inner as Machines

  grouptype as GroupType = And



  GroupFormat() as (Format, Format)

    match me

      Repeater: return (LRep, RRep)

      Optional: return (LOpt, ROpt)

      Group   : return (LGrp, RGrp)



  SepFormat() as Format

    match grouptype

      And: return AndL

      Or:  return OrL

      Not: return NotL



  override ToFormat() as Format

    (l,r) = GroupFormat()

    return Format.List(l, SepFormat(), r, [ToFormat(i) | i in inner])

2003-06-01T13:07:00.000+02:00

AsmL update

I have managed to rewrite to logic engine in AsmL and reduced it size from roughly 1000 lines to about 100 in AsmL. Also, much less code generation is needed. Currently, I'm trying to a simplifying algorhytm to get rid of unneccesary grouping constructs. As the syntax of AsmL is still a bit new to me, I have tried doing this in C# rather. Again the AsmL solution is much simpler, but I am have some problems assigning the final bit. C# has proved to long in the tooth with endless casting.

2003-05-31T18:52:00.000+02:00

TIP of the day

Never, ever, ever mess around with things when you dont know the outcome. Today, I messed around with .NET security permission. Needless to say, it screwed up .NET to such an extent that it could not even be repaired. An uninstall/reinstall was required, but that luckily does not take too long.

2003-05-31T01:52:00.000+02:00

First Post

A week ago work was started on a parser generator for .NET . A week later, and I'm back to the drawing boards. This time I looking at a newly found language called AsmL. Abstract State Machine Language.