Building a Search Engine .. using Delphi 7

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December 28th, 2012, 05:06 PM

iTechnical

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Building a Search Engine .. using Delphi 7

Greeting Everybody
well, I'm studying ITC in last level of BS..I need many many helps in my graduate project.
it will be Search Engine , using data structures and text Files that's store in Hard disk.I will build and programmed by using Delphi language..
I already started to learn it before 2 weeks ago , but I need strongly help to achieve my tasks .
I wish that you are help me !

Hint: I will keep this page for my Questions..

Thanks

December 28th, 2012, 05:15 PM

iTechnical

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read the text of file

The first attempt to read the text of file and display the text in Memo:

Code:

Var
myFile:TextFile;
text:string;

procedure TForm1.ReadButtonClick(Sender: TObject);

begin
AssignFile(myFile, 'superComputer.txt');
Reset(myFile);
While not eof(myFile) Do
Readln(myFile,text);
Memo1.Lines.LoadFromFile('superComputer.txt');
closeFile(myFile);
end;

December 28th, 2012, 05:18 PM

iTechnical

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Question (1)

How to extract each word from Text of File and store in Array without spaces?

December 28th, 2012, 05:36 PM

Scorpions4ever

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Quote:

Originally Posted by iTechnical

The first attempt to read the text of file and display the text in Memo:

Code:

Var
myFile:TextFile;
text:string;

procedure TForm1.ReadButtonClick(Sender: TObject);

begin
AssignFile(myFile, 'superComputer.txt');
Reset(myFile);
While not eof(myFile) Do
Readln(myFile,text);
Memo1.Lines.LoadFromFile('superComputer.txt');
closeFile(myFile);
end;

Do you realize that most of that code you wrote does nothing useful at all? You could do the same thing with only one line of code

Code:

procedure TForm1.ReadButtonClick(Sender: TObject);
begin
    Memo1.Lines.LoadFromFile('superComputer.txt');
end;

That's all there is to it.

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December 28th, 2012, 05:48 PM

Scorpions4ever

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Quote:

Originally Posted by iTechnical

How to extract each word from Text of File and store in Array without spaces?

Code:

var 
    words : TStringList;
    MyString : String;
    idx: integer;
begin
    MyString := "This is a test";
    words := TStringList.Create;
    // words.Delimiter := ' '; // This is the default. Uncomment and change to another character if you have a different delimiter.
    words.DelimitedText := MyString;

    // String should now be split by spaces
    for idx := 0 to words.count - 1 do
    begin
        ShowMessage(words[idx]);
    end;

    words.Free;
end;

December 28th, 2012, 06:33 PM

iTechnical

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Quote:

Originally Posted by Scorpions4ever

Do you realize that most of that code you wrote does nothing useful at all? You could do the same thing with only one line of code

Code:

procedure TForm1.ReadButtonClick(Sender: TObject);
begin
    Memo1.Lines.LoadFromFile('superComputer.txt');
end;

That's all there is to it.

Thank you Scorpions4ever

But it was evaluation for me...
How do I open the file and read the text inside it .

December 28th, 2012, 07:14 PM

iTechnical

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Quote:

Originally Posted by Scorpions4ever

Code:

var 
    words : TStringList;
    MyString : String;
    idx: integer;
begin
    MyString := "This is a test";
    words := TStringList.Create;
    // words.Delimiter := ' '; // This is the default. Uncomment and change to another character if you have a different delimiter.
    words.DelimitedText := MyString;

    // String should now be split by spaces
    for idx := 0 to words.count - 1 do
    begin
        ShowMessage(words[idx]);
    end;

    words.Free;
end;

it's working perfectly .

December 28th, 2012, 07:17 PM

iTechnical

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but my Supervisor asked me to defined an Array to store each word ! I'm still trying
This is part of my attempt ...

Code:

const size=1000;
 var
 myFile:TextFile; 
text:string; 
I:integer; 
MyArray:Array [1..size] of string;   
 begin 
AssignFile(myFile, 'concepts.txt'); 
Reset(myFile); 
repeat
 Readln(MyFile,text); 
// here should be write a condition to check a if the word between 2 spaces then take it and store in Array but I don't know HOW ?  :(


// if the condition is True .. do this : 
Begin 
MyArray [I] := text; 
I := I+1; 
Until eof(MyFile); 
End;

What do you think ??

December 29th, 2012, 12:11 AM

Luthfi

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There are flaws in your definition of word. If you only capture those between two spaces, then you will fail to capture word at the the start of the string, word at the end of the string, and words followed by punctuations.

Anyway, it is better if you "walk" the source string. Use two integer variables to know the starting and end position to extract a word once one detected.

Something like below (warning, not completed code, more like pseudocode).

Code:

var
  T: string;
  i, j: Integer;
begin
  i := 1;
  for j := 1 to Length(SourceStr) do
  begin
    if SourceStr[j] is end of a word then
    begin
      T := Copy(ASourceStr, i, j-i);
      Add T to your array;
    end;
  end;
end;

For the array, you can use dynamic array. Declare it something like this.

Code:

var
  vArray: array of string;

Note that using dynamic array you need to make sure it has sufficient size. You can alter its size with SetLength, similar like string. And dynamic arrays always start from 0.

Building a Search Engine .. using Delphi 7

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