parsing multi sections of a text file C#

Question

First let me start by thanking you all for being part of this site, I have already gained so much helpful information from it. including some basic parsing of text files in to Arrays, but i now want to go a step further.

I have a text file that looks some thing like this

Start Section 1 - foods

apple  
bannana  
pear   
pineapple  
orange  

end section 1

Start section 2 - animals

dog  
cat  
horse  
cow  

end section 2 

what I want to do is using a single read of the file copy the data from section 1 in to an array called "foods" and section 2 in to and array called "animals"

now I can get it to work by using a new loop for each section, closing and reopening the file each time, looping till I find the section I want and creating the array.

But I was thinking there must be a way to read each section in to a separate array in one go saving time.

so my current code is

List<string> typel = new List<string>();  

using (StreamReader reader = new StreamReader("types.txt")) // opens file using streamreader
        {

            string line; // reads line by line in to varible "line"
            while ((line = reader.ReadLine()) != null) // loops untill it reaches an empty line
            {
                typel.Add(line); // adds the line to the list varible "typel"
                               }

        }

        Console.WriteLine(typel[1]);  // test to see if list is beeing incremented
        string[] type = typel.ToArray(); //converts the list to a true array 
        Console.WriteLine(type.Length); // returns the number of elements of the array created. 

which is for a simple text file with no sections just list of values, using list seemed a good way to deal with unknown lengths of arrays.

I was also wondering how to deal with the first value.

for example if i do

while ((line = reader.ReadLine()) != Start Section 1 - foods)  
{  
}  
while ((line = reader.ReadLine()) != end Section 1)   
{  
foods.Add(line);  
}  
...  
....

I end up with the "start Section 1 - foods" as one of the array elements. I can remove it with code but is there an easy way to avoid this so only the list items get populated?

Cheers and once again thanks for all the help. Its great to be getting back in to programming after many many years.

Aaron

Answer 1

Reading the lines is not the issue, see System.IO.ReadAllLines(fileName) and its siblings.

What you need is a (very simple) interpreter:

// totally untested
Dictionary<string, List<string>> sections = new Dictionary<string, List<string>>();
List<string> section = null;

foreach(string line in GetLines())
{
   if (IsSectionStart(line))
   {
      string name = GetSectionName(line);
      section = new List<string>();
      sections.Add(name, section);
   }
   else if (IsSectionEnd(line))
   {          
      section = null;  // invite exception when we're lost
   }
   else
   {
      section.Add(line);
   }
}


...
List<string> foods = sections ["foods"];