How to parse a string to find key-value pairs in it

Question

While searching mail in Google, we use the sytax like

from:devcoder hasattachments:true mySearchString on:11-aug

or

mySearchString from:devcoder on:11-aug anotherSearchKeyword

After parsing, I should get the keyvalue pair such as (from, devcoder), (on, 11-aug). What is the best way to implement this parsing in c#.

Answer 1

To Linq-ify Jason's answer:

string s = "from:devcoder hasattachments:true mySearchString on:11-aug";

var keyValuePairs = s.Split(' ')
    .Select(x => x.Split(':'))
    .Where(x => x.Length == 2)
    .ToDictionary(x => x.First(), x => x.Last());

Answer 2

Split by space, then for each component of the split, split it by :. Then proceed accordingly. Roughly:

string s = "from:devcoder hasattachments:true mySearchString on:11-aug";
var components = s.Split(' ');
var blocks = components.Select(component => component.Split(':'));
foreach(var block in blocks) {
    if(block.Length == 1) {
        Console.WriteLine("Found {0}", block[0]);
    }
    else {
        Console.WriteLine(
            "Found key-value pair key = {0}, value = {1}",
            block[0],
            block[1]
        );
    }
}

Output:

Found key-value pair key = from, value = devcoder
Found key-value pair key = hasattachments, value = true
Found mySearchString
Found key-value pair key = on, value = 11-aug

Output from your second string:

Found mySearchString
Found key-value pair key = from, value = devcoder
Found key-value pair key = on, value = 11-aug
Found anotherSearchKeyword