Basic example of closure with a heavy logic

example-basic-closure.rs

 let result = |word| {
        
        // Heavy logic //
        let fname = "text_to_find.txt";
        // Contents of file
        let contents = fs::read_to_string(fname).expect("Something went wrong reading the file");
        // Search a word into file's content
        match contents.find(word) {
            Some(v) => v as u64, 
            None => 0
        }

}