Example Program
Iterator Basics
Simple iterator functions.
A tutorial about the use of iterators.
1#include <iostream>
2#include <seqan/sequence.h>
3#include <seqan/file.h>
4
5int main()
6{
The metafunction Iterator returns the iterator type for a given container type.
7    seqan::String<char> str = "admn";
8    seqan::Iterator<seqan::String<char> >::Type it = begin(str);
9    seqan::Iterator<seqan::String<char> >::Type itEnd = end(str);
We can use iterators to iterate over the elements of a container.
10    while (it != itEnd) {
11        std::cout << *it;
12        ++it;
13    }
14    std::cout << std::endl;
Rooted iterators know their container (Rooted Iterator). Hence, the functions goBegin and atEnd do not get str as an argument. The following loop increments each character in str.
15    seqan::Iterator<seqan::String<char>, seqan::Rooted >::Type it2 = begin(str);
16    for (goBegin(it2); !atEnd(it2); goNext(it2)) 
17    {
18        ++value(it2);
19    }
Some iterators support an iteration in reverse order. Note that goPrevious is called before the value of it2 is accessed. Remember that the end position of a container is always the position behind the last item in the container.
20    goEnd(it2);
21    while (!atBegin(it2))              
22    {
23        goPrevious(it2);
24        std::cout << getValue(it2);
25    }
26    std::cout << std::endl;
assignValue can be used to change the value of an iterator.
27    assignValue(begin(str), 'X');
28    std::cout << str << std::endl;
29    
30    return 0;
31}
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