Cannot loop some expressions in `for` that Jinja2 can

[jpcima]

Hi, I have tried a set of expressions which are not currently working as expected.

1. {% for v in [1, 2] %}{{v}}{% endfor %}
2. {% for v in [1, 2]+[3, 4] %}{{v}}{% endfor %}
3. {% for v in "ab" %}{{v}}{% endfor %}
4. {% for v in "ab"+"cd" %}{{v}}{% endfor %}
5. {% for v in 'a' ~ 'b' %}{{v}}{% endfor %}

According to Jinja2:

1. 12
2. 1234
3. ab
4. abcd
5. ab

In Jinja2cpp, I find only the first one is working, the other 4 evaluate as empty.

I believe that 3 4 and 5 are because it's not handled to loop over characters.
Regarding 2, I'm under impression it's the + operation not supported for concatenating lists. (possibly in scope of issue #135)

[flexferrum]

Hi! Thank you for pointing that out. Actually, you're right. 2 is because of + operator doesn't concatenate lists (but it should? ok). 3, 4, and 5 need checking. Strings should be treated as iterable (in general). But seems like something went wrong. Will check it soon with #178 issue.

[jpcima]

2 is because of + operator doesn't concatenate lists (but it should? ok).

Yes. Lists also recognize a commutative * operator on (List, Int) which repeats N times the sequence.

Strings should be treated as iterable (in general). But seems like something went wrong.

I'm sure the commented part of ListConverter must be relevant to the problem.

Jinja2Cpp/src/internal_value.cpp

Lines 166 to 170 in 78e0a7c

	// template<typename CharT>
	// result_t operator() (const std::basic_string<CharT>& str) const
	// {
	// return result_t(ListAdapter([adaptor = StringAdapter<CharT>(&str)]() {return &adaptor;}));
	// }

[jpcima]

I confirm this worked great, thanks for the work.