Using string variables in condition.

[0xfk0]

Currently if and while operators interpret condition as integral number. And if the condition is empty or is not the integral number, result will be zero (or false). This causes disambiguity: there is no possibility to distinguish between empty string and the string containing zero (or string beginning from "0" and which is not octal number).

Due to this problem, it is impossible to implement very basic list operations such as "foreach", because empty string (or list) cannot be distinguished from non-empty string.