Extracts characters from the string strSource, starting with the first character that are in the set of characters identified by strExclude. If the first character of the string is not in the character set, then SpanIncluding returns an empty string. Otherwise, it returns a sequence of consecutive characters which are in the set. Case sensitive.
string SpanIncluding(string strSource$, string strInclude$ )$
A substring that contains characters in the string strSource that are in strInclude, beginning with the first character in the string and ending when a character is found in the string that is not in strInclude. SpanIncluding returns an empty substring if the first character in the string is not in the specified set.
str2$ = "acB";
SpanIncluding(str1$, str2$)$= ; //should return ca
//Notes: it is best to pass a string variable into this method,
//because in Labtalk method, string will always pass as Uppercase,
//but this method is case sensitive.