Returns a valid Java identifier from the given symbol:
Returns a valid Java identifier from the given symbol:
- appends a '_' in case the symbol is a java keyword or special literal ("null", "true", "false"); - otherwise, prepends a '_' in case the symbol is numerical literal; - otherwise, returns the given symbol if already a valid java identifier; - otherwise, prefixes the symbol with '_' if first character is valid but not at first position, and replaces any character that cannot be part of a java identifier with '_'.
Set of java keywords plus the literals "null", "true", "false".
Set of java keywords plus the literals "null", "true", "false". (from Sect 3.9 of the Java Language Spec, Java SE 8 Edition)