Dmitri Blinov created JEXL-168:
----------------------------------
Summary: Dedicated operator for String concatenation
Key: JEXL-168
URL: https://issues.apache.org/jira/browse/JEXL-168
Project: Commons JEXL
Issue Type: Improvement
Reporter: Dmitri Blinov
Priority: Minor
Fix For: 3.0
While overloaded "+" operator basically works with Strings in many cases, it
works with them in unpredictable manner, for example, if we try to concatenate
two parts of IP address with expression "127.0" + "0.1" it will give us the
result 127.1 by successfully trying first to convert both operands to numbers
and perform addtion. In generic algorithm that combines two parts of some code
from database it is hard to say what characters those codes might be consist
of, and when this algorithm will eventually break. I understand that this
syntax has neverthelless a long history, and changing its behaviour may break
many legacy applications. And via the extension of JexlArithmetic we can
override *add* method to support different priority for Strings, but that just
means that default implementation of the very basic operation is not ideal. In
my case I consider refraining from usage of "+" for Strings altogether and
overriding some other operator like "|", with less side effects, but anyway
constructs like 127 | 1 will divert to original implementation. So I suggest
that we could have a dedicated operator for concatenation, like for example in
"EL 3.0" they reserved "+=" for this purpose, and regardless of types of
operands it will convert to strings both parts and return concatenation.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
