What are the differences between the variations of JEXL?

Does anyone know the best place where I can go to see the differences between the variations of JEXL? I've noted the following so far.

Expression

This only allows for a single command to be executed and the result from that is returned. If you try to use mult开发者_运维知识库iple commands it ignores everything after the first semi-colon and just returns the result from the first command.

Script

This allows you to put multiple commands in the expression and you can use variable assignments, loops, calculations, etc. The result from the last command is returned from the script.

Unified

This is ideal for text. To get a calculation you use the EL-like syntax as in ${someVariable}. The expression that goes between the brackets behaves like a script, not an expression. You can use semi-colons to execute multiple commands and the result from the last command is returned from the script.