Expression
Source
Download

Expression

This is a simple recursive parser for Expressions. It tries to follow the standards of gnu expr, but does not understand regular expressions. I found it usefull to have a lightwight replacement for the gnu.expr.Parser to use with java code.

The code is free software. Its easy use from java code: Just call: public static synchronized boolean de.herberlin.util.Expr.parse(java.lang.String) throws de.herberlin.util.ExprException. The parser returns true if the given expression results to true, else false, and throws exception if it can't be parsed.

A main() - method is implemented so you can use the parser at the command line or within stream, althought you might find better things for that. Example: echo 3*3==9 | java -jar Expr.jar returns true.

This is a little applet that shows how the parser works:

See source.
Download *.zip 13kb (Source included).

Expression is part of herberlin Bremsserver.