Grouping of multiple criterias as expression

Question

Dear all
I want to do a grouping of multiple criterias as expression .
Single grouping is possible , but when group within a group comes things doesnt work for me.
User would define the comibination
For example i have 4 criterias
C1
C2
C3
C4
Basic grouping works for example :
(C1&C2) | (C3&C4)
Complicated grouping i have no idea how to implement it.
(((C1&C2) | (C3&C4))&(C1&C2) )
I need validate if the expression is correct and need to pick up all the groups and do the AND or OR.
Any help woul dbe appriciated
Regards
pacs

Answer 1

fiveohg wrote:
Complicated grouping i have no idea how to implement it.
(((C1&C2) | (C3&C4))&(C1&C2) )
I need validate if the expression is correct and need to pick up all the groups and do the AND or OR.As already suggested: you could write your own grammar and let a parser-generator create a lexer/parser for you.
Another option is to use some scripting engine and bind your C-variables before evaluating your expression:
import javax.script.*;
public class Foo {
  public static void main(String[] args) throws Exception {
      String expression = "(((C1 && C2) || (C3 && C4)) && (C1 && C2))";
      ScriptEngineManager manager = new ScriptEngineManager();
      ScriptEngine engine = manager.getEngineByName("js");
      engine.put("C1", true);
      engine.put("C2", true);
      engine.put("C3", false);
      engine.put("C4", true);
      System.out.println(engine.eval(expression));
}Note that you cannot user '|' and '&', in that case.
The JavaScript (Rhino) engine is built-in in Java 6, but there are more that can be imported: [https://scripting.dev.java.net/]