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Topic: Expression evaluator with multiple outputs

Author	Message
snovotill Joined: Feb 8, 2013 Posts: 80	Posted: Oct 27, 2013 10:27 PM    Post subject: Expression evaluator with multiple outputs Hi Jarek/all, here's a good ExpressionEvaluator problem for the forum: I'm able to use nested Ternary operators, as well as multiple outputs, but something goes wrong when I try to use both together. The following expression fails to compile. I've run into this situation several times so I'm reaching out for a fix: In1==-1 ? Out1=0;Out2=0 : In1==0 ? Out1=1;Out2=0 : Out1=1;Out2=1 Thanks kindly, ...Stepan
jarek Joined: Oct 22, 2007 Posts: 1073	Posted: Oct 27, 2013 11:03 PM    Post subject: You can't use the tenary operator across multiple outputs. If you wish to use multiple outputs, then each output starts with OutX= and ends with a semicolon. That is main level.
snovotill Joined: Feb 8, 2013 Posts: 80	Posted: Oct 29, 2013 2:51 AM    Post subject: Okay. I was just about to implement a Programmable Logic Array inside ExpressionEvaluator. And so the simple work around will be to use a separate ExpressionEvaluator for each output. Cheers.
snovotill Joined: Feb 8, 2013 Posts: 80	Posted: Nov 2, 2013 10:03 PM    Post subject: I'm getting a lot of this, so here's one last kick at the cat Jarek/All: Consider this typical ExpressionEvaluator scenario for instance: (In1==0 && In2!=0) ? 1:0 It seems to me that the core expression should evaluate to 0 or 1 directly: Out1=(In1==0 && In2!=0) But the skeleton above fails to compile in expressionEvaluator. I've tried curly brackets, backticks, the \"if\", and various combinations of many different things. Is there a way to force this to evaluate without the need for Ternary, so I can use multiple outputs? thanks kindly
jarek Joined: Oct 22, 2007 Posts: 1073	Posted: Nov 2, 2013 11:54 PM    Post subject: No, the Out1=(In1==0 && In2!=0) will not evaluate directly. Because in java (unlike in C) boolean value (the result of the this expression's right side) is a different type than a number (e.g. float or integer). So it can't be assigned directly, it has to be converted to a number first.
jarek Joined: Oct 22, 2007 Posts: 1073	Posted: Nov 4, 2013 5:52 AM    Post subject: I am not sure if that can make any difference for what you are doing. But it is possible to use output variables as input variables in an expression. For example: Out1=In1;Out2=Out1*2;Out3=Out2>0?Out1:0 The expression is resolved from left to right. So in the above the first is Out1, then Out2 etc.
snovotill Joined: Feb 8, 2013 Posts: 80	Posted: Nov 5, 2013 11:34 PM    Post subject: Very cool! I'm glad you posted that Jarek, thanks.