Evaluate string expression in c#

Question

I have string expression as below

NOT (S:sira1_1810 OR S:sira2_1810 OR S:sira3_1810)

It should be converted as

(NOT S:sira1_1810) OR (NOT S:sira2_1810) OR (NOT S:sira3_1810)

Any ideas much appreciated.

Muhammad Imran Ansari · Answer

You can use the following simple code to get your output: string strVal = "NOT (S:sira1_1810 OR S:sira2_1810 OR S:sira3_1810)" ; // Extract text that lies between parentheses (round brackets) strVal = strVal.Split( '(' , ')' )[1]; var values = strVal.Split( new string [] { "OR" }, StringSplitOptions.None); string finalVal = "" ; for ( int i = 0; i { finalVal += "(NOT " + values[i].Trim() + ")" ; if (i != values.Length - 1) finalVal += " OR " ; } Console.WriteLine( "Output: " + finalVal); Output: (NOT S:sira1_1810) OR (NOT S:sira2_1810) OR (NOT S:sira3_1810)

Asad Ali · Answer

so the rules are 1. When there is a no NOT use EQ 2. use AND where there is AND 3. use OR where there is a OR 4. we should have () after each operator which should cover the expression.

mesharaasi · Answer

Thank you. It's a rule engine we are trying to build. Before that we would need to evaluate the expression in correct format. " S:sira1_1810 " are selected options, If the user doesn't select (NOT) means, we need to trigger a message. If there is no "NOT" beside the option means it is "EQ" (equal). Since we need to execute in "AND","OR" order, we have to evaluate expression in the right format EX: #1 Expression: NOT S:24zoll_1757 AND C:1757 AND C:1780 Conversion: (NOT S:24zoll_1757) AND (EQ C:1757) AND (EQ C:1780) #2 Expression: (S:gr1_1778 OR S:gr2_1778 OR S:gr5_1778) Conversion: ((EQ S:gr1_1778) OR (EQ S:gr2_1778) OR (EQ S:gr5_1778)) #3: Expression: S:25zoll_1757 AND S:ber7_1756 Conversion: (EQ S:25zoll_1757) AND (EQ S:ber7_1756) #4: Expression: S:25zoll_1757 AND NOT S:ber7_1756 Conversion: (EQ S:25zoll_1757) AND (NOT S:ber7_1756)

Asad Ali · Answer

Can you write the set of rules so it would be easy for conversion.

Muhammad Imran Ansari · Answer

Sure. Just confirm one thing, while conversion somewhere you're using NOT and somewhere EQ in start. What's the logic behind this?

mesharaasi · Answer

Thank you so much for the solution. Please can you help me with a generic solution in the same pattern? There are other scenarios as well such as: #1 Expression: NOT S:24zoll_1757 AND C:1757 AND C:1780 Conversion: (NOT S:24zoll_1757) AND (EQ C:1757) AND (EQ C:1780) #2 Expression: (S:gr1_1778 OR S:gr2_1778 OR S:gr5_1778) Conversion: ((EQ S:gr1_1778) OR (EQ S:gr2_1778) OR (EQ S:gr5_1778)) #3: Expression: S:25zoll_1757 AND S:ber7_1756 Conversion: (EQ S:25zoll_1757) AND (EQ S:ber7_1756) Thank you.