Evaluate string expression in c#

mesharaasi

4y1.1kVisual Basic .NET

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.

6 Replies

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Muhammad Imran Ansari4y ago
Accepted 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 < values.Length; 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)
+3
Asad Ali4y ago
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.
+1
mesharaasi4y ago
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)
+1
Asad Ali4y ago
Can you write the set of rules so it would be easy for conversion.
+1
Muhammad Imran Ansari4y ago
Sure. Just confirm one thing, while conversion somewhere you're using NOT and somewhere EQ in start. What's the logic behind this?
+1
mesharaasi4y ago
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.
+1