嵌套括号的正则表达式或字符串解析

Question

Consider the following string as input. The second & third AND are redundant. I want to removed it.

Input

 AND(AND(string("test message")),filter(AND(OR(source:string("XYZ"),source:string("ABC")))))

I want the output as

 AND(string("test message"),filter(OR(source:string("XYZ"),source:string("ABC"))))

Basically the input string has AND operator used, but there is only one argument specified, this makes the input a invalid string. I want to modify the string to remove AND such that it has only one argument specified in it.

What should be the best approach. Regular expression or string parsing. My string can be very long.

I checked multiple posts & seems like regular expression is not recommended especially if it is too much nested.

Please suggest the best way to handle this case.

Some input & their output

1. AND(string(""test message""))

string(""test message"")

1. AND(AND(string(""test message"")),filter(AND(OR(source:string(""XYZ""),source:string(""ABC"")))))

   AND(string(""test message""),filter(OR(source:string(""XYZ""),source:string(""ABC""))))

2. AND(string(""test message""),filter(OR(source:string(""XYZ""),source:string(""ABC"")))) AND(string(""test message""),filter(OR(source:string(""XYZ""),source:string(""ABC""))))

Annu

Answer 1

If you go the regex route then a positive lookahead followed by a negative lookahead could work:

string result = Regex.Replace(searchText, "(?i)(?x)(?(?<!AND\\()AND\\()|(?(?=\\){2})(?!\\){3})\\))", "");

Input:

AND(AND(string("test message")),filter(AND(OR(source:string("XYZ"),source:string("ABC")))))

AND(string(""test message""))

AND(string(""test message""),filter(OR(source:string(""XYZ""),source:string(""ABC"")))) 

Result:

AND(string("test message"),filter(OR(source:string("XYZ"),source:string("ABC"))))

string(""test message"")

string(""test message""),filter(OR(source:string(""XYZ""),source:string(""ABC""))) 

Answer 2

I tried it in tcl , this is the soultion

regsub -all {\(AND} $string "" string .u will get the expected output