Dear monks,

I have tried a simple regular expression like,

^[a-zA-Z]+(['.]?\s*[a-zA-Z]+)*$

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to match the following text lines, 
St.John's high school.
A. B. C. school.
Institute of management.
oxford university.
A.B.C college.
Ragu ram's college of technology.

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And at the same time, it chould not match the following lines 
A..B.C college.
St.John''s high school.
St.John'.'s high school.

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The given regular expression is working fine.

But, my question is, is there any other better regex which will work instead of the given one?
And if any other better way, kindly tell me how this is worse than that.
Will a poor regex make a big difference in performance of a program?
How can we validate a efficiency of a regular expressions?

Ofcourse, I have searched in google to some extent.

In reply to About regular expressions by nagalenoj

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