Regular Expression的中譯 - Linux

http://mitpress.mit.edu/books/FLAOH/cbnhtml/glossary-R.html
Regular Expression A definition for a class of strings that can be
recognized by a finite-state automaton. An example of a class of strings that
is regular would be legal mathematical expressions using only ``+'' and
digits. An example that is not regular is the same legal mathematical
expressions as before, but with properly nested parentheses.

Ex1:
1+2+3
1+2
+1+2
...

Python RegExp:
import re
print re.match("\+?\d?[\+\d]*", "1+2+3").group(0)


Ex2:
(1+2)
((1)+2)
(((1))+2)
(1+(2))
(1+((2)+(3)))
...

請高手找出剛好match它們的RegExp！？

所以簡單的說regular不是指什麼正不正統，
而是指你能不能找到一個pattern match一組字串。
沒有"規律"的字串組，是找不到對應的pattern！

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