vim: Selectively replacing brackets in a file

Question

I have following text file:

A(B C)
D(E F)
A(G 
H 
I)

I want to convert this to:

modifiedA{B C}
D(E F)
modifiedA{G 
H
I}

Usually, I would use s/A(/modifiedA\{/g and s/)/}/g.

Since I don't want to touch the line with D(E F), this won't work.

Thank you for your comments/help.

Update:

1. The answer should not require human intervention and should be scalable. Hence, using c instead of g is not an option.

2. Also note that A() can be spread across multiple lines.

Answer 1

In order to match a multiline pattern we need \_.\{-} which means non-greedy regex search:

:%s/\(A\)(\(\_.\{-}\))/modified\1{\2}

\( ................ start of a regex group
\) ................ end of a regex group
\_.\{-} ........... non-greedy regex
\1 ................ back reference to the regex group 1

Using very magic option see :h \v.

%s/\v(A)\((\w \_.{-})\)/modified\1{\2}