View Compilation Error

0_0_24474375_28479.cpp: In function 'vi next()':
0_0_24474375_28479.cpp:44:11: error: a function-definition is not allowed here before '{' token
 vi expr() {
           ^
0_0_24474375_28479.cpp:88:1: error: expected '}' at end of input
 }
 ^