View Compilation Error

0_0_24474462_31850.cpp: In function 'vi next()':
0_0_24474462_31850.cpp:45:11: error: a function-definition is not allowed here before '{' token
 vi expr() {
           ^
0_0_24474462_31850.cpp:89:1: error: expected '}' at end of input
 }
 ^