func parse_list(l *lexer.Lexer) (VValue, bool) {
token := l.Peek()
switch token.Type {
case ")":
l.Next()
return VNil, true
case "EOF":
return nil, false
case ".":
l.Next()
return parse(l)
}
if car, ok := parse(l); ok {
if cdr, ok := parse_list(l); ok {
if _, ok := cdr.(*VPair); !ok {
if l.Next().Type != ")" {
panic("Can't have multiple cdr expressions")
}
}
return &VPair{car, cdr}, true
}
}
return nil, false
}
