bool Database::isTruth(Staff *st,Exp *filter){
try{
if (filter -> kind != EXP_OP)return true;
//根据C++特性，能够自动短路的
if (filter -> name == "and")
return isTruth(st,filter->lv) && isTruth(st,filter->rv);
if (filter -> name == "or")
return isTruth(st,filter->lv) || isTruth(st,filter->rv);
//剩下的是=,>,<,<>,!=,<=,>=
Exp *lv = filter -> lv;
Exp *rv = filter -> rv;
if (rv->kind == EXP_STR){
//名字，字符串比较
string name = st -> GetName();
if (filter->name[0] == '='){
//防止出现==输入
return MatchStr(name,rv->name);
}else if (filter->name == "!=" || filter -> name == "<>"){
return !MatchStr(name,rv->name);
}
if (filter->name == "<")return name < rv->name;
if (filter->name == ">")return name > rv->name;
if (filter->name == "<=")return name <= rv->name;
if (filter->name == ">=")return name >= rv->name;
}else{
int num = GetStaffValue(st,lv->name);
int vn = STOI(rv->name);
if (filter -> name[0] == '=')return num == vn;
if (filter -> name == "!=" || filter -> name == "<>")return num != vn;
if (filter -> name == "<")return num < vn;
if (filter -> name == ">")return num > vn;
if (filter -> name == "<=")return num <= vn;
if (filter -> name == ">=")return num >= vn;
}
}catch(...){
return false;
}
return true;//出现异常，暂时不处理
}
char* CRegex::ReplaceString(const char* subject, int32 len, const char* repl)
{
if (!subject || fInitCheck != B_OK || fMatchInfos.empty())
return NULL;
BString replStr;
char c;
int rl = strlen(repl);
for(int i=0; i<rl; ++i)
{
c = repl[i];
if (c == '\\' || c == '$')
{
c = repl[++i];
if (c >= '1' && c <= '9')
replStr << MatchStr(subject, c-'0');
else if (c == '\\')
{ // de-escape newline, carriage-return, tab and backslash:
if (c == 'n')
replStr << '\n';
else if (c == 'r')
replStr << '\r';
else if (c == 't')
replStr << '\t';
else if (c == '\\')
replStr << '\\';
}
}
else
replStr << c;
}
char* resBuf = (char*)malloc(replStr.Length()+1);
if (resBuf)
{
replStr.CopyInto(resBuf, 0, replStr.Length());
resBuf[replStr.Length()] = '\0';
}
return resBuf;
}