enum Type judgeNext()
{
enum Type rType;
switch(syn)
{
case _Eql:
rType=NextExpression();
if(rType==_Type_Void)
error(Eql_Void);
break;
case _Compare:
rType=NextExpression();
if(rType==_Type_Void)
error(Com_Void);
break;
case _Op_Add:
case _Op_Mul:
rType=NextExpression();
if(rType==_Type_Void)
error(Op_Void);
break;
case _Sem:
if(!NeedSem) error(Unexp_Sem);
else getNextSyn();
break;
default:
if(NeedSem) error(Exp_Sem);
break;
}
return rType;
}
/* Recognize and Translate a Relational "Greater Than" */
void Greater()
{
Next();
if (Token == '=') {
NextExpression();
SetGreaterOrEqual();
} else {
CompareExpression();
SetGreater();
}
}
enum Type expression()
{
WordTree* wdt;
FunTree* ft;
char tmp[Max_word_length];
int tNDS,len;
enum Type rType;
switch(syn)
{
case _Id:
if(!getNextSyn_Noend())
return _Type_Void;
switch(syn)
{
case _Br_Sq_Left:// array
wdt=WordFind(now);
if(wdt==NULL)
error(Word_NoFound);
if(wdt&&wdt->type!=_Type_Int_arr)
error(Use_var_to_arr);
if(!getNextSyn_Noend()) return _Type_Void;
tNDS=NeedSem;
NeedSem=0;
rType=expression();
NeedSem=tNDS;
if(rType==_Type_Void)
error(Br_Void);
if(syn!=_Br_Sq_Right)
error(Exp_Br_Sq_Right);
if(!getNextSyn_Noend()) return _Type_Int;
judgeNext();
rType=_Type_Int;
break;
case _Eql: //assignment
wdt=WordFind(now);
if(wdt==NULL)
error(Word_NoFound);
if(wdt&&wdt->type!=_Type_Int)
error(Use_arr_to_var);
rType=NextExpression();
if(rType==_Type_Void)
error(Eql_Void);
break;
case _Compare:
wdt=WordFind(now);
if(wdt==NULL)
error(Word_NoFound);
if(wdt&&wdt->type!=_Type_Int)
error(Use_arr_to_var);
rType=NextExpression();
if(rType==_Type_Void)
error(Com_Void);
break;
case _Op_Add:
case _Op_Mul:
wdt=WordFind(now);
if(wdt==NULL)
error(Word_NoFound);
if(wdt&&wdt->type!=_Type_Int)
error(Use_arr_to_var);
rType=NextExpression();
if(rType==_Type_Void)
error(Op_Void);
break;
case _Br_Sm_Left: //function
ft=FunTree_find(now);
if(ft==NULL)
{
rType=_Type_Void;
error(Fun_NoFound);
while(getNextSyn_Noend())
if(syn==_Br_Sm_Right)
break;
}
else
{
JudgePara(ft->para);
rType=ft->type;
}
// if(getNextSyn_Noend()) return rType;
judgeNext();
break;
case _Sem: //end expression
wdt=WordFind(now);
if(wdt)
rType=wdt->type;
else
{
error(Word_NoFound);
rType=_Type_Void;
}
if(!NeedSem) error(Unexp_Sem);
else getNextSyn();
break;
default:
if(NeedSem)error(Exp_Sem);
wdt=WordFind(now);
if(wdt)
rType=wdt->type;
else
{
error(Word_NoFound);
rType=_Type_Void;
}
break;
}
break;
case _Digit:
if(!getNextSyn_Noend()) return _Type_Int;
rType=_Type_Int;
judgeNext();
break;
case _If:
if(!getNextSyn_Noend()) return _Type_Void;
if(syn!=_Br_Sm_Left)
error(Exp_Br_Sm_Left);
if(!getNextSyn_Noend()) return _Type_Void;
tNDS=NeedSem;
NeedSem=0;
rType=expression();
NeedSem=tNDS;
if(rType==_Type_Void)
error(Br_Void);
if(syn!=_Br_Sm_Right)
error(Exp_Br_Sm_Right);
if(!getNextSyn_Noend()) return _Type_Void;
if(syn==_Br_Big_Left)
{
ReadExprssions();
if(!getNextSyn_Noend()) return _Type_Void;
}
else
{
expression();
// if(!getNextSyn_Noend()) return _Type_Void;
}
if(syn==_Else)
{
if(!getNextSyn_Noend()) return _Type_Void;
if(syn==_Br_Big_Left)
{
ReadExprssions();
if(!getNextSyn_Noend()) return _Type_Void;
}
else
{
expression();
// if(!getNextSyn_Noend()) return _Type_Void;
}
}
rType=_Type_Void;
break;
case _While:
if(!getNextSyn_Noend()) return _Type_Void;
if(syn!=_Br_Sm_Left)
error(Exp_Br_Sm_Left);
if(!getNextSyn_Noend()) return _Type_Void;
tNDS=NeedSem;
NeedSem=0;
rType=expression();
NeedSem=tNDS;
if(rType==_Type_Void)
error(Br_Void);
if(syn!=_Br_Sm_Right)
error(Exp_Br_Sm_Right);
if(!getNextSyn_Noend()) return _Type_Void;
if(syn==_Br_Big_Left)
{
ReadExprssions();
if(!getNextSyn_Noend()) return _Type_Void;
}
else expression();
rType=_Type_Void;
break;
case _Return:
if(!getNextSyn_Noend()) return _Type_Void;
rType=expression();
if(Stack_p==0)
error(Global_Return);
else if(rType!=FunTreeStack[Stack_p]->type)
error(Fun_Return);
rType=_Type_Void;
break;
case _Int: //local defination
if(!getNextSyn_Noend())
return _Type_Void;
if(syn!=_Id)
error(Exp_Id);
if(!getNextSyn_Noend())
return _Type_Void;
switch(syn)
{
case _Sem:
if(WordFind(now))
error(Re_declared);
else
Word_insert(now,_Type_Int);
if(getNextSyn_Noend()) return _Type_Void;
break;
case _Br_Sq_Left:
if(WordFind_now(now))
{
error(Re_declared);
do
{
if(!getNextSyn_Noend())
return _Type_Void;
}
while(syn!=_Br_Sq_Right);
}
else
{
strcpy(tmp,now);
if(!getNextSyn_Noend())
return _Type_Void;
if(syn!=_Digit)
error(Exp_Constant);
else
{
sscanf(now,"%d",&len);
Word_insert(tmp,_Type_Int_arr,len);
if(!getNextSyn_Noend())
return _Type_Void;
if(syn!=_Br_Sq_Right)
error(Exp_Br_Sq_Right);
}
if(!getNextSyn_Noend())
return _Type_Void;
if(syn!=_Sem)
error(Exp_Sem);
else getNextSyn();
}
break;
case _Br_Sm_Left:
error(Fun_InFun);
while(syn!=_Br_Sm_Right)
if(getNextSyn_Noend()) return _Type_Void;
break;
default :
error(Exp_Sem);
break;
}
break;
case _Br_Sm_Left:
if(!getNextSyn_Noend()) return _Type_Void;
tNDS=NeedSem;
NeedSem=0;
rType=expression();
NeedSem=tNDS;
if(rType!=_Type_Int)
error(Br_Void);
if(syn!=_Br_Sm_Right)
error(Exp_Br_Sm_Right);
else if(!getNextSyn_Noend()) return _Type_Void;
judgeNext();
break;
default:
error(Unexp_err);
getNextSyn_Noend();
rType=_Type_Void;
}
return rType;
}
/* Recognize and Translate a Relational "Less or Equal" */
void LessOrEqual()
{
NextExpression();
SetLessOrEqual();
}
/* Recognize and Translate a Relational "Not Equals" */
void NotEqual()
{
NextExpression();
SetNEqual();
}
/* Recognize and Translate a Relational "Equals" */
void Equals()
{
NextExpression();
SetEqual();
}
