public static OperatorPriority GetPriority(PhraseTypeEnum pt)
{
if (pt == PhraseTypeEnum.ln || pt == PhraseTypeEnum.log || pt == PhraseTypeEnum.lg)
{
return(OperatorPriority.P5);
}
else if (pt == PhraseTypeEnum.sin || pt == PhraseTypeEnum.end || pt == PhraseTypeEnum.tg ||
pt == PhraseTypeEnum.abs || pt == PhraseTypeEnum.when || pt == PhraseTypeEnum.case_ ||
pt == PhraseTypeEnum.atg || pt == PhraseTypeEnum.then)
{
return(OperatorPriority.P4);
}
else if (pt == PhraseTypeEnum.greater)
{
return(OperatorPriority.P6);
}
else if (pt == PhraseTypeEnum.less)
{
return(OperatorPriority.P6);
}
else if (pt == PhraseTypeEnum.equal)
{
return(OperatorPriority.P6);
}
else if (pt == PhraseTypeEnum.plus)
{
return(OperatorPriority.P1);
}
else if (pt == PhraseTypeEnum.minus)
{
return(OperatorPriority.P1);
}
else if (pt == PhraseTypeEnum.mutiple)
{
return(OperatorPriority.P2);
}
else if (pt == PhraseTypeEnum.mod || pt == PhraseTypeEnum.divide)
{
return(OperatorPriority.P2);
}
else if (pt == PhraseTypeEnum.leftbracket)
{
return(OperatorPriority.P0);
}
else if (pt == PhraseTypeEnum.sharp)
{
return(OperatorPriority.P0);
}
else
{
return(OperatorPriority.Unknown);
}
}
/// <summary>
/// 根据运算符返回对应的运算目数
/// </summary>
/// <param name="Phrase">运算符</param>
/// <returns>运算目数</returns>
public static OperandType OperandCount(PhraseTypeEnum pt)
{
//分析运算符的目数
if (pt == PhraseTypeEnum.end || pt == PhraseTypeEnum.sin || pt == PhraseTypeEnum.when ||
pt == PhraseTypeEnum.case_ || pt == PhraseTypeEnum.case_ || pt == PhraseTypeEnum.then ||
pt == PhraseTypeEnum.atg || pt == PhraseTypeEnum.cbrt || pt == PhraseTypeEnum.else_ ||
pt == PhraseTypeEnum.lg || pt == PhraseTypeEnum.ln || pt == PhraseTypeEnum.tg || pt == PhraseTypeEnum.abs || pt == PhraseTypeEnum.equal || pt == PhraseTypeEnum.greater || pt == PhraseTypeEnum.less)
{
return(OperandType.O1);
}
else if (pt == PhraseTypeEnum.divide || pt == PhraseTypeEnum.plus || pt == PhraseTypeEnum.minus ||
pt == PhraseTypeEnum.mutiple || pt == PhraseTypeEnum.mod || pt == PhraseTypeEnum.log)
{
return(OperandType.O2);
}
else
{
return(OperandType.O0);
}
}
/// <summary>
/// 词法分析
/// </summary>
/// <returns>是否成功</returns>
private bool Analyze()
{
int i = 0;
int startpos = 0, endpos = 0;
//设置初态
_prestate = DFAState.S0;
while (i < _chArray.Length)
{
//未知态处理，出错返回
if (_prestate == DFAState.SX)
{
_succeed = false;
return(false);
}
if (Char.IsLetter(_chArray[i]))
{
//字母
if (_prestate == DFAState.S0)
{
//初态变字母串
_prestate = DFAState.S3;
}
else if (_prestate == DFAState.S1)
{
endpos = i - 1; //保存结束位置
////检查字母串的匹配类型
//if (CheckString(startpos, endpos) == true)
//{
// SavePhrase(startpos, endpos);
// startpos = i;
//}
_prestate = DFAState.S3;
}
else if (_prestate == DFAState.S2)
{
endpos = i - 1; //保存结束位置
//检查字母串的匹配类型
if (CheckString(startpos, endpos) == true)
{
SavePhrase(startpos, endpos);
startpos = i;
}
_prestate = DFAState.S3;
}
else if (_prestate == DFAState.S17)
{
endpos = i - 1; //保存结束位置
//检查字母串的匹配类型
if (CheckString(startpos, endpos) == true)
{
SavePhrase(startpos, endpos);
startpos = i;
}
_prestate = DFAState.S3;
}
else if (_prestate != DFAState.S3)
{
//处理前一个词
endpos = i - 1; //保存结束位置
SavePhrase(startpos, endpos);
//非字母串转换为字母串
_prestate = DFAState.S3;
//保存开始位置
startpos = i;
}
else //之前的状态为字母串DFAState.S3
{
endpos = i - 1; //保存结束位置
//检查字母串的匹配类型
if (CheckString(startpos, endpos) == true)
{
SavePhrase(startpos, endpos);
startpos = i;
}
}
}
else if (Char.IsDigit(_chArray[i]))
{
//数字
if (_prestate == DFAState.S0)
{
//初态
_prestate = DFAState.S1;
startpos = i; //保存开始位置
}
else if (_prestate == DFAState.S1)
{
//整数串，状态不变
}
else if (_prestate == DFAState.S2) //浮点数串
{
_prestate = DFAState.S2;
}
else if (_prestate == DFAState.S3) //字母
{
_prestate = DFAState.S2;
}
else if (_prestate == DFAState.S17) //_
{
_prestate = DFAState.S2;
}
else
{
//处理前一个词
endpos = i - 1; //保存结束位置
//字符串类型检查
if (_prestate == DFAState.S3 && CheckString(startpos, endpos) == false)
{
return(false); //如果前一个状态为字符串态，且字符串匹配失败，则退出
}
else
{
SavePhrase(startpos, endpos);
}
//从非数字串转换为整数串
_prestate = DFAState.S1;
//保存开始位置
startpos = i;
}
}
else if (_chArray[i] == '.')
{
//小数点
if (_prestate == DFAState.S1 || _prestate == DFAState.S0)
{
_prestate = DFAState.S2; //由整数串或初态变为浮点数串
}
else
{ //未知态
// 需要讨论: 是否保存前一个词
//_prestate = DFAState.SX;
}
}
else if (_chArray[i] == '_')
{
_prestate = DFAState.S17;
}
else if (Char.IsWhiteSpace(_chArray[i]))
{
//空格，跳过
//处理前一个词
endpos = i - 1;
//字符串类型检查
//if (_prestate == DFAState.S3 && CheckString(startpos, endpos) == false)
// return false; //如果前一个状态为字符串态，且字符串匹配失败，则退出
//else
SavePhrase(startpos, endpos);
startpos = i + 1;
_prestate = DFAState.S0;
}
//else if (_chArray[i] == '+' || _chArray[i] == '-' || _chArray[i] == '*' || _chArray[i] == '/' || _chArray[i] == '^' || _chArray[i] == '%' || _chArray[i] == '(' || _chArray[i] == ')' || _chArray[i] == '!' || _chArray[i] == '#' || _chArray[i] == '@' || _chArray[i] == '=')
else if (_chArray[i] == '+' || _chArray[i] == '-' || _chArray[i] == '*' || _chArray[i] == '/' || _chArray[i] == '(' || _chArray[i] == ')' || _chArray[i] == '#' || _chArray[i] == '=' || _chArray[i] == '>' || _chArray[i] == '<')
{
if (_prestate != DFAState.S0)
{
//处理前一个词
endpos = i - 1;
//字符串类型检查
//if (_prestate == DFAState.S3 && CheckString(startpos, endpos) == false)
// return false; //如果前一个状态为字符串态，且字符串匹配失败，则退出
//else
SavePhrase(startpos, endpos);
}
if (_chArray[i] == '-')
{
if (_ps.PhraseTypeResult.Length > 0)
{
PhraseTypeEnum prept = _ps.PhraseTypeResult[_ps.PhraseTypeResult.Length - 1];
if (prept != PhraseTypeEnum.ax && prept != PhraseTypeEnum.bx && prept != PhraseTypeEnum.cx && prept != PhraseTypeEnum.dx && prept != PhraseTypeEnum.ex && prept != PhraseTypeEnum.fx && prept != PhraseTypeEnum.clr && prept != PhraseTypeEnum.sto && prept != PhraseTypeEnum.rightbracket && prept != PhraseTypeEnum.number)
{
_chArray[i] = '@';
}
}
else
{
_chArray[i] = '@';
}
}
if (_chArray[i] == '+')
{
_prestate = DFAState.S4;
}
else if (_chArray[i] == '-')
{
_prestate = DFAState.S5;
}
else if (_chArray[i] == '*')
{
_prestate = DFAState.S6;
}
else if (_chArray[i] == '/')
{
_prestate = DFAState.S7;
}
else if (_chArray[i] == '=') //not support so far
{
_prestate = DFAState.S11;
}
else if (_chArray[i] == '>') //not support so far
{
_prestate = DFAState.S11;
}
else if (_chArray[i] == '<') //not support so far
{
_prestate = DFAState.S11;
}
else if (_chArray[i] == '%')
{
_prestate = DFAState.S8;
}
else if (_chArray[i] == '^')
{
_prestate = DFAState.S10;
}
else if (_chArray[i] == '(')
{
_prestate = DFAState.S12;
}
else if (_chArray[i] == ')')
{
_prestate = DFAState.S13;
}
else if (_chArray[i] == '!')
{
_prestate = DFAState.S9;
}
else if (_chArray[i] == '#')
{
_prestate = DFAState.S14;
}
else if (_chArray[i] == '@')
{
_prestate = DFAState.S15;
}
//保存开始位置
startpos = i;
}
else
{
//未知字符，进入未知态
//_prestate=DFAState.SX;
_prestate = DFAState.S3;
}
i++;
}
return(true);
}
/// <summary>
/// 添加一个词和它对应的词类
/// </summary>
/// <param name="phrase">词</param>
/// <param name="pt">词类</param>
public void AddPhraseResult(string phrase, PhraseTypeEnum pt)
{
_scOutput.Add(phrase);
_stcOutput.Add(pt);
}
/// <summary>
/// 添加一个词类
/// </summary>
/// <param name="pt">词类</param>
public void AddPhraseType(PhraseTypeEnum pt)
{
_stcOutput.Add(pt);
}
/// <summary>
/// 虚拟运算（不进行真实的计算）
/// </summary>
/// <returns>是否有错误发生</returns>
private bool FakeCalculate()
{
PhraseTypeEnum pt = (PhraseTypeEnum)_optr.Pop();
OperandType oc = Operator.OperandCount(pt); //栈顶运算符目数
PhraseTypeEnum temp_pt; //存储_op中pop出的一个符号
switch (oc)
{
case OperandType.O0: //0目运算符，不存在
_lastOpForError = pt;
return(false);
//_op.Pop();
//break;
case OperandType.O1: //1目运算符
if (_opnd.Count >= 1)
{
_opnd.Pop();
_op.Pop(); //抛出数符
}
else
{ //没有足够的数符用于匹配运算符，出错
_lastOpForError = pt;
return(false);
}
temp_pt = (PhraseTypeEnum)_op.Pop();
//抛出运算符，邻近符号检查
if (Operator.OperatorCmp((PhraseTypeEnum)_op.Peek(), temp_pt) == PriorityCmpType.Unknown)
{
_lastOpForError = pt;
return(false);
}
_opnd.Push(PhraseTypeEnum.number);
_op.Push(PhraseTypeEnum.number);
break;
case OperandType.O2: //2目运算符
if (_opnd.Count >= 2)
{
_opnd.Pop();
_opnd.Pop();
_op.Pop(); //抛出数符
}
else
{
_lastOpForError = pt;
return(false);
}
temp_pt = (PhraseTypeEnum)_op.Pop();
//抛出数符，邻近符号检查
if (Operator.OperatorCmp((PhraseTypeEnum)_op.Peek(), temp_pt) == PriorityCmpType.Unknown)
{
_lastOpForError = pt;
return(false);
}
temp_pt = (PhraseTypeEnum)_op.Pop();
//抛出运算符，邻近符号检查
if (Operator.OperatorCmp((PhraseTypeEnum)_op.Peek(), temp_pt) == PriorityCmpType.Unknown)
{
_lastOpForError = pt;
return(false);
}
_opnd.Push(PhraseTypeEnum.number);
_op.Push(PhraseTypeEnum.number);
break;
}
return(true);
}
/// <summary>
/// 检查文法
/// </summary>
/// <returns>是否正确</returns>
public bool Check()
{
msg = string.Empty;
_optr.Clear();
_optr.Push(PhraseTypeEnum.sharp); //将#作为栈操作结束标志
_opnd.Clear();
_op.Clear();
_op.Push(PhraseTypeEnum.sharp); //将#作为栈操作结束标志
int i = 0;
while (i < _ps.Length)
{
PhraseTypeEnum temp_pt = _ps.PhraseTypeResult[i];
if (temp_pt == PhraseTypeEnum.case_)
{
int n1 = -1, n2 = -1, n3 = -1, n4 = -1;
int k1 = -1, k2 = -1, k3 = -1, k4 = -1;
n1 = i + 1;
while (n1 < _ps.Length)
{
if (_ps.PhraseTypeResult[n1] == PhraseTypeEnum.when)
{
k1 = n1;
break;
}
n1++;
}
n2 = n1 + 1;
while (n2 < _ps.Length)
{
if (_ps.PhraseTypeResult[n2] == PhraseTypeEnum.then)
{
k2 = n2;
break;
}
n2++;
}
n3 = n2 + 1;
while (n3 < _ps.Length)
{
if (_ps.PhraseTypeResult[n3] == PhraseTypeEnum.else_)
{
k3 = n3;
break;
}
n3++;
}
n4 = n3 + 1;
while (n4 < _ps.Length)
{
if (_ps.PhraseTypeResult[n4] == PhraseTypeEnum.end)
{
k4 = n4;
break;
}
n4++;
}
if (k4 == -1)
{
msg = "case when then else end 语句不完整";
return(false);
}
if ((k4 - k3) == 1)
{
msg = "case when then else end 语句有误，else和end之间不能为空";
return(false);
}
if ((k3 - k2) == 1)
{
msg = "case when then else end 语句有误，then和else之间不能为空";
return(false);
}
if ((k2 - k1) == 1)
{
msg = "case when then else end 语句有误，when和then之间不能为空";
return(false);
}
i = k4;
temp_pt = PhraseTypeEnum.number;
}
//运算前算符相邻检查
PriorityCmpType temp_pct = (PriorityCmpType)Operator.OperatorCmp((PhraseTypeEnum)_op.Peek(), temp_pt);
if (temp_pct == PriorityCmpType.Unknown)
{
_lastOpForError = temp_pt;
return(false);
}
//假运算处理
if (temp_pt == PhraseTypeEnum.number || temp_pt == PhraseTypeEnum.e || temp_pt == PhraseTypeEnum.pi || temp_pt == PhraseTypeEnum.ans ||
temp_pt == PhraseTypeEnum.ax || temp_pt == PhraseTypeEnum.bx || temp_pt == PhraseTypeEnum.cx || temp_pt == PhraseTypeEnum.dx ||
temp_pt == PhraseTypeEnum.ex || temp_pt == PhraseTypeEnum.fx)
{ //是数
_opnd.Push(PhraseTypeEnum.number);
_op.Push(PhraseTypeEnum.number);
}
else //是运算符
{
//运算结束
if ((PhraseTypeEnum)_optr.Peek() == PhraseTypeEnum.sharp && temp_pt == PhraseTypeEnum.sharp)
{
break;
}
temp_pct = (PriorityCmpType)Operator.OperatorCmp2((PhraseTypeEnum)_optr.Peek(), temp_pt);
if (temp_pct == PriorityCmpType.Higher)
{
do
{
if (this.FakeCalculate() == false) //虚拟运算
{
return(false);
}
} while ((PriorityCmpType)Operator.OperatorCmp2((PhraseTypeEnum)_optr.Peek(), temp_pt) == PriorityCmpType.Higher);
//当相邻PhraseTypeEnum优先级相等时
if ((PriorityCmpType)Operator.OperatorCmp2((PhraseTypeEnum)_optr.Peek(), temp_pt) == PriorityCmpType.Equal)
{
_optr.Pop(); //抛出相等的prePhraseTypeEnum
//对类似于(number)的情况做处理
PhraseTypeEnum pt1 = (PhraseTypeEnum)_op.Pop();
_op.Pop();
_op.Push(pt1);
}
else
{
_optr.Push(temp_pt);
_op.Push(temp_pt);
}
}
else if (temp_pct == PriorityCmpType.Lower)
{
_optr.Push(temp_pt);
_op.Push(temp_pt);
}
else if (temp_pct == PriorityCmpType.Equal)
{
_optr.Pop();
PhraseTypeEnum pt1 = (PhraseTypeEnum)_op.Pop();
_op.Pop();
_op.Push(pt1);
}
else
{ //出现了不允许相邻的符号
_lastOpForError = (PhraseTypeEnum)_optr.Peek();
return(false);
}
}
i++;
}
//数栈检查，如果并非只剩一个元素报错
if (_opnd.Count != 1)
{
_lastOpForError = PhraseTypeEnum.unknown;
return(false);
}
return(true);
}
/// <summary>
/// 有间隔相邻符号比较（只包含数符）
/// </summary>
/// <param name="prePt">前一个符号</param>
/// <param name="postPt">后一个符号</param>
/// <returns>优先级比较值</returns>
public static PriorityCmpType OperatorCmp2(PhraseTypeEnum prePt, PhraseTypeEnum postPt)
{
int result = _priorityTable2[(int)prePt, (int)postPt];
return((PriorityCmpType)result);
}