public static char ESCAPE_MARK = '\\'; //转义符号
public Element Read(ExpressionReader sr)
{
int index = sr.GetCurrentIndex();
var sb = new StringBuilder();
int b = sr.Read();
if (b == -1 || b != START_MARK)
{
throw new FormatException("不是有效的字符窜开始");
}
while ((b = sr.Read()) != -1)
{
char c = (char)b;
if (c == ESCAPE_MARK)
{//遇到转义字符
c = GetEscapeValue((char)sr.Read());
}
else if (c == END_MARK)
{//遇到非转义的引号
return(new Element(sb.ToString(), index, ElementType.STRING));
}
sb.Append(c);
}
throw new FormatException("不是有效的字符窜结束");
}
public Element Read(ExpressionReader sr)
{
int index = sr.GetCurrentIndex();
StringBuilder sb = new StringBuilder();
int b = sr.Read();
if (b == -1 || b != START_MARK)
{
throw new FormatException("不是有效的时间开始");
}
while ((b = sr.Read()) != -1)
{
char c = (char)b;
if (c == END_MARK)
{
return(new Element(FormatTime(sb.ToString()),
index, ElementType.DATE));
}
if (DATE_CHARS.IndexOf(c) == -1)
{
throw new FormatException("时间类型不能包函非法字符：" + c);
}
sb.Append(c);
}
throw new FormatException("不是有效的时间结束");
}
public static string DOUBLE_MARKS = "dD"; //double的结尾标志
public Element Read(ExpressionReader sr)
{
int index = sr.GetCurrentIndex();
string s = string.Empty;
int b = -1;
while ((b = sr.Read()) != -1)
{
char c = (char)b;
if (NUMBER_CHARS.IndexOf(c) == -1)
{
if (LONG_MARKS.IndexOf(c) >= 0)
{
if (s.IndexOf(".") >= 0)
{//有小数点
throw new FormatException("long类型不能有小数点");
}
return(new Element(s.ToString(), index, ElementType.LONG));
}
else if (FLOAT_MARKS.IndexOf(c) >= 0)
{
CheckDecimal(s);
return(new Element(s.ToString(), index, ElementType.FLOAT));
}
else if (DOUBLE_MARKS.IndexOf(c) >= 0)
{
CheckDecimal(s);
return(new Element(s.ToString(), index, ElementType.DOUBLE));
}
else
{
sr.Reset();
if (s.IndexOf(".") >= 0)
{//没有结束标志，有小数点，为double
CheckDecimal(s);
return(new Element(s.ToString(), index, ElementType.DOUBLE));
}
else
{//没有结束标志，无小数点，为int
return(new Element(s.ToString(), index, ElementType.INT));
}
}
}
s += c;
sr.Mark(0);
}
//读到结未
if (s.IndexOf(".") >= 0)
{//没有结束标志，有小数点，为double
CheckDecimal(s);
return(new Element(s.ToString(), index, ElementType.DOUBLE));
}
else
{//没有结束标志，无小数点，为int
return(new Element(s.ToString(), index, ElementType.INT));
}
}
public static string SPLITOR_CHAR = "(),";//所有分割符
public Element Read(ExpressionReader sr)
{
int index = sr.GetCurrentIndex();
int b = sr.Read();
char c = (char)b;
if (b == -1 || SPLITOR_CHAR.IndexOf(c) == -1)
{
throw new FormatException("不是有效的分割字符");
}
return(new Element(c.ToString(), index,
ElementType.SPLITOR));
}
public Element Read(ExpressionReader sr)
{
int index = sr.GetCurrentIndex();
var sb = new StringBuilder();
int b = sr.Read();
if (b == -1)
{
throw new FormatException("表达式已结束");
}
char c = (char)b;
sb.Append(c);
if (IsOperatorWord(sb.ToString()))
{
if (sb.Length == 1)
{//两个符号的运算符优先，如<=，不应该认为是<运算符
sr.Mark(0);
b = sr.Read();
if (b != -1)
{
if (IsOperatorWord(sb.ToString() + (char)b))
{
return(new Element(sb.ToString() + (char)b, index,
ElementType.OPERATOR));
}
}
sr.Reset();
}
return(new Element(sb.ToString(), index,
ElementType.OPERATOR));
}
while ((b = sr.Read()) != -1)
{
c = (char)b;
sb.Append(c);
if (IsOperatorWord(sb.ToString()))
{
return(new Element(sb.ToString(), index,
ElementType.OPERATOR));
}
if (VariableTypeReader.STOP_CHAR.IndexOf(c) >= 0)
{//单词停止符
throw new FormatException("不是有效的运算符：" + sb.ToString());
}
}
throw new FormatException("不是有效的运算符结束");
}
public Element Read(ExpressionReader sr)
{
int index = sr.GetCurrentIndex();
string word = ReadWord(sr);
if (TRUE_WORD.Equals(word) || FALSE_WORD.Equals(word))
{
return(new Element(word, index, ElementType.BOOLEAN));
}
else if (NULL_WORD.Equals(word))
{
return(new Element(word, index, ElementType.NULL));
}
else
{
return(new Element(word, index, ElementType.VARIABLE));
}
}
public static char END_MARK = '('; //函数结束
/**
* 从流中读取函数类型的ExpressionToken
* @param sr
* @return
* @throws FormatException
* @throws IOException
*/
public Element Read(ExpressionReader sr)
{
int index = sr.GetCurrentIndex();
var sb = new StringBuilder();
int b = sr.Read();
if (b == -1 || b != START_MARK)
{
throw new FormatException("不是有效的函数开始");
}
bool readStart = true;
while ((b = sr.Read()) != -1)
{
char c = (char)b;
if (c == END_MARK)
{
if (sb.Length == 0)
{
throw new FormatException("函数名称不能为空");
}
sr.Reset();
return(new Element(sb.ToString(), index, ElementType.FUNCTION));
}
//if (!Character.isJavaIdentifierPart(c)) {
// throw new FormatException("名称不能为非法字符：" + c);
//}
if (readStart)
{
//if (!Character.isJavaIdentifierStart(c)) {
// throw new FormatException("名称开头不能为字符：" + c);
//}
readStart = false;
}
sb.Append(c);
sr.Mark(0);
}
throw new FormatException("不是有效的函数结束");
}
