public static Expression Resolve(string expression)
{
if (string.IsNullOrWhiteSpace(expression))
{
return(null);
}
var lexer = new ExpressionLexer(expression);
var resolve = new ExpressionResolve(lexer.GetToken());
return(resolve.ResolveMatchBegin());
}
/// <summary>
/// 解析表达式块
/// </summary>
/// <param name="e"></param>
/// <returns></returns>
private bool Resolve_Block(out Expression e)
{
if (Current.Value == "(")
{
var nCount = 0;
List <ExpressionToken> tokens = new List <ExpressionToken>();
while (true)
{
if (Current == null)
{
throw new Exception("表达式解析失败,( )不匹配");
}
if (Current.Value == "(")
{
nCount++;
}
else if (Current.Value == ")")
{
nCount--;
}
tokens.Add(Current);
Read();
if (nCount == 0)
{
if (tokens.Count < 2)
{
throw new Exception("表达式解析失败,( )不匹配");
}
tokens.RemoveAt(0);
tokens.RemoveAt(tokens.Count - 1);
if (tokens.Count == 0)
{
throw new Exception("表达式解析失败, 无效的( ), 没有任何意义");
}
e = new ExpressionResolve(tokens.ToArray()).Resolve();
return(true);
}
}
}
e = null;
return(false);
}
/// <summary>
/// 解析方法
/// </summary>
/// <param name="e"></param>
/// <returns></returns>
private bool Resolve_Function(out Expression e)
{
e = null;
if (Current.Type != ExpressionToken.eType.Identifier)
{
return(false);
}
if (Peek.Value != "(")
{
return(false);
}
var rFunction = new ExpressionFunction(Current.Value);
// 所有参数列表
var rListToken = new List <ExpressionToken>();
var rListParameter = new List <ExpressionToken>();
Read();
var nCount = 0;
while (true)
{
if (Current.Value == "(")
{
nCount++;
}
else if (Current.Value == ")")
{
nCount--;
if (0 == nCount)
{
Read();
break;
}
}
rListToken.Add(Current);
Read();
}
// 移除开始与结束的括号
rListToken.RemoveAt(0);
rListToken.Add(new ExpressionToken(ExpressionToken.eType.End, null));
foreach (var rToken in rListToken)
{
if (rToken.Value == "(")
{
nCount++;
}
else if (rToken.Value == ")")
{
nCount--;
}
if ((rToken.Value == "," && nCount == 0) || rToken.Type == ExpressionToken.eType.End)
{
if (rListParameter.Count > 0)
{
var rResolve = new ExpressionResolve(rListParameter.ToArray());
var rExpression = rResolve.Resolve();
// 添加到参数列表中
rFunction.Parameter.Add(rExpression);
rListParameter.Clear();
}
}
else
{
rListParameter.Add(rToken);
}
}
if (nCount != 0)
{
throw new Exception("方法（ )不匹配");
}
e = rFunction;
return(true);
}