// 执行call操作
private object applyCallOperator(string Identifier, string IdentifierLower, ASTNode_ArgList Args, int LineNumber)
{
object pNativeFunc = fetchValueOfIdentifier(Identifier, IdentifierLower, LineNumber);
if (pNativeFunc is NativeCallHandler == false)
{
throw new RuntimeException(LineNumber, String.Format("\"{0}\" is not callable.", Identifier));
}
NativeCallHandler pHandler = (NativeCallHandler)pNativeFunc;
object[] pArgs = null;
if (Args.Args.Count > 0)
{
pArgs = new object[Args.Args.Count];
for (int i = 0; i < Args.Args.Count; ++i)
{
// 计算参数
pArgs[i] = ExecExpression(Args.Args[i]);
}
}
// 调用函数
return(pHandler(this, pArgs, LineNumber));
}
/// <summary>
/// 解析一个ArgList
/// </summary>
/// <param name="Lex">词法分析器</param>
/// <returns>解析结果</returns>
private static ASTNode_ArgList ParseArgList(Lexer Lex)
{
ASTNode_ArgList tRet = new ASTNode_ArgList();
if (Lex.CurrentToken != Lexer.Token.RightBracket) // 非空arglist
{
while (true)
{
tRet.Args.Add(ParseExpression(Lex));
if (TryMatchToken(Lex, Lexer.Token.Comma)) // ','
{
continue;
}
else if (Lex.CurrentToken == Lexer.Token.RightBracket) // peek ')'
{
break;
}
else
{
throw new SyntaxException(Lex.Position, Lex.Line, Lex.Row,
String.Format("unexpected token {0}.", Lex.FormatCurrentToken()));
}
}
}
return(tRet);
}
/// <summary>
/// 解析原子表达式
/// </summary>
/// <param name="Lex">词法分析器</param>
/// <returns>解析结果</returns>
private static ASTNode_Expression ParseAtomExpression(Lexer Lex)
{
ASTNode_Expression tRet;
if (Lex.CurrentToken == Lexer.Token.DigitLiteral) // digit_literal
{
tRet = new ASTNode_DigitLiteral(Lex.Line, Lex.CurrentDigit);
Lex.Next();
return(tRet);
}
else if (Lex.CurrentToken == Lexer.Token.Identifier) // symbol or call_expression
{
string tIdentifier = MatchIdentifier(Lex);
// 检查下一个符号
if (TryMatchToken(Lex, Lexer.Token.LeftBracket)) // '(' -- call_expression
{
ASTNode_ArgList tArgList = ParseArgList(Lex);
MatchToken(Lex, Lexer.Token.RightBracket); // ')'
return(new ASTNode_CallExpression(Lex.Line, tIdentifier, tArgList));
}
else // symbol
{
return(new ASTNode_SymbolExpression(Lex.Line, tIdentifier));
}
}
else if (TryMatchToken(Lex, Lexer.Token.LeftBracket)) // '(' -- bracket_expression
{
tRet = ParseBracketExpression(Lex);
MatchToken(Lex, Lexer.Token.RightBracket); // ')'
return(tRet);
}
else
{
throw new SyntaxException(Lex.Position, Lex.Line, Lex.Row,
String.Format("unexpected token {0}.", Lex.FormatCurrentToken()));
}
}
public ASTNode_CallExpression(int LineNum, string Id, ASTNode_ArgList AL)
: base(ASTNode.ASTType.Call, LineNum)
{
Identifier = Id;
ArgList = AL;
}