Exp parseTerm()
{
//report("parseTerm");
Exp leftExp = null;
if (TokenKindHelper.IsLiteral(tape.CurrentKind))// CurrentToken.IsLiteral())
{
leftExp = parseLiteral();
}
else if (tape.CurrentKind == TokenKind.Each)
{
ExpEachWord varExp = new ExpEachWord();
varExp.EachToken = tape.Current;
tape.MoveNext();
return(varExp);
}
else if (tape.Current.IsTypeName())
{
leftExp = parseTypeExp();
return(leftExp);
}
else if (tape.Current.IsProcPart())
{
leftExp = parseProcNamePart();
return(leftExp);
}
else if (tape.Current.IsVarName())
{
leftExp = parseVarExp();
return(leftExp);
}
else if (tape.Current.Kind == TokenKind.Ident)
{
leftExp = parseVarExp();
return(leftExp);
}
else if (tape.Current.Kind == TokenKind.LBS)
{
leftExp = parseBracket();
return(leftExp);
}
else if (tape.Current.Kind == TokenKind.RBS)
{
tape.error("多余的右括号");
tape.MoveNext();
return(null);
}
else if (tape.Current.WKind == WordKind.Unkown)
{
var currentText = tape.Current.GetText();
tape.error("无法识别'" + currentText + "'");
tape.MoveNext();
return(null);
}
return(leftExp);
}
protected Exp parseCompareExpr()
{
Token opToken;
Exp resultExpr = parseAddSub();
//while (CurrentToken.Kind == TokenKind.GT || CurrentToken.Kind == TokenKind.LT || CurrentToken.Kind == TokenKind.GE
// || CurrentToken.Kind == TokenKind.LE || CurrentToken.Kind == TokenKind.NE || CurrentToken.Kind == TokenKind.EQ)
while (TokenKindHelper.IsCompareOp(tape.CurrentKind))
{
opToken = tape.Current;
tape.MoveNext();
Exp rightExpr = parseAddSub();
resultExpr = new ExpBinary()
{
LeftExp = resultExpr, OpToken = opToken, RightExp = rightExpr
};
}
return(resultExpr);
}
Exp parseCall()
{
//report("parseCall");
List <Exp> exps = new List <Exp>();
while (tape.Current.Kind == TokenKind.Ident || tape.Current.Kind == TokenKind.LBS || TokenKindHelper.IsLiteral(tape.Current.Kind))//|| CurrentKind == TokenKind.RBS
{
Exp term = parseChain();
exps.Add(term);
}
if (exps.Count == 2 && (exps[0] is ExpType) && (exps[1] is ExpBracket))
{
ExpNew expNew = new ExpNew();
expNew.TypeExp = (exps[0] as ExpType);
expNew.BracketExp = (exps[1] as ExpBracket);
return(expNew);
}
else if (exps.Count == 0)
{
return(null);
}
else if (exps.Count == 1 && !(exps[0] is ExpProcNamePart))
{
return(exps[0]);
}
else
{
ExpCall callExp = new ExpCall();
callExp.Elements = exps;
return(callExp);
}
}
