private ExpressionAST ParseBinOpRHS(int expressionPrecedence, ExpressionAST LHS)
{
while (true)
{
int tokenPrecedence = GetPrecedence(parser.LastToken);
if (tokenPrecedence < expressionPrecedence)
{
return(LHS);
}
string _operator = parser.LastToken.Value;
parser.ProceedToken(); // 演算子を消費
var RHS = ParsePrimary();
RHS.IsReturnValueUsed = true;
int nextPrecedence = GetPrecedence(parser.LastToken);
if (tokenPrecedence < nextPrecedence)
{
RHS = ParseBinOpRHS(tokenPrecedence + 1, RHS);
}
LHS = new BinaryExpressionAST(LHS, RHS, _operator);
}
}
internal BinaryExpressionAST(ExpressionAST LHS,
ExpressionAST RHS,
string _operator)
{
this.LHS = LHS;
this.RHS = RHS;
this._operator = _operator;
ReturnType = LHS.ReturnType;
}
