/// <summary>
/// Exit a parse tree produced by <see cref="CMMParser.boolExpression"/>.
/// <para>The default implementation does nothing.</para>
/// </summary>
/// <param name="context">The parse tree.</param>
public virtual void ExitBoolExpression([NotNull] CMMParser.BoolExpressionContext context)
{
}
/// <summary>
/// Visit a parse tree produced by <see cref="CMMParser.boolExpression"/>.
/// <para>
/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
/// on <paramref name="context"/>.
/// </para>
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public virtual Result VisitBoolExpression([NotNull] CMMParser.BoolExpressionContext context)
{
return(VisitChildren(context));
}
/**
* 判断子表达式的值并压入栈中
*
*
*/
public override object VisitBoolExpression([NotNull] CMMParser.BoolExpressionContext context)
{
Object res = VisitChildren(context);
Double op1, op2;
if (context.ChildCount.Equals(3))
{
string relationalOperator = context.GetChild(1).GetText();
IntermediateCode code = new IntermediateCode(context.Start.Line);
switch (relationalOperator)
{
case "<=":
code.type = InstructionType.le;
// op1 = (Double)expStack.Pop();
// op2 = (Double)expStack.Pop();
// expStack.Push(op2 <= op1 ? 1 : 0);
break;
case ">=":
code.type = InstructionType.ge;
// op1 = (Double)expStack.Pop();
// op2 = (Double)expStack.Pop();
// expStack.Push(op2 >= op1 ? 1 : 0);
break;
case "==":
code.type = InstructionType.eq;
// op1 = (Double)expStack.Pop();
// op2 = (Double)expStack.Pop();
// expStack.Push(op2 == op1 ? 1 : 0);
break;
case "<":
code.type = InstructionType.l;
// op1 = (Double)expStack.Pop();
// op2 = (Double)expStack.Pop();
// expStack.Push(op2 < op1 ? 1 : 0);
break;
case ">":
code.type = InstructionType.g;
// op1 = (Double)expStack.Pop();
// op2 = (Double)expStack.Pop();
// expStack.Push(op2 > op1 ? 1 : 0);
break;
case "<>":
code.type = InstructionType.ne;
// op1 = (Double)expStack.Pop();
// op2 = (Double)expStack.Pop();
// expStack.Push(op2 != op1 ? 1 : 0);
break;
default:
break;
}
codes.Add(code);
}
else
{
// additiveExpression的情况不用处理 直接把值压栈
}
return(res);
}
