public void Visit(SubExpr subExpr, object[] args)
{
subExpr.FirstOp.Accept(this);
subExpr.SecondOp.Accept(this);
RightValue v1 = readRightValue(subExpr.FirstOp);
RightValue v2 = readRightValue(subExpr.SecondOp);
DataType resultType = readAlgoOperand(v1, v2, subExpr.Location);
if (resultType == DataType.Int)
{
IntConst result = new IntConst();
result.Value = Convert.ToInt32(v1.GetValueObject()) - Convert.ToInt32(v2.GetValueObject());
subExpr.RightValue = result;
//subExpr.DataType = DataType.Int;
}
else if (resultType == DataType.Float)
{
FloatConst result = new FloatConst();
result.Value = Convert.ToDouble(v1.GetValueObject()) - Convert.ToDouble(v2.GetValueObject());
subExpr.RightValue = result;
//subExpr.DataType = DataType.Float;
}
else
{
throw new Exception();
}
}
public static void Run()
{
var expression = new SubExpr <int>(new AddExpr <int>(new ValExpr <int>(2), new ValExpr <int>(2)), new ValExpr <int>(2));
var result = expression.Eval(algebra: (
add: (x, y) => x + y,
sub: (x, y) => x + y,
val: v => v)
);
}
static void Main(string[] args)
{
Console.WriteLine("1_______________________________________________________________________________");
// (3*x^2 + 7) / (x + 5) 82 / 10 = 8.2
Expression exp = new DivExpr(
new AddExpr(
MonomialExpr.createObject(3, 2),
ConstExpr.createObject(7)),
new AddExpr(
MonomialExpr.createObject(1, 1),
ConstExpr.createObject(5)));
Console.WriteLine("f(x)=" + exp.ToString());
Console.WriteLine("f(5)=" + exp.Evaluate(5));
Console.WriteLine("f'(x)=" + exp.Derive().ToString());
Console.WriteLine("2_______________________________________________________________________________");
// (0 + 10) - 0 * (x^1 + 0)
Expression exp5 = new AddExpr(MonomialExpr.createObject(0, 2),
ConstExpr.createObject(10));
Expression exp6 = new SubExpr(exp5,
new MulExpr(ConstExpr.createObject(0),
new AddExpr(MonomialExpr.createObject(1, 1),
ConstExpr.createObject(0))));
Console.WriteLine("f(x)=" + exp6.ToString());
Console.WriteLine("f(2)=" + exp6.Evaluate(2));
Console.WriteLine("f'(x)=" + exp6.Derive().ToString());
Console.WriteLine("3_______________________________________________________________________________");
//(((x^2 + 2) / (x + 1)) + 10) / (x^2 + 5)
Expression exp3 = new DivExpr(
new AddExpr(
MonomialExpr.createObject(1, 2),
ConstExpr.createObject(2)),
new AddExpr(
MonomialExpr.createObject(1, 1),
ConstExpr.createObject(1)));
Expression exp4 = new DivExpr(
new AddExpr(
exp3,
ConstExpr.createObject(10)),
new AddExpr(
MonomialExpr.createObject(1, 2),
ConstExpr.createObject(5)));
Console.WriteLine("f(x)=" + exp4.ToString());
Console.WriteLine("f(1)=" + exp4.Evaluate(1));
Console.WriteLine("f'(x)=" + exp4.Derive().ToString());
}
private Expr parseAddExpr()
{
Expr expr = parseMulExpr();
while (true)
{
int token = parseToken();
switch (token)
{
case '+':
expr = new AddExpr(expr, parseMulExpr());
break;
case '-':
expr = new SubExpr(expr, parseMulExpr());
break;
default:
_peekToken = token;
return(expr);
}
}
}
/// <summary>
/// Validate a subtraction expression.
/// </summary>
/// <param name="subex">
/// is the expression. </param>
/// <returns> null. </returns>
public virtual object visit(SubExpr subex)
{
printBinExpr("SUB", subex);
return(null);
}
//--------------------------------------------------------------------
#region 内部方法
ExprBase Parse(Queue <string> stringQueue)
{
string word = null;
ExprBase first = null, prev = null, last = null;
while (stringQueue.Count > 0)
{
word = stringQueue.Dequeue();
if (word == "(")
{
ExprBase subExpr = Parse(stringQueue);
if (subExpr == null)
{
return(null);
}
last = new SubExpr(subExpr);
}
else if (word[0] == '\'')
{
int endPos = word.LastIndexOf('\'');
if (endPos > 0)
{
last = new StrExpr(word.Substring(1, endPos - 1));
}
else
{
return(null);
}
}
else if (word[0] == '\"')
{
int endPos = word.LastIndexOf('\"');
if (endPos > 0)
{
last = new StrExpr(word.Substring(1, endPos - 1));
}
else
{
return(null);
}
}
else if (word == "true")
{
last = new ConstExpr(1);
}
else if (word == "false")
{
last = new ConstExpr(0);
}
else if (word[0] == '-' || Char.IsDigit(word[0]))
{
if (word.Contains("."))
{
last = new ConstExpr(float.Parse(word));
}
else
{
last = new ConstExpr(int.Parse(word));
}
}
else
{
last = ParseFunc(word, stringQueue);
}
if (last == null)
{
return(null);
}
if (first == null)
{
first = prev = last;
}
else
{
prev.next = last;
prev = last;
}
// 条件连接关系
if (stringQueue.Count > 0)
{
word = stringQueue.Dequeue();
if (word == ")")
{
break;
}
last.connector = ExprConnectors.Get(word);
if (last.connector == null)
{
return(null);
}
}
last = null;
}
return(first);
}
/// <param name="ex">
/// is the sub expression. </param>
/// <returns> a new function. </returns>
public virtual object visit(SubExpr ex)
{
ex.left().accept(this);
ex.right().accept(this);
return(null);
}
/// <param name="e">
/// is the minus expression. </param>
/// <returns> new sub expression </returns>
public virtual object visit(MinusExpr e)
{
SubExpr se = new SubExpr(make_int_lit(0), e.arg());
return(se.accept(this));
}
/// <param name="subex">
/// is the sub expression. </param>
/// <returns> a new function. </returns>
public virtual object visit(SubExpr subex)
{
return(make_ArithOp(subex, new QName("fs", "minus", OpFunctionLibrary.XPATH_OP_NS)));
}
