继续表达式求值—支持函数

-------------------AS如下------------------
var ostr = "+,-,*,/,%,^";
var fstr = "sin,cos,max,min";
//获取运算符的优先级，非运算符的优先级为0
function isp(optr:String) {
switch (optr) {
case "+" :
case "-" :
return 1;
case "*" :
case "/" :
case "%" :
return 2;
case "^" :
return 3;
default :
return 0;
}
}
//判断操作数的类型(数字或变量)并作相应处理
function getNum(str:String) {
var ch = str.substr(0, 1);
if ((ch<"0" || ch>"9") && ch != "-") {
return eval(str);
} else {
return Number(str);
}
}
//运算符的具体运算
function func(optr:String, va:Array) {
for (var i in va) {
va[i] = getNum(va[i]);
}
switch (optr) {
case "+" :
return va[0]+va[1];
case "-" :
return va[0]-va[1];
case "*" :
return va[0]*va[1];
case "/" :
return va[0]/va[1];
case "%" :
return va[0]%va[1];
case "^" :
return Math.pow(va[0], va[1]);
case "sin" :
return Math.sin(va[0]/180*Math.PI);
case "cos" :
return Math.cos(va[0]/180*Math.PI);
case "max" :
return Math.max(va[0], va[1]);
case "min" :
return Math.min(va[0], va[1]);
}
}
//找出最里层的括号,并返回括号的起始位置及括号内的表达式
function godepth(estr) {
var e = estr.indexOf(")");
var s = estr.lastIndexOf("(", e);
estr = estr.slice(s+1, e);
var obj = {s:s, e:e, estr:estr};
return obj;
}
//计算带括号和函数的表达式
function toNum2(estr, ostr, fstr) {
var i, JHTEMP, obj = godepth(estr), hasfunc = "";
fstr = fstr.split(",");
while (obj.s>=0 && obj.e>obj.s) {
JHTEMP = toNum1(obj.estr, ostr);
//检查左括号的外边是否是一个函数名
for (i in fstr) {
if (estr.lastIndexOf(fstr[i], obj.s) == obj.s-fstr[i].length) {
hasfunc = fstr[i];
break;
}
}
if (hasfunc.length>0) {
JHTEMP = func(hasfunc, JHTEMP);
estr = estr.slice(0, obj.s-hasfunc.length)+JHTEMP+estr.slice(obj.e+1);
hasfunc = "";
} else {
JHTEMP = JHTEMP[0];
estr = estr.slice(0, obj.s)+"JHTEMP"+estr.slice(obj.e+1);
}
obj = godepth(estr);
}
estr = toNum1(estr, ostr);
return estr;
}
//计算无括号带逗号表达式
function toNum1(estr, ostr) {
var i, earray = estr.split(",");
for (i in earray) {
earray[i] = toNum0(earray[i], ostr);
}
return earray;
}
//计算无括号无逗号表达式
function toNum0(estr:String, ostr:String) {
var i, maxisp, earray = toArray0(estr, ostr);
//搜索数组，找出最高的优先级(非运算符的优先级为0)
while (earray.length>1) {
maxisp = 0;
for (i in earray) {
maxisp = Math.max(maxisp, isp(earray[i]));
}
//从左往右搜索优先级最高的第一个运算符并计算
for (i=0; i<earray.length; i++) {
if (maxisp>0 && isp(earray[i]) == maxisp) {
var va = [earray[i-1], earray[i+1]];
earray.splice(i-1, 3, func(earray[i], va));
break;
}
}
}
return getNum(earray[0]);
}
//分解无括号无逗号表达式字串
function toArray0(estr, ostr) {
ostr = ostr.split(",");
var index = [], i, temp;
//搜索表达式字串中的所有运算符并记录其位置和长度
for (i in ostr) {
temp = -1;
while ((temp=estr.indexOf(ostr[i], temp+1)) != -1) {
if (!(ostr[i] == "-" && temp == 0)) {
var L = index.length;
index[L] = [];
index[L][0] = temp;
index[L][1] = ostr[i].length;
}
}
}
function compareFunction(A, B) {
return A[0]>B[0] ? 1 : A[0]<B[0] ? -1 : 0;
}
index.sort(compareFunction);
temp = estr;
var s = 0, e;
estr = [];
//将字串分解为元素并按顺序存储到数组里
for (i=0; i<index.length; i++) {
e = index[i][0];
estr.push(temp.slice(s, e));
s = e+index[i][1];
estr.push(temp.slice(e, s));
}
estr.push(temp.slice(s));
return estr;
}
//=============测试============
var m = 20;
var n = 4;
var x = 100;
var y = 3;
var estr = "max(2,min(3,4))-sin(30)+m*n+m/n";
var TF = new TextFormat();
TF.align = "center";
this.createTextField("hello", 1, 0, 25, 400, 20);
with (hello) {
type = "dynamic";
selectable = false;
setNewTextFormat(TF);
text = "输入表达式后按ENTER开始计算";
}
this.createTextField("in_out", 2, 2, 50, 396, 20);
with (in_out) {
type = "input";
border = true;
restrict = "A-Za-z0-9+*/%()=.,\\-\\^";
setNewTextFormat(TF);
in_out.text = estr+"="+toNum2(estr, ostr, fstr);
}
function out() {
var estr = in_out.text;
var e = estr.lastIndexOf("=");
if (e == -1) {
e = estr.length;
}
estr = estr.slice(0, e);
in_out.text = estr+"="+toNum2(estr, ostr, fstr);
}
this.onMouseUp = function() {
Selection.setSelection(0, in_out.length);
};
in_out.onKillFocus = out;
var myListener = new Object();
Key.addListener(myListener);
myListener.onKeyDown = function() {
if (Key.isDown(Key.ENTER)) {
out();
}
};
new _jh7086();