急！！一个有关计算公式的问题。。。(200分)

对hcm0790：你告诉我的那个方法出了点问题，呵呵 说是SQRT类型步匹配，不知道是什么原因啊，请教了

楼主啊, 不会在这个论坛看看我的帖子吗? 前面提醒过你, 简单的事情, 要那么复杂干吗?

新世纪：您说的是哪个帖子阿？不好意思哦 没看到 呵呵
对hcm0790：当用co.Language := 'VBScript';时报错提示 SQRT类型步匹配，当用co.Language := 'JavaScript';时，报错提示缺少对象，这应该怎么改啊？谢谢了

现在的问题是，比方说sin(X)这个式子，我从数据库里拿出来是string型的，怎么把它转换成公式让它计算啊？

unit UCxParser;
{==========================================================================}
{ Expression Evaluator v1.4 for Delphi }
{ Copyright ?1997 by BitSoft Development, L.L.C. }
{ Modify by zzy }
{ Modify by linhw }
{ 1、增加了中文函数的支持 }
{ 增加函数Asin,Acos,Tan }
{ 2、增加对符号处理 }
{ 中括号为注释 }
{ 花括号与括号相同 }
{ 3、大符号支持 +-*/ }
{==========================================================================}
interface
uses
Windows,
SysUtils, Messages, Classes, Graphics, Controls, Forms, Dialogs;
type
TGetVarEvent = procedure(Sender: TObject;
VarName: string;
var
Value: Extended;
var Found: Boolean) of object;
TParseErrorEvent = procedure(Sender: TObject;
ParseError: Integer)
of object;
const
ParserStackSize = 60;
MaxFuncNameLen = 8;
ExpLimit = 11356;
SqrLimit = 1E2466;
MaxExpLen = 6;
TotalErrors = 7;
ErrParserStack = 1;
ErrBadRange = 2;
ErrExpression = 3;
ErrOperator = 4;
ErrOpenParen = 5;
ErrOpCloseParen = 6;
ErrInvalidNum = 7;
type
ErrorRange = 0..TotalErrors;
TokenTypes = (Plus, Minus, Times, Divide, Expo, OParen, CParen, Num,
Func, EOL, Bad, ERR, Modu,Iif);
TokenRec = record
State: Byte;
case Byte of
0: (Value: Extended);
2: (FuncName: string[MaxFuncNameLen]);
end;

type
TCxParser = class(TComponent)
private
FInput: string;
FOnGetVar: TGetVarEvent;
FOnParseError: TParseErrorEvent;
protected
CurrToken: TokenRec;
MathError: Boolean;
Stack: array[1..ParserStackSize] of TokenRec;
StackTop: 0..ParserStackSize;
TokenError: ErrorRange;
TokenLen: Word;
TokenType: TokenTypes;
procedure OmitMemo;
function GetNextchar(aindex: integer): char;
function GotoState(Production: Word): Word;
function IsFunc(S: string): Boolean;
function IsVar(var Value: Extended): Boolean;
function NextToken: TokenTypes;
procedure Push(Token: TokenRec);
procedure Pop(var Token: TokenRec);
procedure Reduce(Reduction: Word);
procedure Shift(State: Word);
function IsCalChar(AIndex: integer): char;
public
Position: Word;
ParseError: Boolean;
ParseValue: Extended;
constructor Create;
procedure Parse;
published
property OnGetVar: TGetVarEvent read FOnGetVar write FOnGetVar;
property OnParseError: TParseErrorEvent read FOnParseError
write FOnParseError;
property ParseString: string read FInput write FInput;
end;

implementation
uses
math;
const
Letters: set of Char = ['<', 'A'..'Z', 'a'..'z'];
Numbers: set of Char = ['0'..'9'];
const
cCharCn: array[#32..#126] of string[2] =
(
{ }'　', {!} '！', {"} '＂', {#} '＃', { } '＄', {%} '％', {&amp;} '＆', {'}
'＇', {(} '（',
{)}'）', {*} '＊', {+} '+', {,} ',', {-} '－', {.} '。', {/} '／', {0} '０',
{1}'１',
{2}'２', {3} '３', {4} '４', {5} '５', {6} '６', {7} '７', {8} '８', {9}
'９', {:} ':',
{;}';', {<} '＜', {=} '＝', {>} '＞', {?} '？', {@} '＠', {A} 'Ａ', {B}
'Ｂ',
{C}'Ｃ',
{D}'Ｄ', {E} 'Ｅ', {F} 'Ｆ', {G} 'Ｇ', {H} 'Ｈ', {I} 'Ｉ', {J} 'Ｊ', {K}
'Ｋ', {L} 'Ｌ',
{M}'Ｍ', {N} 'Ｎ', {O} 'Ｏ', {P} 'Ｐ', {Q} 'Ｑ', {R} 'Ｒ', {S} 'Ｓ', {T}
'Ｔ', {U} 'Ｕ',
{V}'Ｖ', {W} 'Ｗ', {X} 'Ｘ', {Y} 'Ｙ', {Z} 'Ｚ', {[} '［', {/} '＼', {]}
'］', {^} '＾',
{_}'＿', {`} '｀', {a} 'ａ', {b} 'ｂ', {c} 'ｃ', {d} 'ｄ', {e} 'ｅ', {f}
'ｆ', {g} 'ｇ',
{h}'ｈ', {i} 'ｉ', {j} 'ｊ', {k} 'ｋ', {l} 'ｌ', {m} 'ｍ', {n} 'ｎ', {o}
'ｏ', {p} 'ｐ',
{q}'ｑ', {r} 'ｒ', {s} 'ｓ', {t} 'ｔ', {u} 'ｕ', {v} 'ｖ', {w} 'ｗ', {x}
'ｘ', {y} 'ｙ',
{z}'ｚ', {{} '｛', {|} '｜', { } '｝', {~} '～');
function GBTextToStr(mText: string): string;
{ 返回字符串转换成半角字符串 }
var
I: Integer;
J: Char;
S: string;
begin
Result := '';
for I := 1 to Length(WideString(mText))do
begin
S := WideString(mText);
if Length(S) > 1 then
begin
for J := #32 to #126do
if cCharCn[J] = S then
begin
S := J;
Break;
end;
if S = '．' then
S := '.';
end;
Result := Result + S;
end;
end;
{ GBTextToStr }
constructor TCxParser.Create;
begin
// inherited Create(AOwner);
{ defaults }
FInput := '';
end;

function TCxParser.GotoState(Production: Word): Word;
{ Finds the new state based on the just-completed production and the
top state. }
var
State: Word;
begin
GotoState := 0;
State := Stack[StackTop].State;
if (Production <= 3) then
begin
case State of
0: GotoState := 1;
9: GotoState := 19;
20: GotoState := 28;
end;
{ case }
end
else
if Production <= 6 then
begin
case State of
0, 9, 20: GotoState := 2;
12: GotoState := 21;
13: GotoState := 22;
end;
{ case }
end
else
if (Production <= 8) or (Production = 100) then
begin
case State of
0, 9, 12, 13, 20: GotoState := 3;
14: GotoState := 23;
15: GotoState := 24;
16: GotoState := 25;
40: GotoState := 80;
end;
{ case }
end
else
if Production <= 10 then
begin
case State of
0, 9, 12..16, 20, 40: GotoState := 4;
end;
{ case }
end
else
if Production <= 12 then
begin
case State of
0, 9, 12..16, 20, 40: GotoState := 6;
5: GotoState := 17;
end;
{ case }
end
else
begin
case State of
0, 5, 9, 12..16, 20, 40: GotoState := 8;
end;
{ case }
end;
end;
{ GotoState }
function TCxParser.IsFunc(S: string): Boolean;
{ Checks to see if the parser is about to read a function }
var
P, SLen: Word;
FuncName: string;
begin
P := Position;
FuncName := '';
while (P <= Length(FInput)) and (FInput[P] in ['A'..'Z', 'a'..'z', '0'..'9',
'_']) or (bytetype(FInput, P) <> mbSingleByte)do
//Add by zzy加入中文函数处理
begin
FuncName := FuncName + FInput[P];
Inc(P);
end;
{ while }
if Uppercase(FuncName) = S then
begin
SLen := Length(S);
CurrToken.FuncName := UpperCase(Copy(FInput, Position, SLen));
Inc(Position, SLen);
IsFunc := True;
end { if }
else
IsFunc := False;
end;
{ IsFunc }
function TCxParser.IsVar(var Value: Extended): Boolean;
var
VarName: string;
VarFound: Boolean;
begin
VarFound := False;
VarName := '';
while (Position <= Length(FInput))do
begin
VarName := VarName + FInput[Position];
Inc(Position);
if Finput[Position - 1] = '>' then
break;
end;
{ while }
if Assigned(FOnGetVar) then
FOnGetVar(Self, VarName, Value, VarFound);
IsVar := VarFound;
end;
{ IsVar }
function GetNumS(S, SubS: string): Integer;
{某个字符串中子串的个数}
var
s1, s2: string;
{某个字符串中子串的个数}
begin
{注意最后一个不是subs时直接调用GetNums}
result := -1;
if s = '' then
exit;
s1 := stringreplace(s, subs, '

谢谢各位了 我再试试看 呵呵 只要留言的都分点分吧 以示对大家的感谢

对人在昆明：请问你给出的这个单元 我应该调用哪个函数来实现把我那个公式字符串变成可执行的公式啊？我看了一遍没看出来 呵呵

对人在昆明：请问你给出的这个单元 我应该调用哪个函数来实现把我那个公式字符串变成可执行的公式啊？我看了一遍没看出来 呵呵
对hcm0790，你给的方法对sin什么的函数都可以，但是对sqrt和int之类的好像不行啊 不怎么支持。拜托帮我看一下吧

去查一下javascript 的语法就行了