Парсинг строк
Материал из DRKB
Парсинг строк[править | править код]
unit splitfns;
interface
uses Classes, Sysutils;
{ Returns the next token (substring) from string S, starting at index StartPos and ending 1 character
before the next occurrence of Separator (or at the end of S, whichever comes first).
StartPos - returns the starting position for the next token, 1 more than the position in S of
the end of this token }
function GetNextToken(Const S: string; Separator: TSysCharSet; var StartPos: integer): String;
{ Splits a string containing designated separators into tokens and adds them to MyStringList NOTE: MyStringList must be Created before being passed to this procedure and Freed after use }
procedure Split(const S: String; Separator: TSysCharSet; MyStringList: TStringList);
{ Used to join 2 strings with a separator character between them and can be used in a Join function
The StringLimit parameter prevents the length of the Result String from exceeding a preset maximum }
function AddToken (const aToken, S: String; Separator: Char; StringLimit: integer): String;
implementation
function GetNextToken(Const S: string; Separator: TSysCharSet; var StartPos: integer): String;
var
Index: integer;
begin
Result := '';
{ Step over repeated separators }
while (S[StartPos] in Separator) and (StartPos <= Length(S)) do
StartPos := StartPos + 1;
if StartPos > length(S) then Exit;
{ Set Index to StartPos }
Index := StartPos;
{ Find the next Separator }
while not (S[Index] in Separator) and (Index <= Length(S)) do
Index := Index + 1;
{ Copy the token to the Result }
Result := Copy(S, StartPos, Index - StartPos);
{ SetStartPos to next Character after the Separator }
StartPos := Index + 1;
end;
procedure Split(const S: String; Separator: TSysCharSet; MyStringList: TStringList);
var
Start: integer;
begin
Start := 1;
while Start <= Length(S) do
MyStringList.Add(GetNextToken(S, Separator, Start));
end;
function AddToken(const aToken, S: String; Separator: Char; StringLimit: integer): String;
begin
if Length(aToken) + Length(S) < StringLimit then
begin
{ Add a separator unless the Result string is empty }
if S = '' then Result := '' else Result := S + Separator;
{ Add the token }
Result := Result + aToken;
end
else
{ if the StringLimit would be exceeded, raise an exception }
Raise Exception.Create('Cannot add token');
end;
end.
пример использования:
data := TStringList.Create();
splited := TStringList.Create();
data.LoadFromFile(s);
Split(data.Text, [',', ' ', #10, #13, ';', '\"', '.', '!', '-', '+', '*', '/', '\',
'(', ')', '[', ']', '{', '}', '<', '>', '''', '"', '?', '"', '#', #0], splited);
for i:= 0 to splited.Count-1 do
begin
if not words.Find(splited.Strings,adr) then
words.Add(splited.Strings[i]);
Application.ProcessMessages(); // make program to respond to user
// commands while processing in case of very long string.
end;
Author: Song
Source: Взято из http://forum.sources.ru
ID: 00150
Некоторое время назад одна любезная душа прислала мне этот модуль. Я нашел его весьма полезным, но применять его вам надлежит с некоторой долей осторожности, ибо тэг %s иногда приводит к исключительным ситуациям.
unit Scanf;
interface
uses SysUtils;
type
EFormatError = class(ExCeption);
function Sscanf(const s: string; const fmt: string;
const Pointers: array of Pointer): Integer;
implementation
{ Sscanf выполняет синтаксический разбор входной строки. Параметры...
s - входная строка для разбора
fmt - 'C' scanf-форматоподобная строка для управления разбором
%d - преобразование в Long Integer
%f - преобразование в Extended Float
%s - преобразование в строку (ограничено пробелами)
другой символ - приращение позиции s на "другой символ"
пробел - ничего не делает
Pointers - массив указателей на присваиваемые переменные
результат - количество действительно присвоенных переменных
Например, ...
Sscanf('Name. Bill Time. 7:32.77 Age. 8',
'. %s . %d:%f . %d', [@Name, @hrs, @min, @age]);
возвратит ...
Name = Bill hrs = 7 min = 32.77 age = 8 }
function Sscanf(const s: string; const fmt: string;
const Pointers: array of Pointer): Integer;
var
i, j, n, m: integer;
s1: string;
L: LongInt;
X: Extended;
function GetInt: Integer;
begin
s1 := '';
while (s[n] = ' ') and (Length(s) > n) do
inc(n);
while (s[n] in ['0'..'9', '+', '-'])
and (Length(s) >= n) do
begin
s1 := s1 + s[n];
inc(n);
end;
Result := Length(s1);
end;
function GetFloat: Integer;
begin
s1 := '';
while (s[n] = ' ') and (Length(s) > n) do
inc(n);
while (s[n] in ['0'..'9', '+', '-', '.', 'e', 'E'])
and (Length(s) >= n) do
begin
s1 := s1 + s[n];
inc(n);
end;
Result := Length(s1);
end;
function GetString: Integer;
begin
s1 := '';
while (s[n] = ' ') and (Length(s) > n) do
inc(n);
while (s[n] <> ' ') and (Length(s) >= n) do
begin
s1 := s1 + s[n];
inc(n);
end;
Result := Length(s1);
end;
function ScanStr(c: Char): Boolean;
begin
while (s[n] <> c) and (Length(s) > n) do
inc(n);
inc(n);
if (n <= Length(s)) then
Result := True
else
Result := False;
end;
function GetFmt: Integer;
begin
Result := -1;
while (TRUE) do
begin
while (fmt[m] = ' ') and (Length(fmt) > m) do
inc(m);
if (m >= Length(fmt)) then
break;
if (fmt[m] = '%') then
begin
inc(m);
case fmt[m] of
'd': Result := vtInteger;
'f': Result := vtExtended;
's': Result := vtString;
end;
inc(m);
break;
end;
if (ScanStr(fmt[m]) = False) then
break;
inc(m);
end;
end;
begin
n := 1;
m := 1;
Result := 0;
for i := 0 to High(Pointers) do
begin
j := GetFmt;
case j of
vtInteger:
begin
if GetInt > 0 then
begin
L := StrToInt(s1);
Move(L, Pointers[i]^, SizeOf(LongInt));
inc(Result);
end
else
break;
end;
vtExtended:
begin
if GetFloat > 0 then
begin
X := StrToFloat(s1);
Move(X, Pointers[i]^, SizeOf(Extended));
inc(Result);
end
else
break;
end;
vtString:
begin
if GetString > 0 then
begin
Move(s1, Pointers[i]^, Length(s1) + 1);
inc(Result);
end
else
break;
end;
else
break;
end;
end;
end;
end.
Source: http://delphiworld.narod.ru/
ID: 00909
// Parse a string, for example:
// How do I get the "B" from "A|B|C|D|E|F"?
function Parse(Char, S: string; Count: Integer): string;
var
I: Integer;
T: string;
begin
if S[Length(S)] <> Char then
S := S + Char;
for I := 1 to Count do
begin
T := Copy(S, 0, Pos(Char, S) - 1);
S := Copy(S, Pos(Char, S) + 1, Length(S));
end;
Result := T;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(Parse('|', 'A|B|C|D|E|F', 2));
end;
{
Parameters:
Parse([Character, for example "|"], [The string],
[The number, the "B" is the 2nd part of the string]);
This function is handy to use when sending data over the internet,
for example a chat program: Name|Text. Note: Be sure there's no "Char" in the string!
Use a unused character like "|" or "?".
}
Source: Взято с сайта: http://www.swissdelphicenter.ch
ID: 00910