| 0,0 → 1,122 |
|---|
| unit AlphaNumSort; |
| |
| (* |
| * The Alphanum Algorithm is an improved sorting algorithm for strings |
| * containing numbers. Instead of sorting numbers in ASCII order like |
| * a standard sort, this algorithm sorts numbers in numeric order. |
| * |
| * The Alphanum Algorithm is discussed at http://www.DaveKoelle.com |
| * |
| * Translated from Java to Delphi by Daniel Marschall, www.daniel-marschall.de |
| * Revision 2015-09-30 |
| * |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| * |
| *) |
| |
| interface |
| |
| uses |
| SysUtils; |
| |
| function AlphaNumCompare(s1, s2: string): integer; |
| |
| implementation |
| |
| function isDigit(ch: char): boolean; |
| begin |
| result := (ord(ch) >= 48) and (ord(ch) <= 57); |
| end; |
| |
| // Length of string is passed in for improved efficiency (only need to calculate it once) |
| function getChunk(s: string; slength, marker: integer): string; |
| var |
| chunk: string; |
| c: char; |
| begin |
| c := s[marker+1]; |
| chunk := chunk + c; |
| Inc(marker); |
| if isDigit(c) then |
| begin |
| while marker < slength do |
| begin |
| c := s[marker+1]; |
| if not isDigit(c) then break; |
| chunk := chunk + c; |
| Inc(marker); |
| end; |
| end |
| else |
| begin |
| while marker < slength do |
| begin |
| c := s[marker+1]; |
| if (isDigit(c)) then break; |
| chunk := chunk + c; |
| Inc(marker); |
| end; |
| end; |
| result := chunk; |
| end; |
| |
| function AlphaNumCompare(s1, s2: string): integer; |
| var |
| s1Length, s2Length, thisChunkLength: integer; |
| thisMarker, thatMarker, i: integer; |
| thisChunk, thatChunk: string; |
| begin |
| thisMarker := 0; |
| thatMarker := 0; |
| s1Length := Length(s1); |
| s2Length := Length(s2); |
| |
| while (thisMarker < s1Length) and (thatMarker < s2Length) do |
| begin |
| thisChunk := getChunk(s1, s1Length, thisMarker); |
| Inc(thisMarker, Length(thisChunk)); |
| |
| thatChunk := getChunk(s2, s2Length, thatMarker); |
| Inc(thatMarker, Length(thatChunk)); |
| |
| // If both chunks contain numeric characters, sort them numerically |
| if isDigit(thisChunk[1]) and isDigit(thatChunk[1]) then |
| begin |
| // Simple chunk comparison by length. |
| thisChunkLength := Length(thisChunk); |
| result := thisChunkLength - Length(thatChunk); |
| // If equal, the first different number counts |
| if result = 0 then |
| begin |
| for i := 0 to thisChunkLength-1 do |
| begin |
| result := ord(thisChunk[i+1]) - ord(thatChunk[i+1]); |
| if result <> 0 then Exit; |
| end; |
| end; |
| end |
| else |
| begin |
| result := CompareText(thisChunk, thatChunk); |
| end; |
| |
| if result <> 0 then Exit; |
| end; |
| |
| result := s1Length - s2Length; |
| end; |
| |
| end. |