Changeset 17 for trunk

Timestamp:

Feb 11, 2012, 7:41:10 PM (13 years ago)

Author:

chronos

Message:

• Modified: Optimized brainfuck command Write.
• Added: All nonusable characters are removed before starting interpretter program.

File:

• trunk/UBrainFuck.pas (modified) (6 diffs)

trunk/UBrainFuck.pas

@@ -56 +56 @@
     procedure Write(Value: Byte);
     function Read: Byte;
-    function TryRead(Output: Byte): Boolean;
-    function ReadCode: Char;
     procedure SetThread(State: Boolean);
     procedure PrepareJumpTable;
+    procedure RemoveBlankCharacters;
   public
     FSource: array of Char;
@@ -68 +67 @@
     MemoryPosition: Integer;
     Output: string;
+    OutputPosition: Integer;
     Input: string;
     InputPosition: Integer;
@@ -115 +115 @@
 procedure TBrainFuckInterpretter.Write(Value: Byte);
 begin
-  Output := Output + Char(Value);
+  if OutputPosition > Length(Output) then
+    SetLength(Output, Length(Output) + 1 + Length(Output) div 4);
+  Output[OutputPosition] := Char(Value);
+  Inc(OutputPosition);
 end;
 
@@ -157 +160 @@
 function TBrainFuckInterpretter.Read: Byte;
 begin
-  while (InputPosition >= Length(Input)) and (FState <> rsStopped) do begin
+  while (InputPosition > Length(Input)) and (FState <> rsStopped) do begin
     Sleep(1);
   end;
-  if InputPosition < Length(Input) then begin
-    Result := Ord(Input[InputPosition + 1]);
+  if InputPosition <= Length(Input) then begin
+    Result := Ord(Input[InputPosition]);
     Inc(InputPosition);
   end else Result := 0;
-end;
-
-function TBrainFuckInterpretter.TryRead(Output: Byte): Boolean;
-begin
-  if InputPosition >= Length(Input) then Result := False
-  else begin
-    Output := Ord(Input[InputPosition + 1]);
-    Inc(InputPosition);
-    Result := True;
-  end;
-end;
-
-function TBrainFuckInterpretter.ReadCode: Char;
-begin
-  Result := FSource[SourcePosition];
 end;
 
@@ -224 +212 @@
 end;
 
+procedure TBrainFuckInterpretter.RemoveBlankCharacters;
+var
+  I: Integer;
+  LastChar: Integer;
+begin
+  LastChar := 0;
+  for I := 0 to Length(FSource) - 1 do
+    if FSource[I] in ['+','-','>','<','.',',','[',']'] then begin
+      FSource[LastChar] := FSource[I];
+      Inc(LastChar);
+    end;
+  SetLength(FSource, LastChar);
+end;
+
 procedure TBrainFuckInterpretter.Reset;
 var
   I: Integer;
 begin
+  RemoveBlankCharacters;
   PrepareJumpTable;
   SourcePosition := 0;
-  InputPosition := 0;
+  InputPosition := 1;
   Output := '';
+  OutputPosition := 1;
   MemoryPosition := 0;
   //FillChar(Pointer(Memory)^, Length(Memory), 0);
@@ -245 +249 @@
   NewPos: Integer;
 begin
-  case ReadCode of
+  case FSource[SourcePosition] of
     '>': if MemoryPosition < MemorySize then Inc(MemoryPosition)
       else raise Exception.Create(SProgramUpperLimit);