unit AG.PascalTokenizer;
{$IFDEF FPC}
{$MODE Delphi}
{$ENDIF}

interface

uses
  SysUtils,Classes,IniFiles,SyncObjs,Generics.Collections;

type
  TAGTokenizerPos=record
    x,y:integer;
  end;

  TAGToken = record
    Text:string;
    &begin,&end:TAGTokenizerPos;
    ended:boolean;
    constructor Create(const Text:string;&begin,&end:TAGTokenizerPos;ended:boolean);
  end;

  TAGPasTokenizer=class
    strict protected
      FStrings:TStrings;
      FLineIx,x:integer;
      ended:boolean;
      procedure DoReadable();
      function IsReadable():boolean;
      procedure NextReadable();
      procedure SkipSpaces();
      function GetPos():TAGTokenizerPos;
      procedure SetPos(pos:TAGTokenizerPos);
    public
      constructor Create(input:TStrings);
      function GetNext():TAGToken;
      property pos:TAGTokenizerPos read GetPos write SetPos;
      property is_ended:boolean read ended;
  end;

  TAGPasTokenizerStack = class
    strict protected
      type
        GetCall=function(Tokenizer:TAGPasTokenizer):TAGToken of object;
      var
        Stack:TQueue<TAGToken>;
        Tokenizer:TAGPasTokenizer;
        Get:GetCall;
        IsEnd:boolean;
      function GetLast():TAGToken;virtual;
      function GetWithComments(Tokenizer:TAGPasTokenizer):TAGToken;
      function GetWithoutComments(Tokenizer:TAGPasTokenizer):TAGToken;
    protected
      function GetCachedCount:integer;inline;
    public
      constructor Create(input:TStrings;GetComments:boolean=True);
      procedure Push(const t:TAGToken);virtual;
      function Pop():TAGToken;virtual;
      destructor Destroy;override;
      property Last:TAGToken read GetLast write Push;
      property ended:boolean read IsEnd;
  end;

  TAGPasTokenizerParallelStack=class(TAGPasTokenizerStack)
    strict protected
      type
        TWorkerThread=class(TThread)
          strict protected
            FStack:TAGPasTokenizerParallelStack;
            procedure Execute;override;
          public
            Idling:boolean;
            constructor Create(const Stack:TAGPasTokenizerParallelStack);
        end;
    var
      FWorker:TWorkerThread;
      FStackLock:TCriticalSection;
      function AddTokenToStack:boolean;
      function GetLast():TAGToken;override;
      procedure EnsureThreadDone();
    protected
      FStackHalfMax:integer;
      FSignal:TEvent;
    public
      constructor Create(const input:TStrings;GetComments:boolean=True;stackMax:integer=1000);
      procedure Push(const t:TAGToken);override;
      function Pop():TAGToken;override;
      destructor Destroy;override;
  end;

function IsComment(s:string):boolean;
function IsName(s:string): boolean;
function IsString(const s:string): boolean;

implementation

const
  SYMS1='()[]/|\@#=><:;,.$+-*^';
  SPACES=#12#10#13#9#11' ';
  NO_NAME_SYMS=SYMS1+SPACES+'{}';
  CHARS_ID0='&abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_';
  CHARS_ID='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_';
  fix={$IFDEF NEXTGEN}-1{$ELSE}0{$ENDIF};

var
  SYMS2:THashedStringList;

function IsComment(s:string):boolean;
begin
Result:=s.startswith('{')or s.startswith('(*')or s.startswith('//');
end;

function IsName(s:string):boolean;
var
  i:integer;
begin
if(length(s)=0)or(s='&')or(not CHARS_ID0.Contains(s[1+fix]))then
  Exit(False);
for i:=2+fix to length(s)+fix do
  if not CHARS_ID.Contains(s[i])then
    Exit(False);
Result:=True;
end;

function IsString(const s:string):boolean;
begin
Result:=s.startswith(#39);
end;

{TAGToken}

constructor TAGToken.Create(const Text:string;&begin,&end:TAGTokenizerPos;ended:boolean);
begin
Self.Text:=Text;
Self.&begin:=&begin;
Self.&end:=&end;
Self.ended:=ended;
end;

{TAGPasTokenizer}

procedure TAGPasTokenizer.DoReadable();
begin
if not IsReadable()then
  if FLineIx+1=FStrings.Count then
    ended:=True
  else
  begin
    inc(FLineIx);
    x:=1+fix;
    while FStrings[FLineIx]<='' do
    begin
      if FLineIx+1=FStrings.Count then
      begin
        ended:=True;
        break;
      end;
      inc(FLineIx);
    end;
  end;
end;

function TAGPasTokenizer.IsReadable():boolean;
begin
Result:=x<=length(FStrings[FLineIx])+fix;
end;

procedure TAGPasTokenizer.NextReadable();
begin
inc(x);
DoReadable();
end;

procedure TAGPasTokenizer.SkipSpaces();
begin
DoReadable();
if not ended then
  while SPACES.Contains(FStrings[FLineIx][x])do
    NextReadable();
end;

function TAGPasTokenizer.GetPos():TAGTokenizerPos;
begin
Result.x:=x;
Result.y:=FLineIx;
end;

procedure TAGPasTokenizer.SetPos(pos:TAGTokenizerPos);
begin
FLineIx:=pos.x;
x:=pos.y;
ended:=False;
DoReadable();
end;

constructor TAGPasTokenizer.Create(input: TStrings);
begin
FStrings:=input;
FLineIx:=0;
x:=1+fix;
ended:=False;
SkipSpaces;
end;

{$WARN USE_BEFORE_DEF OFF}
function TAGPasTokenizer.GetNext():TAGToken;
var
  l,last_i0:integer;
  ml,ss,line:string;
  now_sym,next_sym:char;
  f:boolean;
  begin_pos:TAGTokenizerPos;
begin
  ml:='';
  ss:='';
  f:=True;
  begin_pos:=GetPos();
  while f and not ended do
  begin
    line:=FStrings[FLineIx];
    now_sym:=line[x];
    l:=length(line);
    if x<l+fix then
      next_sym:=line[x+1]
    else
      next_sym:=#0;

    if ml='' then
    begin
      if now_sym='/' then
        if next_sym='/' then
        begin
          ss:=Copy(line,x,l);
          x:=l+1+fix;
          break;
        end
      else if now_sym='{' then
      begin
        ml:='}';
        ss:=now_sym;
        last_i0:=FLineIx;
      end
      else if now_sym = '(' then
      begin
        if next_sym = '*' then
        begin
          ml:=')';
          inc(x);
          last_i0:=FLineIx;
          ss:=now_sym+next_sym;
        end
        else
        begin
          ss:='(';
          inc(x);
          break;
        end;
      end
      else
      begin
        if SYMS1.Contains(now_sym)then
        begin
          ss := now_sym;
          inc(x);
          if SYMS2.IndexOf(now_sym + next_sym)<>-1 then begin
            inc(x);
            ss := ss + next_sym;
          end;
          break;
        end
        else if now_sym = #39 then
        begin
          ss := #39;
          inc(x);
          if next_sym <> '' then
          begin
            ss := ss + next_sym;
            while line[x]<> #39 do
            begin
              inc(x);
              if not IsReadable()then
              begin
                dec(x);
                break;
              end;
              ss := ss + line[x];
            end;
            inc(x);
          end;
          break;
        end
        else
        begin
          while not NO_NAME_SYMS.Contains(line[x])do
          begin
            ss:=ss+line[x];
            inc(x);
            if not IsReadable()then
              break;
          end;
          break;
        end;
      end;
    end
    else
    begin
      while last_i0<>FLineIx do
      begin
        ss:=ss+#10;
        inc(last_i0);
      end;
      ss:=ss+now_sym;
      if now_sym=ml then
        if ml='}' then
        begin
          inc(x);
          break;
        end
        else if(x<>0)and(line[x - 1]='*')then
        begin
          inc(x);
          break;
        end;
    end;
    NextReadable();
  end;
  Result:=TAGToken.Create(ss,begin_pos,GetPos,ended);
  SkipSpaces();
end;
{$WARN USE_BEFORE_DEF ON}

{TAGPasTokenizerStack}

function TAGPasTokenizerStack.GetLast(): TAGToken;
begin
if Stack.Count<>0 then
  Result:=Stack.Peek
else
begin
  Result:=Get(Tokenizer);
  Stack.Enqueue(Result);
end;
end;

function TAGPasTokenizerStack.GetWithComments(Tokenizer:TAGPasTokenizer):TAGToken;
begin
Result:=Tokenizer.GetNext;
end;

function TAGPasTokenizerStack.GetWithoutComments(Tokenizer:TAGPasTokenizer):TAGToken;
begin
repeat
  Result:=Tokenizer.GetNext;
until Result.ended or not IsComment(Result.Text);
IsEnd:=Result.ended;
end;

function TAGPasTokenizerStack.GetCachedCount:integer;
begin
Result:=Stack.Count
end;

constructor TAGPasTokenizerStack.Create(input:TStrings;GetComments:boolean=True);
begin
Stack:=TQueue<TAGToken>.Create();
Tokenizer:=TAGPasTokenizer.Create(input);
if GetComments then
  Get:=GetWithComments
else
  Get:=GetWithoutComments;
end;

procedure TAGPasTokenizerStack.Push(const t: TAGToken);
begin
Stack.Enqueue(t);
end;

function TAGPasTokenizerStack.Pop():TAGToken;
begin
if Stack.Count>0 then
  Result:=Stack.Dequeue
else
  Result:=Get(Tokenizer);
IsEnd:=Result.ended;
end;

destructor TAGPasTokenizerStack.Destroy;
begin
FreeAndNil(Stack);
FreeAndNil(Tokenizer);
inherited;
end;

{TAGPasTokenizerParallelStack}

{TAGPasTokenizerParallelStack.TWorkerThread}

procedure TAGPasTokenizerParallelStack.TWorkerThread.Execute;
var
  Count,max:integer;
  isDone:boolean;
begin
Count:=FStack.GetCachedCount;
max:=FStack.FStackHalfMax*2;
repeat
  isDone:=FStack.AddTokenToStack();
  inc(Count);
  while not Terminated and(Count>=max)do
  begin
    Count:=FStack.GetCachedCount();
    if Count<max then
      break;
    Idling:=True;
    FStack.FSignal.WaitFor(1000);
    Count:=FStack.GetCachedCount();
  end;
  Idling:=False;
until Terminated or isDone or FStack.ended;
end;

constructor TAGPasTokenizerParallelStack.TWorkerThread.Create(const Stack:TAGPasTokenizerParallelStack);
begin
FStack:=Stack;
inherited Create(False{,4*4096});
end;

function TAGPasTokenizerParallelStack.AddTokenToStack():boolean;
var
  tkn:TAGToken;
begin
FStackLock.Enter;
tkn:=Get(Tokenizer);
Result:=tkn.ended;
Stack.Enqueue(tkn);
FStackLock.Leave;
end;

function TAGPasTokenizerParallelStack.GetLast:TAGToken;
begin
FStackLock.Enter;
try
  Result:=inherited GetLast();
finally
  FStackLock.Leave;
end;
end;

procedure TAGPasTokenizerParallelStack.EnsureThreadDone;
begin
if not FWorker.Terminated then
begin
  FWorker.Terminate;
  FSignal.SetEvent();
  FWorker.WaitFor();
end;
FreeAndNil(FWorker);
FreeAndNil(FSignal);
end;

constructor TAGPasTokenizerParallelStack.Create(const input:TStrings;GetComments:boolean=True;stackMax:integer=1000);
begin
inherited Create(input,GetComments);
FStackHalfMax:=stackMax shr 1;
FStackLock:=TCriticalSection.Create();
FSignal:=TEvent.Create(nil,False,True,'ag_tkn_work_signal');
FWorker:=TWorkerThread.Create(Self);
end;

procedure TAGPasTokenizerParallelStack.Push(const t:TAGToken);
begin
FStackLock.Enter;
try
  inherited Push(t);
finally
  FStackLock.Leave;
end;
end;

function TAGPasTokenizerParallelStack.Pop:TAGToken;
var
  doReplentishStack:boolean;
begin
FStackLock.Enter;

if Stack.Count > 0 then
  Result:=Stack.Dequeue
else
  Result:=Get(Tokenizer);

doReplentishStack:=FWorker.Idling and(Stack.Count<FStackHalfMax);
FStackLock.Leave;

IsEnd:=Result.ended;
if doReplentishStack then
  FSignal.SetEvent;
end;

destructor TAGPasTokenizerParallelStack.Destroy;
begin
EnsureThreadDone();
FreeAndNil(FStackLock);
inherited;
end;

initialization
SYMS2:=THashedStringList.Create();
SYMS2.Add('>=');
SYMS2.Add('<=');
SYMS2.Add('<>');
SYMS2.Add(':=');
SYMS2.Add('..');
SYMS2.Add('-=');
SYMS2.Add('+=');
SYMS2.Add('/=');
SYMS2.Add('*=');
SYMS2.Add('**');
SYMS2.Add('><');
SYMS2.Add('(.');
SYMS2.Add('.)');
SYMS2.Add('<<');
SYMS2.Add('>>');
finalization
FreeAndNil(SYMS2);
end.