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FR_Intrp.pas
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{******************************************}
{ }
{ FastReport CLX v2.4 }
{ Interpreter }
{ }
{ Copyright (c) 1998-2001 by Tzyganenko A. }
{ }
{******************************************}
unit FR_Intrp;
interface
{$I FR.inc}
uses Classes, SysUtils, FR_Pars;
type
// This is a simple Pascal-like interpreter. Input code can contain
// if-then-else, while-do, repeat-until, for, goto operators, begin-end blocks.
// Code can also contain expressions, variables, functions and methods.
// There is three events for handling variables and functions(methods):
// GetValue, SetValue and DoFunction.
// To execute code, call PrepareScript and then DoScript.
TfrInterpretator = class(TObject)
protected
FParser: TfrParser;
public
constructor Create;
destructor Destroy; override;
procedure GetValue(const Name: String; var Value: Variant); virtual;
procedure SetValue(const Name: String; Value: Variant); virtual;
procedure DoFunction(const name: String; p1, p2, p3: Variant;
var val: Variant); virtual;
procedure PrepareScript(MemoFrom, MemoTo, MemoErr: TStrings); virtual;
procedure DoScript(Memo: TStrings); virtual;
procedure SplitExpressions(Memo, MatchFuncs, SplitTo: TStrings;
Variables: TfrVariables);
end;
implementation
type
TCharArray = Array[0..31999] of Char;
PCharArray = ^TCharArray;
lrec = record
name: String[16];
n: Integer;
end;
const
ttIf = #1;
ttGoto = #2;
ttProc = #3;
var
labels: Array[0..100] of lrec;
labc: Integer;
function Remain(const S: String; From: Integer): String;
begin
Result := Copy(s, From, MaxInt);
end;
function GetIdentify(const s: String; var i: Integer): String;
var
k: Integer;
begin
while (i <= Length(s)) and (s[i] <= ' ') do
Inc(i);
k := i;
while (i <= Length(s)) and (s[i] > ' ') do
Inc(i);
Result := Copy(s, k, i - k);
end;
{ TfrInterpretator }
constructor TfrInterpretator.Create;
begin
inherited Create;
FParser := TfrParser.Create;
FParser.OnGetValue := GetValue;
FParser.OnFunction := DoFunction;
end;
destructor TfrInterpretator.Destroy;
begin
FParser.Free;
inherited Destroy;
end;
procedure TfrInterpretator.PrepareScript(MemoFrom, MemoTo, MemoErr: TStrings);
var
i, j, cur, lastp: Integer;
s, bs: String;
len: Integer;
buf: PCharArray;
Error: Boolean;
CutList: TStringList;
procedure DoCommand; forward;
procedure DoBegin; forward;
procedure DoIf; forward;
procedure DoRepeat; forward;
procedure DoWhile; forward;
procedure DoGoto; forward;
procedure DoEqual; forward;
procedure DoExpression; forward;
procedure DoSExpression; forward;
procedure DoTerm; forward;
procedure DoFactor; forward;
procedure DoVariable; forward;
procedure DoConst; forward;
procedure DoLabel; forward;
procedure DoFunc; forward;
procedure DoFuncId; forward;
function last: Integer;
begin
Result := MemoTo.Count;
end;
function CopyArr(cur, n: Integer): String;
begin
SetLength(Result, n);
Move(buf^[cur], Result[1], n);
end;
procedure AddLabel(s: String; n: Integer);
var
i: Integer;
f: Boolean;
begin
f := True;
for i := 0 to labc - 1 do
if labels[i].name = s then f := False;
if f then
begin
labels[labc].name := s;
labels[labc].n := n;
Inc(labc);
end;
end;
procedure SkipSpace;
begin
while (buf^[cur] <= ' ') and (cur < len) do Inc(cur);
end;
function GetToken: String;
var
n, j: Integer;
label 1;
begin
1: SkipSpace;
j := cur;
while (buf^[cur] > ' ') and (cur < len) do
begin
if (buf^[cur] = '{') and (buf^[j] <> #$27) then
begin
n := cur;
while (buf^[cur] <> '}') and (cur < len) do
Inc(cur);
CutList.Add(IntToStr(n) + ' ' + IntToStr(cur - n + 1));
Move(buf^[cur + 1], buf^[n], len - cur);
Dec(len, cur - n + 1);
cur := n;
goto 1;
end
else if (buf^[cur] = '/') and (buf^[cur + 1] = '/') and (buf^[j] <> #$27) then
begin
n := cur;
while (buf^[cur] <> #13) and (cur < len) do
Inc(cur);
CutList.Add(IntToStr(n) + ' ' + IntToStr(cur - n + 1));
Move(buf^[cur + 1], buf^[n], len - cur);
Dec(len, cur - n + 1);
cur := n;
goto 1;
end;
Inc(cur);
end;
Result := AnsiUpperCase(CopyArr(j, cur - j));
if Result = '' then
Result := ' ';
end;
procedure AddError(s: String);
var
i, j, c: Integer;
s1: String;
begin
Error := True;
cur := lastp;
SkipSpace;
for i := 0 to CutList.Count - 1 do
begin
s1 := CutList[i];
j := StrToInt(Copy(s1, 1, Pos(' ', s1) - 1));
c := StrToInt(Copy(s1, Pos(' ', s1) + 1, 255));
if lastp >= j then
Inc(cur, c);
end;
Inc(cur);
i := 0;
c := 0;
j := 0;
while i < MemoFrom.Count do
begin
s1 := MemoFrom[i];
if c + Length(s1) + 1 < cur then
c := c + Length(s1) + 1 else
begin
j := cur - c;
break;
end;
Inc(i);
end;
MemoErr.Add('Line ' + IntToStr(i + 1) + '/' + IntToStr(j) + ': ' + s);
cur := lastp;
end;
procedure ProcessBrackets(var i: Integer);
var
c: Integer;
fl1, fl2: Boolean;
begin
fl1 := True; fl2 := True; c := 0;
Dec(i);
repeat
Inc(i);
if fl1 and fl2 then
if buf^[i] = '[' then
Inc(c) else
if buf^[i] = ']' then Dec(c);
if fl1 then
if buf^[i] = '"' then fl2 := not fl2;
if fl2 then
if buf^[i] = '''' then fl1 := not fl1;
until (c = 0) or (i >= len);
end;
{----------------------------------------------}
procedure DoDigit;
begin
while (buf^[cur] <= ' ') and (cur < len) do Inc(cur);
if buf^[cur] in ['0'..'9'] then
while (buf^[cur] in ['0'..'9']) and (cur < len) do Inc(cur)
else Error := True;
end;
procedure DoBegin;
label 1;
begin
1:DoCommand;
if Error then Exit;
lastp := cur;
bs := GetToken;
if (bs = '') or (bs[1] = ';') then
begin
cur := cur - Length(bs) + 1;
goto 1;
end
else if (bs = 'END') or (bs = 'END;') then cur := cur - Length(bs) + 3
else AddError('Need ";" or "end" here');
end;
procedure DoIf;
var
nsm, nl, nl1: Integer;
begin
nsm := cur;
DoExpression;
if Error then Exit;
bs := ttIf + ' ' + CopyArr(nsm, cur - nsm);
nl := last;
MemoTo.Add(bs);
lastp := cur;
if GetToken = 'THEN' then
begin
DoCommand;
if Error then Exit;
nsm := cur;
if GetToken = 'ELSE' then
begin
nl1 := last;
MemoTo.Add(ttGoto + ' ');
bs := MemoTo[nl]; bs[2] := Chr(last); bs[3] := Chr(last div 256); MemoTo[nl] := bs;
DoCommand;
bs := MemoTo[nl1]; bs[2] := Chr(last); bs[3] := Chr(last div 256); MemoTo[nl1] := bs;
end
else
begin
bs := MemoTo[nl]; bs[2] := Chr(last); bs[3] := Chr(last div 256); MemoTo[nl] := bs;
cur := nsm;
end;
end
else AddError('Need "then" here');
end;
procedure DoRepeat;
label 1;
var
nl, nsm: Integer;
begin
nl := last;
1:DoCommand;
if Error then Exit;
lastp := cur;
bs := GetToken;
if bs = 'UNTIL' then
begin
nsm := cur;
DoExpression;
MemoTo.Add(ttIf + Chr(nl) + Chr(nl div 256) + CopyArr(nsm, cur - nsm));
end
else if bs[1] = ';' then
begin
cur := cur - Length(bs) + 1;
goto 1;
end
else AddError('Need ";" or "until" here');
end;
procedure DoWhile;
var
nl, nsm: Integer;
begin
nl := last;
nsm := cur;
DoExpression;
if Error then Exit;
MemoTo.Add(ttIf + ' ' + CopyArr(nsm, cur - nsm));
lastp := cur;
if GetToken = 'DO' then
begin
DoCommand;
MemoTo.Add(ttGoto + Chr(nl) + Chr(nl div 256));
bs := MemoTo[nl]; bs[2] := Chr(last); bs[3] := Chr(last div 256); MemoTo[nl] := bs;
end
else AddError('Need "do" here');
end;
procedure DoFor;
var
nsm, nl: Integer;
loopvar: String;
begin
nsm := cur;
DoEqual;
if Error then Exit;
bs := Trim(CopyArr(nsm, cur - nsm));
loopvar := Copy(bs, 1, Pos(':=', bs) - 1);
lastp := cur;
if GetToken = 'TO' then
begin
nsm := cur;
DoExpression;
if Error then Exit;
nl := last;
MemoTo.Add(ttIf + ' ' + loopvar + '<=' + CopyArr(nsm, cur - nsm));
lastp := cur;
if GetToken = 'DO' then
begin
DoCommand;
if Error then Exit;
MemoTo.Add(loopvar + ' ' + loopvar + '+1');
MemoTo.Add(ttGoto + Chr(nl) + Chr(nl div 256));
bs := MemoTo[nl]; bs[2] := Chr(last); bs[3] := Chr(last div 256); MemoTo[nl] := bs;
end
else AddError('Need "do" here');
end
else AddError('Need "to" here');
end;
procedure DoGoto;
var
nsm: Integer;
begin
SkipSpace;
nsm := cur;
lastp := cur;
DoDigit;
if Error then AddError('"goto" label must be a number');
MemoTo.Add(ttGoto + Trim(CopyArr(nsm, cur - nsm)));
end;
procedure DoEqual;
var
s: String;
n, nsm: Integer;
begin
nsm := cur;
DoVariable;
s := Trim(CopyArr(nsm, cur - nsm)) + ' ';
lastp := cur;
bs := GetToken;
if (bs = ';') or (bs = '') or (bs = #0) or (bs = 'END') or (bs = 'ELSE') then
begin
s := Trim(CopyArr(nsm, lastp - nsm));
MemoTo.Add(ttProc + s + '(0)');
cur := lastp;
end
else if Pos(':=', bs) = 1 then
begin
cur := cur - Length(bs) + 2;
nsm := cur;
DoExpression;
n := Pos('[', s);
if n <> 0 then
begin
s := ttProc + 'SETARRAY(' + Copy(s, 1, n - 1) + ', ' +
Copy(s, n + 1, Length(s) - n - 2) + ', ' + CopyArr(nsm, cur - nsm) + ')';
end
else
s := s + CopyArr(nsm, cur - nsm);
MemoTo.Add(s);
end
else
AddError('Need ":=" here');
end;
{-------------------------------------}
procedure DoExpression;
var
nsm: Integer;
begin
DoSExpression;
nsm := cur;
bs := GetToken;
if (Pos('>=', bs) = 1) or (Pos('<=', bs) = 1) or (Pos('<>', bs) = 1) then
begin
cur := cur - Length(bs) + 2;
DoSExpression;
end
else if (bs[1] = '>') or (bs[1] = '<') or (bs[1] = '=') then
begin
cur := cur - Length(bs) + 1;
DoSExpression;
end
else cur := nsm;
end;
procedure DoSExpression;
var
nsm: Integer;
begin
DoTerm;
nsm := cur;
bs := GetToken;
if (bs[1] = '+') or (bs[1] = '-') then
begin
cur := cur - Length(bs) + 1;
DoSExpression;
end
else if Pos('OR', bs) = 1 then
begin
cur := cur - Length(bs) + 2;
DoSExpression;
end
else cur := nsm;
end;
procedure DoTerm;
var
nsm: Integer;
begin
DoFactor;
nsm := cur;
bs := GetToken;
if (bs[1] = '*') or (bs[1] = '/') then
begin
cur := cur - Length(bs) + 1;
DoTerm;
end
else if (Pos('AND', bs) = 1) or (Pos('MOD', bs) = 1) then
begin
cur := cur - Length(bs) + 3;
DoTerm;
end
else cur := nsm;
end;
procedure DoFactor;
var
nsm: Integer;
begin
nsm := cur;
bs := GetToken;
if bs[1] = '(' then
begin
cur := cur - Length(bs) + 1;
DoExpression;
SkipSpace;
lastp := cur;
if buf^[cur] = ')' then Inc(cur)
else AddError('Need ")" here');
end
else if bs[1] = '[' then
begin
cur := cur - Length(bs);
ProcessBrackets(cur);
SkipSpace;
lastp := cur;
if buf^[cur] = ']' then Inc(cur)
else AddError('Need "]" here');
end
else if (bs[1] = '+') or (bs[1] = '-') then
begin
cur := cur - Length(bs) + 1;
DoExpression;
end
else if bs = 'NOT' then
begin
cur := cur - Length(bs) + 3;
DoExpression;
end
else
begin
cur := nsm;
DoVariable;
if Error then
begin
Error := False;
cur := nsm;
DoConst;
if Error then
begin
Error := False;
cur := nsm;
DoFunc;
end;
end;
end;
end;
procedure DoVariable;
begin
SkipSpace;
if (buf^[cur] in ['a'..'z', 'A'..'Z']) then
begin
Inc(cur);
while buf^[cur] in ['0'..'9', '_', '.', 'A'..'Z', 'a'..'z'] do Inc(cur);
if buf^[cur] = '(' then
Error := True
else if buf^[cur] = '[' then
begin
Inc(cur);
DoExpression;
if buf^[cur] <> ']' then
Error := True else
Inc(cur);
end;
end
else Error := True;
end;
procedure DoConst;
label 1;
begin
SkipSpace;
if buf^[cur] = #$27 then
begin
1: Inc(cur);
while (buf^[cur] <> #$27) and (cur < len) do Inc(cur);
if (cur < len) and (buf^[cur + 1] = #$27) then
begin
Inc(cur);
goto 1;
end;
if cur = len then Error := True
else Inc(cur);
end
else
begin
DoDigit;
if buf^[cur] = '.' then
begin
Inc(cur);
DoDigit;
end;
end;
end;
procedure DoLabel;
begin
DoDigit;
if buf^[cur] = ':' then Inc(cur)
else Error := True;
end;
procedure DoFunc;
label 1;
begin
DoFuncId;
if buf^[cur] = '(' then
begin
Inc(cur);
SkipSpace;
if buf^[cur] = ')' then
begin
Inc(cur);
exit;
end;
1: DoExpression;
lastp := cur;
SkipSpace;
if buf^[cur] = ',' then
begin
Inc(cur);
goto 1;
end
else if buf^[cur] = ')' then Inc(cur)
else AddError('Need "," or ")" here');
end;
end;
procedure DoFuncId;
begin
SkipSpace;
if buf^[cur] in ['A'..'Z', 'a'..'z'] then
while buf^[cur] in ['0'..'9', '_', '.', 'A'..'Z', 'a'..'z'] do Inc(cur)
else Error := True;
end;
procedure DoCommand;
label 1;
var
nsm: Integer;
begin
1:Error := False;
nsm := cur;
lastp := cur;
bs := GetToken;
if bs = 'BEGIN' then DoBegin
else if bs = 'IF' then DoIf
else if bs = 'REPEAT' then DoRepeat
else if bs = 'WHILE' then DoWhile
else if bs = 'FOR' then DoFor
else if bs = 'GOTO' then DoGoto
else if (bs = 'END') or (bs = 'END;') then
begin
cur := nsm;
Error := False;
end
else if bs = 'UNTIL' then
begin
cur := nsm;
Error := False;
end
else
begin
cur := nsm;
DoLabel;
if Error then
begin
Error := False;
cur := nsm;
DoVariable;
if not Error then
begin
cur := nsm;
DoEqual;
end
else
begin
cur := nsm;
Error := False;
DoExpression;
MemoTo.Add(ttProc + Trim(CopyArr(nsm, cur - nsm)));
end;
end
else
begin
AddLabel(Trim(CopyArr(nsm, cur - nsm)), last);
goto 1;
end;
end;
end;
begin
CutList := TStringList.Create;
Error := False;
GetMem(buf, 32000);
FillChar(buf^, 32000, 0);
len := 0;
for i := 0 to MemoFrom.Count - 1 do
begin
s := MemoFrom[i] + #13;
while Pos(#9, s) <> 0 do
s[Pos(#9, s)] := ' ';
Move(s[1], buf^[len], Length(s));
Inc(len, Length(s));
end;
cur := 0; labc := 0;
MemoTo.Clear;
MemoErr.Clear;
if len > 0 then
DoCommand;
FreeMem(buf, 32000);
CutList.Free;
for i := 0 to MemoTo.Count - 1 do
if MemoTo[i][1] = ttGoto then
begin
s := Remain(MemoTo[i], 2) + ':';
for j := 0 to labc do
if labels[j].name = s then
begin
s := MemoTo[i]; s[2] := Chr(labels[j].n);
s[3] := Chr(labels[j].n div 256); MemoTo[i] := s;
break;
end;
end
else if MemoTo[i][1] = ttIf then
begin
s := FParser.Str2OPZ(Remain(MemoTo[i], 4));
MemoTo[i] := Copy(MemoTo[i], 1, 3) + s;
end
else if MemoTo[i][1] = ttProc then
begin
s := FParser.Str2OPZ(Remain(MemoTo[i], 2));
MemoTo[i] := Copy(MemoTo[i], 1, 1) + s;
end
else
begin
j := 1;
GetIdentify(MemoTo[i], j);
len := j;
s := FParser.Str2OPZ(Remain(MemoTo[i], j));
MemoTo[i] := Copy(MemoTo[i], 1, len) + s;
end;
end;
procedure TfrInterpretator.DoScript(Memo: TStrings);
var
i, j: Integer;
s, s1: String;
begin
i := 0;
while i < Memo.Count do
begin
s := Memo[i];
j := 1;
if s[1] = ttIf then
begin
if FParser.CalcOPZ(Remain(s, 4)) = 0 then
begin
i := Ord(s[2]) + Ord(s[3]) * 256;
continue;
end;
end
else if s[1] = ttGoto then
begin
i := Ord(s[2]) + Ord(s[3]) * 256;
continue;
end
else if s[1] = ttProc then
begin
s1 := Remain(s, 2);
if AnsiUpperCase(s1) = 'EXIT(0)' then
exit;
FParser.CalcOPZ(s1);
end
else
begin
s1 := GetIdentify(s, j);
SetValue(s1, FParser.CalcOPZ(Remain(s, j)));
end;
Inc(i);
end;
end;
procedure TfrInterpretator.SplitExpressions(Memo, MatchFuncs, SplitTo: TStrings;
Variables: TfrVariables);
var
i, j: Integer;
s: String;
FuncSplitter: TfrFunctionSplitter;
begin
FuncSplitter := TfrFunctionSplitter.Create(MatchFuncs, SplitTo, Variables);
i := 0;
while i < Memo.Count do
begin
s := Memo[i];
j := 1;
if s[1] = ttIf then
FuncSplitter.Split(Remain(s, 4))
else if s[1] = ttProc then
FuncSplitter.Split(Remain(s, 2))
else
begin
GetIdentify(s, j);
FuncSplitter.Split(Remain(s, j));
end;
Inc(i);
end;
FuncSplitter.Free;
end;
procedure TfrInterpretator.GetValue(const Name: String; var Value: Variant);
begin
// abstract method
end;
procedure TfrInterpretator.SetValue(const Name: String; Value: Variant);
begin
// abstract method
end;
procedure TfrInterpretator.DoFunction(const Name: String; p1, p2, p3: Variant;
var val: Variant);
begin
// abstract method
end;
end.