Subversion Repositories oidplus

unit VTSFUNCS;

(************************************************)

(* VTSFUNCS.PAS                                 *)

(* Author:   Daniel Marschall                   *)

(* Revision: 2022-10-11                         *)

(* License:  Apache 2.0                         *)

(* This file contains:                          *)

(* - Various functions                          *)

(************************************************)

interface

function Max(a, b: integer): integer;

function Min(a, b: integer): integer;

function CompareEqualLengthString(a, b: string): integer;

function CompareNumericString(a, b: string): integer;

procedure Beep;

function Trim(s: string): string;

function TrimLineToWidth(s: string; width: integer): string;

function ZeroPad(i: LongInt; n: integer): string;

function LeftPadStr(s: string; n: integer; ch: char): string;

function RightPadStr(s: string; n: integer; ch: char): string;

function RepeatStr(ch: char; n: integer): string;

function DeleteFile(filename: string): boolean;

function FileExists(filename: string): boolean;

function StripLeadingZeros(s: string): string;

function IsPositiveIntegerOrZero(s: string): boolean;

function IsBase36String(s: string): boolean;

function TryStrToInt(s: string; var i: LongInt): boolean;

function StrToInt(s: string): LongInt;

function IntToStr(Value: LongInt): string;

function StringReplace(s, search, replace: string): string;

function LastCharPos(const S: string; const Chr: char): integer;

function LowerCase(s: string): string;

function UpperCase(s: string): string;

function base_convert_bigint(numstring: string; frombase, tobase: integer): string;

implementation

uses

  Crt;

function Max(a, b: integer): integer;

begin

  if a > b then

    Max := a

  else

    Max := b;

end;

function Min(a, b: integer): integer;

begin

  if a < b then

    Min := a

  else

    Min := b;

end;

function CompareEqualLengthString(a, b: string): integer;

var

  ao, bo, i: integer;

begin

  CompareEqualLengthString := 0;

  for i := 1 to Length(a) do

  begin

    ao := Ord(a[i]);

    bo := Ord(b[i]);

    if ao > bo then

    begin

      CompareEqualLengthString := 1;

      break;

    end;

    if ao < bo then

    begin

      CompareEqualLengthString := -1;

      break;

    end;

  end;

end;

function CompareNumericString(a, b: string): integer;

var

  EqualLength: integer;

begin

  EqualLength := Max(Length(a), Length(b));

  a := LeftPadStr(a, EqualLength, '0');

  b := LeftPadStr(b, EqualLength, '0');

  CompareNumericString := CompareEqualLengthString(a, b);

end;

procedure Beep;

begin

  Sound(220); (*220Hz*)

  Delay(200); (*200ms*)

  NoSound;

end;

function Trim(s: string): string;

begin

  while Length(s) > 0 do

  begin

    if s[1] in [#9,#10,#13,' '] then

      Delete(s,1,1)

    else

      break;

  end;

  while Length(s) > 0 do

  begin

    if s[Length(s)] in [#9,#10,#13,' '] then

      Delete(s,Length(s),1)

    else

      break;

  end;

  Trim := s;

end;

function TrimLineToWidth(s: string; width: integer): string;

begin

  if Length(s) > width then

  begin

    s := Copy(s, 1, width-3) + '...';

  end;

  TrimLineToWidth := s;

end;

function ZeroPad(i: LongInt; n: integer): string;

var

  s: string;

begin

  s := IntToStr(i);

  ZeroPad := LeftPadStr(s, n, '0');

end;

function LeftPadStr(s: string; n: integer; ch: char): string;

begin

  while Length(s) < n do

  begin

    s := ch + s;

  end;

  LeftPadStr := s;

end;

function RightPadStr(s: string; n: integer; ch: char): string;

begin

  while Length(s) < n do

  begin

    s := s + ch;

  end;

  RightPadStr := s;

end;

function RepeatStr(ch: char; n: integer): string;

var

  i: integer;

  res: string;

begin

  res := '';

  for i := 1 to n do

  begin

    res := res + ch;

  end;

  RepeatStr := res;

end;

function DeleteFile(filename: string): boolean;

var

  F:  file;

  Ch: Char;

begin

  Assign(F, filename);

  {$I-}

  Reset(F);

  {$I+}

  if IOResult <> 0 then

  begin

    DeleteFile := false; (* cannot find file *)

  end

  else

  begin

    Close(F);

    {$I-}

    Erase(F);

    {$I+}

    DeleteFile := IOResult = 0;

  end;

end;

function FileExists(filename: string): boolean;

var

  F: Text;

begin

  Assign(F, filename);

  {$I-}

  Reset(F);

  {$I+}

  if IoResult = 0 then

  begin

    Close(F);

    FileExists := true;

  end

  else

  begin

    FileExists := false;

  end;

end;

function StripLeadingZeros(s: string): string;

begin

  while (s <> '0') and (Copy(s,1,1) = '0') do

    Delete(s,1,1);

  StripLeadingZeros := s;

end;

function IsPositiveIntegerOrZero(s: string): boolean;

var

  i: integer;

begin

  IsPositiveIntegerOrZero := false;

  if Length(s) = 0 then exit;

  (*if (s[1] = '0') and (s <> '0') then exit;*)

  for i := 1 to Length(s) do

  begin

    if not (s[i] in ['0'..'9']) then exit;

  end;

  IsPositiveIntegerOrZero := true;

end;

function IsBase36String(s: string): boolean;

var

  i: integer;

begin

  IsBase36String := false;

  if Length(s) = 0 then exit;

  (*if (s[1] = '0') and (s <> '0') then exit;*)

  for i := 1 to Length(s) do

  begin

    if not (s[i] in ['0'..'9', 'A'..'Z']) then exit;

  end;

  IsBase36String := true;

end;

function TryStrToInt(s: string; var i: LongInt): boolean;

begin

  if IsPositiveIntegerOrZero(s) then

  begin

    TryStrToInt := true;

    i := StrToInt(s);

  end

  else

  begin

    TryStrToInt := false;

  end;

end;

function StrToInt(s: string): LongInt;

var

  i, Error: Integer;

begin

  Val(s, i, Error);

  StrToInt := i;

end;

function IntToStr(Value: LongInt): string;

var

  s: string;

begin

  Str(Value, s);

  IntToStr := s;

end;

function StringReplace(s, search, replace: string): string;

var

  i: integer;

  output: string;

begin

  if s = '' then

  begin

    StringReplace := '';

    Exit;

  end;

  if search = '' then

  begin

    StringReplace := s;

    exit; (* invalid arg *)

  end;

  output := '';

  while s <> '' do

  begin

    if Copy(s, 1, Length(search)) = search then

    begin

      output := output + replace;

      Delete(s, 1, Length(search));

    end

    else

    begin

      output := output + Copy(s, 1, 1);

      Delete(s, 1, 1);

    end;

  end;

  StringReplace := output;

end;

function LastCharPos(const S: string; const Chr: char): integer;

var

  i: Integer;

begin

  for i := length(S) downto 1 do

  begin

    if S[i] = Chr then

    begin

      LastCharPos := i;

      Exit;

    end;

  end;

  LastCharPos := 0;

  Exit;

end;

function LowerCase(s: string): string;

var

  res: string;

  i: integer;

begin

  res := '';

  for i := 1 to Length(s) do

  begin

    if s[i] in ['A'..'Z'] then

    begin

      res := res + Chr(Ord('a')+(Ord(s[i])-Ord('A')));

    end

    else

    begin

      res := res + s[i];

    end;

  end;

  LowerCase := res;

end;

function UpperCase(s: string): string;

var

  res: string;

  i: integer;

begin

  res := '';

  for i := 1 to Length(s) do

  begin

    if s[i] in ['a'..'z'] then

    begin

      res := res + Chr(Ord('A')+(Ord(s[i])-Ord('a')));

    end

    else

    begin

      res := res + s[i];

    end;

  end;

  UpperCase := res;

end;

function base_convert_bigint(numstring: string; frombase, tobase: integer): string;

var

  i: Integer;

  frombase_str: string;

  tobase_str: string;

  len: Integer;

  number: string;

  divide: Integer;

  newlen: Integer;

  res: string;

begin

  frombase_str := '';

  for i := 0 to frombase-1 do

  begin

    if i < 10 then

      frombase_str := frombase_str + IntToStr(i)

    else

      frombase_str := frombase_str + Chr(Ord('A') + (i-10));

  end;

  tobase_str := '';

  for i := 0 to tobase-1 do

  begin

    if i < 10 then

      tobase_str := tobase_str + IntToStr(i)

    else

      tobase_str := tobase_str + Chr(Ord('A') + (i-10));

  end;

  len := Length(numstring);

  base_convert_bigint := '';

  number := numstring; (* this is a fake "Int8" array (implemented with chars) *)

  for i := 0 to len-1 do

  begin

    number[i+1] := Chr(Pos(UpCase(numstring[i+1]), frombase_str)-1);

  end;

  res := '';

  repeat (* Loop until whole number is converted *)

    divide := 0;

    newlen := 0;

    for i := 0 to len-1 do (* Perform division manually (which is why this works with big numbers) *)

    begin

      divide := divide * frombase + Ord(number[i+1]);

      if (divide >= tobase) then

      begin

        number[newlen+1] := Chr(divide div tobase);

        Inc(newlen);

        divide := divide mod tobase;

      end

      else if newlen > 0 then

      begin

        number[newlen+1] := #0;

        Inc(newlen);

      end;

    end;

    len := newlen;

    res := tobase_str[divide+1] + res; (* Divide is basically "numstring mod tobase" (i.e. the new character) *)

  until newlen = 0;

  base_convert_bigint := res;

end;

end.