utils/uutlEnumHelper.inc

{$IF defined(__ENUM_INTERFACE)}

type __ENUM_HELPER = class
private type
  TValueArray = packed array[0..__ENUM_LENGTH-1] of __ENUM_TYPE;
public
  class function {%H}ToString(const Value: __ENUM_TYPE): String; reintroduce;
  class function TryToEnum(const Str: String; out Value: __ENUM_TYPE): boolean; overload;
  class function ToEnum(const Str: String; const aDefault: __ENUM_TYPE): __ENUM_TYPE; overload;
  class function ToEnum(const Str: String): __ENUM_TYPE; overload;
  class function Values: TValueArray;
strict private
  const TABLE: packed record
    E: TValueArray; // array of values
    N: AnsiString; // comma-separated string of names
  end =

{$ELSEIF defined (__ENUM_IMPLEMENTATION)}

class function __ENUM_HELPER.ToString(const Value: __ENUM_TYPE): String;
var
  i: integer;
begin
  Result:= '';
  if LookupVal(@Value, @TABLE.E, sizeof(__ENUM_TYPE), length(TABLE.E), i) then
    Result:= PickString(TABLE.N, i);
end;

class function __ENUM_HELPER.ToEnum(const Str: String): __ENUM_TYPE;
begin
  if not TryToEnum(Str, Result) then
    raise EConvertErrorAlias.CreateFmt('"%s" is an invalid value',[Str]);
end;

class function __ENUM_HELPER.ToEnum(const Str: String; const aDefault: __ENUM_TYPE): __ENUM_TYPE;
begin
  if not TryToEnum(Str, Result) then
    Result:= aDefault;
end;

class function __ENUM_HELPER.TryToEnum(const Str: String; out Value: __ENUM_TYPE): boolean;
var
  i: integer;
begin
  Result:= LookupString(Str, TABLE.N, i);
  if Result then
    Value:= TABLE.E[i];
end;

class function __ENUM_HELPER.Values: TValueArray;
begin
  Result:= TABLE.E;
end;

{$ENDIF}
{$undef __ENUM_TYPE}
{$undef __ENUM_LENGTH}
{$undef __ENUM_HELPER}