Delphi Performance Tip

Here's a small little Delphi performance tip that I'm not sure many people are aware of. Putting the $EXTERNALSYM after the symbol has better compiler performance than placing it before the symbol. The reason for this is pretty simple. When the compiler encounters a $EXTERNALSYM it looks for the symbol. If the symbol isn't found then it must be stored and dealt with later. If the symbol is found it is used immediately.

Here's a small example:

const
  MAPVK_VK_TO_VSC    = 0;
  {$EXTERNALSYM MAPVK_VK_TO_VSC}
  MAPVK_VSC_TO_VK    = 1;
  {$EXTERNALSYM MAPVK_VSC_TO_VK}
  MAPVK_VK_TO_CHAR   = 2;
  {$EXTERNALSYM MAPVK_VK_TO_CHAR}
  MAPVK_VSC_TO_VK_EX = 3;
  {$EXTERNALSYM MAPVK_VSC_TO_VK_EX}
  MAPVK_VK_TO_VSC_EX = 4;
  {$EXTERNALSYM MAPVK_VK_TO_VSC_EX}

Happy Square Root Day!

I hope everyone is having a happy Square Root Day.

I have a photograph of a square root in Costa Rica but my photo library isn't available at the moment.