Adjust examples to work on LuaJIT

Author: alerque

content/examples/snakes.sil

@@ -8,12 +8,12 @@ local snakeimg = SILE.resolveFile(snake)
 snakeGlue.width = SILE.types.length("0pt plus 100000pt")
 function snakeGlue:outputYourself (typesetter, line)
   local scaledWidth = self.width.length
-  if line.ratio and line.ratio < 0 and self.width.shrink > 0 then
+  if line.ratio and line.ratio < 0 and self.width.shrink:tonumber() > 0 then
     scaledWidth = scaledWidth + self.width.shrink * line.ratio
-  elseif line.ratio and line.ratio > 0 and self.width.stretch > 0 then
+  elseif line.ratio and line.ratio > 0 and self.width.stretch:tonumber() > 0 then
     scaledWidth = scaledWidth + self.width.stretch * line.ratio
   end
-  if scaledWidth <= 12 then return end
+  if scaledWidth:tonumber() <= 12 then return end
   SILE.outputter:drawImage(snakeimg, typesetter.frame.state.cursorX, typesetter.frame.state.cursorY - 12, scaledWidth, 12);
   typesetter.frame:advanceWritingDirection(scaledWidth)
 end