foreach in switch statement breaks?

[Morloth]

Hey everyone,

I was working to get rid of any HasNext instance in the code and I came across a weird problem. Please consider the following code:

Code: Select all

function PathBuilder::BuildRoadPiece(fromTile, toTile, tileType, length, estimateCost) {

	local buildSucceded = false;
	
	switch (tileType) {
		
		case Tile.ROAD:
			...
			break;
			
		case Tile.TUNNEL:
			...
			break;
			
		case Tile.BRIDGE:
			// Find the cheapest and fastest bridge.
			local bridgeTypes = AIBridgeList_Length(length);
			local bestBridgeType = null;
//			for (local bridge = bridgeTypes.Begin(); bridgeTypes.HasNext(); bridge = bridgeTypes.Next()) {
			foreach (bridge, value in bridgeTypes) {
				if (bestBridgeType == null || (AIBridge.GetPrice(bestBridgeType, length) > AIBridge.GetPrice(bridge, length) && AIBridge.GetMaxSpeed(bridge) >= maxSpeed))
					bestBridgeType = bridge;
			}
		
			// Connect the bridge to the other end. Because the first road tile after the bridge has to
			// be straight, we have to substract a tile in the opposite direction from where the bridge is
			// going. Because we calculated the pathlist in the other direction, the direction is in the
			// opposite direction so we need to add it.
			buildSucceded = AIBridge.BuildBridge(AIVehicle.VT_ROAD, bestBridgeType, fromTile, toTile);
			break;
			
		default:
			assert(false);
	}
	
	// Next check if the build was succesful, and if not store all relevant information.
	if (!buildSucceded) {
		
		// If the error is such we are unable to solve, stop.
		if (!estimateCost && !CheckError([fromTile, toTile, tileType, length]))
			return false;
	}
	
	return true;
}

When I replace the line

Code: Select all

for (local bridge = bridgeTypes.Begin(); bridgeTypes.HasNext(); bridge = bridgeTypes.Next()) {

with

Code: Select all

foreach (bridge, value in bridgeTypes) {

I get the error: Your script made an error the index 'buildSucceded' does not exist on the line:

Code: Select all

	// Next check if the build was succesful, and if not store all relevant information.
	if (!buildSucceded) {

When I change is back everything works normally, does anyone has an idea what is going on here?

Thanks in advance!
Bram

[Morloth]

It seems it's a bug in Squirrel, the following code does work:

Code: Select all

function PathBuilder::BuildRoadPiece(fromTile, toTile, tileType, length, estimateCost) {

   local buildSucceded = false;
   local DUMMY_VARIABLE = 0;
   
   switch (tileType) {
      ...
   }
}

[Dwachs]

Just guessing: maybe there is a semi-colon missing as in foreach(bla; bla) ?

[Zuu]

Does it work if you add an explicit block around your case-code? This is sometimes needed in C++ to get scoping right in switch-case statements.

Code: Select all

foreach(..)
{
  case A:
  {
     local x = 5;
     foreach(key, val in list)
     {
        // ..
     }
  }
}

[Steffl]

This remembers me to a problem which I had with a foreach loop. I had to set the #opcodes setting higher, then my code worked again. I think it is always a good idea to try this, especially when the code fails on an unexpected place.

edit: I read your post carefully now and think that's not the solution to this here. Maybe you should try to use the 'local' keyword in another line.