ICFP Programming Contest 2014


  1. Question: this spec appears to be unclear about….

    Answer: We may have fixed it already!

    We have been making clarifications and in a few cases fixes to the specification in response to questions. You can see a log of the changes we’ve made in the repository for this site.

  2. Question: What happens when the Lambda-Man moves into an empty square and a fruit appears in that same tick? In the next Lambda-Man move scheduled for 127 ticks ahead, or 137?

    Answer: 127. In this extremely rare scenario, the fruit basically is pushed right into Lambda-Man’s mouth, and doesn’t slow him down. This is because he schedules his next move right after he moves, which is before the fruit appears, so he technically isn’t eating at that stage.

  3. Question: Do ghost programs get executed every tick or just the ticks when the ghost is scheduled to move?

    Answer: Only on the ticks when the ghost is scheduled to move. We have updated that paragraph in the spec to be less confusing.

  4. Question: The JavaScript simulator just stops and I see an error message in the browser debug console. What’s up?

    Answer: You’ve managed to tickle an error case in the simulator and it’s thrown an exception and then stopped. Report it and we’ll try and fix it.

    For example:

     World/Simulator.hs:290:9-36: Irrefutable pattern failed for pattern Data.Maybe.Just n

    This one appeared in the game simulator between 3am and 10am UK time because we accidentally left some debug code in the sim, sorry!

  5. Question: How do I access the world’s iniital state? I tried LD 0 0 in main, but I get an error!

    Answer You’re probably trying to load main in the Lambda-Man simulator. The main function is initialised in the game simulator.

  6. Question: In this full round specification, does Lambda-Man have to complete the level fully to score points? For example, what happens with the score if Lambda-man has been eaten three times by ghosts?

    Answer: No, Lambda-Man can score points whether he wins or loses a game. Only the score matters, not whether Lambda-Man completes the level or not. The spec has been updated to clarify this point.