Extract common parameters when showing results

Handler/Query.hs

@@ -651,11 +651,14 @@ resultTable (Entity submissionId submission) = do
                                                         id
                                                         (submissionChallenge submission)
 
+  let (commonParams', strippedTableEntries) = extractCommonParams tableEntries
+  let commonParams = map (\(Entity _ p) -> (parameterName p, OneThing $ parameterValue p)) commonParams'
+
   let paramNames =
         nub
         $ map (parameterName . entityVal)
         $ concat
-        $ map tableEntryParams tableEntries
+        $ map tableEntryParams strippedTableEntries
 
   let maximumNumberOfColumns = 10
 

Handler/Tables.hs

@@ -37,6 +37,8 @@ import Data.Proxy as DPR
 import Control.Lens hiding ((.=), (^.))
 import Data.HashMap.Strict.InsOrd (fromList)
 
+import qualified Data.Set as S
+
 data TestReference = TestReference Text Text
                      deriving (Show, Eq, Ord)
 
@@ -77,6 +79,21 @@ data LeaderboardEntry = LeaderboardEntry {
   leaderboardTeam :: Maybe (Entity Team)
 }
 
+-- | Finds parameters shared by all entries (including values) and removes
+-- them from the entries
+extractCommonParams :: [TableEntry] -> ([Entity Parameter], [TableEntry])
+extractCommonParams [] = ([], [])
+extractCommonParams entries@(firstEntry:_) = (commonParams, map removeParams entries)
+  where commonParams = filter (\p -> paramToNameVal p `S.member` commonNameVals) $ tableEntryParams firstEntry
+        commonNameVals =
+          DL.foldl intersection hS tS
+        (hS:tS) = map (S.fromList
+                         . map paramToNameVal
+                         . tableEntryParams) entries
+        paramToNameVal (Entity _ p) = (parameterName p, parameterValue p)
+        removeParams e
+          = e { tableEntryParams = filter (\p -> paramToNameVal p `S.notMember` commonNameVals) $ tableEntryParams e }
+
 data TableEntry = TableEntry {
   tableEntrySubmission :: Entity Submission,
   tableEntryVariant :: Entity Variant,

templates/result-table.hamlet

@@ -2,4 +2,7 @@
   $if null tableEntries
      <p>No results available. The submission is probably broken.
   $else
-     ^{Table.buildBootstrap (variantTable paramNames tests) tableEntries}
+    ^{Table.buildBootstrap (variantTable paramNames tests) strippedTableEntries}
+
+    $if not (null commonParams)
+        ^{Table.buildBootstrap paramsTable $ commonParams}