never executed always true always false

    1 {-# LANGUAGE QuasiQuotes #-}
    2 
    3 module Conjure.Rules.Vertical.Partition.Occurrence where
    4 
    5 import Conjure.Rules.Import
    6 
    7 
    8 rule_Comprehension :: Rule
    9 rule_Comprehension = "partition-comprehension{Occurrence}" `namedRule` theRule where
   10     theRule (Comprehension body gensOrConds) = do
   11         (gocBefore, (pat, expr), gocAfter) <- matchFirst gensOrConds $ \ goc -> case goc of
   12             Generator (GenInExpr pat@Single{} expr) -> return (pat, matchDefs [opToSet, opToMSet] expr)
   13             _ -> na "rule_Comprehension"
   14         let partition_                  =  matchDef opParts expr
   15         TypePartition{}                 <- typeOf partition_
   16         DomainPartition _ _ innerDomain <- domainOf partition_
   17         Partition_Occurrence            <- representationOf partition_
   18         [numPartsVar, whichPart, _partSizesVar, _firstIndexVar] <- downX1 partition_
   19         indexDom                        <- forgetRepr <$> domainOf numPartsVar
   20         let upd val old = lambdaToFunction pat old val
   21         return
   22             ( "Vertical rule for partition-comprehension, Occurrence representation"
   23             , do
   24                 (pPat, p) <- quantifiedVar
   25                 (kPat, k) <- quantifiedVar
   26                 -- the value, a set representing part number p
   27                 -- indicate that there won't be duplicates in this comprehension!
   28                 let val = make opToSetWithFlag True $ Comprehension k
   29                         [ Generator (GenDomainNoRepr kPat innerDomain)
   30                         , Condition [essence| &whichPart[&k] = &p |]
   31                         ]
   32                 return $ Comprehension (upd val body)
   33                         $  gocBefore
   34                         ++ [ Generator (GenDomainNoRepr pPat indexDom)          -- part number p
   35                            , Condition [essence| &p <= &numPartsVar |]
   36                            ]
   37                         ++ transformBi (upd val) gocAfter
   38             )
   39     theRule _ = na "rule_Comprehension"