Add Projection with machinery for generic construction

This allows us to make Functors out of ListTable and NonEmptyTable, albeit in the category of projections, but this is still a useful feature.
circuithub · Jul 5, 2021 · 1fb2f67 · 1fb2f67
1 parent f36c733
commit 1fb2f67
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Showing 14 changed files with 655 additions and 19 deletions.
diff --git a/rel8.cabal b/rel8.cabal
@@ -23,6 +23,7 @@ library
     , base ^>= 4.14 || ^>=4.15
     , bytestring
     , case-insensitive
+    , categories
     , comonad
     , contravariant
     , hasql ^>= 1.4.5.1
@@ -55,6 +56,8 @@ library
   other-modules:
     Rel8.Aggregate
 
+    Rel8.Category.Projection
+
     Rel8.Column
     Rel8.Column.ADT
     Rel8.Column.Either
@@ -87,6 +90,7 @@ library
     Rel8.Generic.Construction.ADT
     Rel8.Generic.Construction.Record
     Rel8.Generic.Map
+    Rel8.Generic.Projection
     Rel8.Generic.Record
     Rel8.Generic.Rel8able
     Rel8.Generic.Table

diff --git a/src/Rel8.hs b/src/Rel8.hs
@@ -169,6 +169,10 @@ module Rel8
   , nullaryFunction
   , binaryOperator
 
+    -- ** Projection
+  , Projection
+  , project
+
     -- * Queries
   , Query
   , showQuery
@@ -278,6 +282,7 @@ import Prelude ()
 
 -- rel8
 import Rel8.Aggregate
+import Rel8.Category.Projection
 import Rel8.Column
 import Rel8.Column.ADT
 import Rel8.Column.Either
@@ -298,6 +303,7 @@ import Rel8.Expr.Ord
 import Rel8.Expr.Order
 import Rel8.Expr.Serialize
 import Rel8.Expr.Sequence
+import Rel8.Generic.Projection ()
 import Rel8.Generic.Rel8able ( KRel8able, Rel8able )
 import Rel8.Order
 import Rel8.Query