Records (#6)

* Add Data instances for simple AST
* ExtXXX records take an extra String for labels if a constructor is a record
* Make the extension constructor a record if all others are
* Clean up warnings in examples
* Generate record patsyns for record constructors
* Add record examples in examples/ & docs

Co-authored-by: Christopher Goes <cwgoes@pluranimity.org>

Author: andy-morris

examples/deriv/Deriv.hs

@@ -9,6 +9,7 @@ extendA "A" [] [t|T|] $ defaultExtA {
 
 extendB "B" [] [t|T|] $ defaultExtB
 
+main :: IO ()
 main = print $
   (A (B "") 5 ["a", "b"]) ==
   (A (B "") 5 ["a", "b", "c"] :: A String)

examples/param/Param.hs

@@ -9,4 +9,5 @@ do an <- newName "a"
      typeTX = [("Extra", a)]
    }
 
+main :: IO ()
 main = pure ()

examples/qualified/Qualified.hs

@@ -4,4 +4,5 @@ QualifiedBase.extendT "T" [] [t|()|] $ QualifiedBase.defaultExtT {
   QualifiedBase.typeTX = [("C", [t|Char|])]
 }
 
+main :: IO ()
 main = pure ()

examples/record/Record.hs

@@ -0,0 +1,17 @@
+import Extensible
+import qualified RecordBase as R
+import qualified RecordBase
+
+
+data WithString
+
+R.extendRec "Rec" [] [t|WithString|] $
+  R.defaultExtRec {
+    R.typeR1 = Ann ("label1", [t|String|]),
+    R.typeR2 = Ann ("label2", [t|String|]),
+    R.typeRecX = [("R3", "contents", [t|Int|])]
+  }
+
+main :: IO ()
+main = print (R1 {beep = True, boop = 4, label1 = "hello"} :: Rec)
+  -- type annotation needed until the pat syns get signatures :/

examples/record/RecordBase.hs

@@ -0,0 +1,11 @@
+module RecordBase where
+
+import Extensible
+
+
+extensible [d|
+    data Rec
+      = R1 { beep :: Bool, boop :: Int }
+      | R2 { inner :: Rec }
+      deriving Show
+  |]

extensible-data.cabal

@@ -44,7 +44,10 @@ common example
   default-extensions:
     TemplateHaskell, TypeFamilies, PatternSynonyms, ConstraintKinds,
     StandaloneDeriving, FlexibleContexts, UndecidableInstances
-  ghc-options: -Wno-unused-top-binds -Wno-missing-pattern-synonym-signatures
+  ghc-options:
+    -Wno-unused-top-binds
+    -Wno-missing-pattern-synonym-signatures
+    -Wno-unused-imports
   if flag(dump-splices)
     ghc-options: -ddump-splices -fforce-recomp
   if !flag(build-examples)
@@ -85,3 +88,9 @@ executable deriv
   hs-source-dirs: examples/deriv
   main-is: Deriv.hs
   other-modules: DerivBase
+
+executable record
+  import: deps, example
+  hs-source-dirs: examples/record
+  main-is: Record.hs
+  other-modules: RecordBase