Remove Forbid/PermitFused variants, rename Allocations to Constructions

src/Fusion/Plugin/Types.hs

@@ -21,7 +21,7 @@ module Fusion.Plugin.Types
   -- At most one annotation of each type is allowed per binding (attaching more
   -- than one of the same type is a compile error). Annotations of different
   -- types may be combined -- e.g. a binding may use both an
-  -- 'InspectPatternMatches' and an 'InspectAllocations' annotation to inspect
+  -- 'InspectPatternMatches' and an 'InspectConstructions' annotation to inspect
   -- both positions at once.
 
   -- ** Fusion Annotations
@@ -32,9 +32,12 @@ module Fusion.Plugin.Types
   , NoFuse(..)
 
   -- ** Inspection Annotations
-  -- | Annotations to find fusion violations.
+  -- | Annotations to find fusion violations. Two simple rules hold regardless
+  -- of any other conditions: a type explicitly listed in a @Forbid...@
+  -- annotation is always forbidden; a type explicitly listed in a @Permit...@
+  -- annotation is always allowed.
   , InspectPatternMatches(..)
-  , InspectAllocations(..)
+  , InspectConstructions(..)
   , InspectTypeClasses(..)
   , MaxCoreSize(..)
 
@@ -118,6 +121,12 @@ newtype NoFuseTypes = NoFuseTypes [Name]
 data NoFuse = NoFuse
     deriving (Eq, Data)
 
+-- NOTE: Unboxed types are ignored by these inspection annotations by default.
+-- The @inspect-unboxed@ plugin option turns on their inclusion module-wide,
+-- which is usually sufficient. If in future per-binding control is wanted
+-- instead, the names could take a @#@ suffix, for example
+-- "PermitConstructions#".
+
 -- | A GHC annotation attached to a specific top level binding (via an @ANN@
 -- pragma on the binding, not on a type) that requests a fusion report for the
 -- types /pattern-matched/ (scrutinized, i.e. deconstructed in a @case@) in
@@ -131,49 +140,39 @@ data NoFuse = NoFuse
 --
 -- @
 -- {-\# ANN function1 (ForbidPatternMatches [''Maybe]) #-}
--- {-\# ANN function2 (ForbidFusedPatternMatches [''Maybe] [''Step]) #-}
 -- {-\# ANN function3 (PermitPatternMatches [''Int, ''IO]) #-}
 -- @
 data InspectPatternMatches
     = ForbidPatternMatches [Name]
-    -- ^ Blocklist: report occurrences of exactly the named types found in a
+    -- ^ Blocklist: names explicitly listed here are not allowed to occur in
     -- scrutinizing or deconstructing (pattern-match, i.e. @case@) position in
-    -- the binding, regardless of whether they are annotated with 'Fuse'.
+    -- the binding. When the @forbid-fused@ plugin option is enabled, types
+    -- annotated with 'Fuse' are implictly added to this list.
     | PermitPatternMatches [Name]
-    -- ^ Allowlist: report every type pattern-matched in the binding except the
-    -- named types, which may appear freely.
-    | ForbidFusedPatternMatches [Name] [Name]
-    -- ^ Report pattern-match occurrences of every type annotated with 'Fuse'
-    -- found in the binding -- plus any types named in the first (forbid) list,
-    -- minus any types named in the second (allow) list. A name present in both
-    -- lists is allowed.
+    -- ^ Allowlist: names explicitly mentioned here are always allowed in
+    -- pattern matches in the binding.
     deriving (Eq, Data)
 
 -- | A GHC annotation attached to a specific top level binding (via an @ANN@
 -- pragma on the binding, not on a type) that requests a fusion report for the
--- types /allocated/ (constructed, i.e. built up) in that binding.
+-- types /constructed/ (allocated, i.e. built up) in that binding.
 --
 -- The same name rules as 'InspectPatternMatches' apply: use /type/ names
 -- (double quote, e.g. @''Int@), not data constructor names.
 --
 -- @
--- {-\# ANN function1 (ForbidAllocations [''Maybe]) #-}
--- {-\# ANN function2 (ForbidFusedAllocations [''Maybe] [''Step]) #-}
--- {-\# ANN function3 (PermitAllocations [''Int, ''IO]) #-}
+-- {-\# ANN function1 (ForbidConstructions [''Maybe]) #-}
+-- {-\# ANN function3 (PermitConstructions [''Int, ''IO]) #-}
 -- @
-data InspectAllocations
-    = ForbidAllocations [Name]
-    -- ^ Blocklist: report occurrences of exactly the named types found in a
-    -- constructing (allocating) position in the binding, regardless of whether
-    -- they are annotated with 'Fuse'.
-    | PermitAllocations [Name]
-    -- ^ Allowlist: report every type constructed in the binding except the
-    -- named types, which may appear freely.
-    | ForbidFusedAllocations [Name] [Name]
-    -- ^ Report constructing occurrences of every type annotated with 'Fuse'
-    -- found in the binding -- plus any types named in the first (forbid) list,
-    -- minus any types named in the second (allow) list. A name present in both
-    -- lists is allowed.
+data InspectConstructions
+    = ForbidConstructions [Name]
+    -- ^ Blocklist: names explicitly listed here are not allowed to occur in
+    -- constructing (usually leading to allocations) position in the binding.
+    -- When the @forbid-fused@ plugin option is enabled, types annotated with
+    -- 'Fuse' are implictly added to this list.
+    | PermitConstructions [Name]
+    -- ^ Allowlist: names explicitly mentioned here are always allowed in
+    -- constructing positions in the binding.
     deriving (Eq, Data)
 
 -- | A GHC annotation attached to a specific top level binding (via an @ANN@