diff options
| -rw-r--r-- | docs/users_guide/9.4.1-notes.rst | 11 | ||||
| -rw-r--r-- | docs/users_guide/extending_ghc.rst | 4 |
2 files changed, 13 insertions, 2 deletions
diff --git a/docs/users_guide/9.4.1-notes.rst b/docs/users_guide/9.4.1-notes.rst index 345badec57..42791d7153 100644 --- a/docs/users_guide/9.4.1-notes.rst +++ b/docs/users_guide/9.4.1-notes.rst @@ -72,6 +72,17 @@ Compiler - New :ghc-flag:`-fprof-late` that adds automatic CCS annotations to all top level functions *after* core optimisation have been run. +- Typechecking plugins now support type-family rewriting. The ``TcPlugin`` + datatype now contains an extra field, ``tcPluginRewrite``, which allows + typechecking plugin authors to specify which type families should be + rewritten by the plugin, returning for each type family application a + ``TcPluginRewriteResult``. + In addition, typechecking plugins now have the ability to emit new constraints + at the same time as contradictions. To account for these changes, the + ``TcPluginResult`` datatype has been renamed to ``TcPluginSolveResult``, + which bundles pattern synonyms ``TcPluginOk`` and ``TcPluginContradiction`` + to recover the old interface. + - A new type of plugin: defaulting plugins. These plugins can propose defaults for ambiguous variables that would otherwise cause errors just like the built-in defaulting mechanism. diff --git a/docs/users_guide/extending_ghc.rst b/docs/users_guide/extending_ghc.rst index a265a8323e..c12abc2b4c 100644 --- a/docs/users_guide/extending_ghc.rst +++ b/docs/users_guide/extending_ghc.rst @@ -582,7 +582,7 @@ is defined thus: , tcPluginStop :: s -> TcPluginM () } - type TcPluginSolver = [Ct] -> [Ct] -> [Ct] -> TcPluginM TcPluginResult + type TcPluginSolver = [Ct] -> [Ct] -> [Ct] -> TcPluginM TcPluginSolveResult type TcPluginRewriter = RewriteEnv -> [Ct] -> [Type] -> TcPluginM TcPluginRewriteResult @@ -615,7 +615,7 @@ The basic idea is as follows: - During constraint solving, GHC repeatedly calls ``tcPluginSolve``. This function is provided with the current set of constraints, and - should return a ``TcPluginResult`` that indicates whether a + should return a ``TcPluginSolveResult`` that indicates whether a contradiction was found or progress was made. If the plugin solver makes progress, GHC will re-start the constraint solving pipeline, looping until a fixed point is reached. |