[commit: ghc] ghc-8.0: Remove references to -XRelaxedPolyRec (02f0941)
git at git.haskell.org
git at git.haskell.org
Mon Sep 12 12:42:53 UTC 2016
Repository : ssh://git@git.haskell.org/ghc
On branch : ghc-8.0
Link : http://ghc.haskell.org/trac/ghc/changeset/02f09410fa6b015ad84153c0d7680a5f59d81daa/ghc
>---------------------------------------------------------------
commit 02f09410fa6b015ad84153c0d7680a5f59d81daa
Author: Ben Gamari <bgamari.foss at gmail.com>
Date: Mon Sep 5 19:19:23 2016 -0400
Remove references to -XRelaxedPolyRec
Test Plan: Read it
Reviewers: dfeuer, austin
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D2515
GHC Trac Issues: #11691
(cherry picked from commit feaa31fbc41685d69045ac8d34be4e18f4f27ffd)
>---------------------------------------------------------------
02f09410fa6b015ad84153c0d7680a5f59d81daa
docs/users_guide/bugs.rst | 51 +++++++++++++++++++++++++
docs/users_guide/glasgow_exts.rst | 62 -------------------------------
utils/mkUserGuidePart/Options/Language.hs | 8 ----
3 files changed, 51 insertions(+), 70 deletions(-)
diff --git a/docs/users_guide/bugs.rst b/docs/users_guide/bugs.rst
index a1ec885..006d5ce 100644
--- a/docs/users_guide/bugs.rst
+++ b/docs/users_guide/bugs.rst
@@ -126,6 +126,57 @@ been decided to remove them from the next version of the language
standard. This behaviour can be controlled with the ``DatatypeContexts``
extension. See :ref:`datatype-contexts`.
+.. _infelicities-recursive-groups:
+
+Typechecking of recursive binding groups
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The Haskell Report specifies that a group of bindings (at top level, or
+in a ``let`` or ``where``) should be sorted into strongly-connected
+components, and then type-checked in dependency order
+(`Haskell Report, Section
+4.5.1 <http://www.haskell.org/onlinereport/decls.html#sect4.5.1>`__). As
+each group is type-checked, any binders of the group that have an
+explicit type signature are put in the type environment with the
+specified polymorphic type, and all others are monomorphic until the
+group is generalised (`Haskell Report, Section
+4.5.2 <http://www.haskell.org/onlinereport/decls.html#sect4.5.2>`__).
+
+Following a suggestion of Mark Jones, in his paper `Typing Haskell in
+Haskell <http://citeseer.ist.psu.edu/424440.html>`__, GHC implements a
+more general scheme. In GHC *the dependency analysis ignores references to
+variables that have an explicit type signature*. As a result of this refined
+dependency analysis, the dependency groups are smaller, and more bindings will
+typecheck. For example, consider: ::
+
+ f :: Eq a => a -> Bool
+ f x = (x == x) || g True || g "Yes"
+
+ g y = (y <= y) || f True
+
+This is rejected by Haskell 98, but under Jones's scheme the definition
+for ``g`` is typechecked first, separately from that for ``f``, because
+the reference to ``f`` in ``g``\'s right hand side is ignored by the
+dependency analysis. Then ``g``\'s type is generalised, to get ::
+
+ g :: Ord a => a -> Bool
+
+Now, the definition for ``f`` is typechecked, with this type for ``g``
+in the type environment.
+
+The same refined dependency analysis also allows the type signatures of
+mutually-recursive functions to have different contexts, something that is
+illegal in Haskell 98 (Section 4.5.2, last sentence). GHC only insists that the
+type signatures of a *refined* group have identical type signatures; in practice
+this means that only variables bound by the same pattern binding must have the
+same context. For example, this is fine: ::
+
+ f :: Eq a => a -> Bool
+ f x = (x == x) || g True
+
+ g :: Ord a => a -> Bool
+ g y = (y <= y) || f True
+
.. _infelicities-Modules:
Module system and interface files
diff --git a/docs/users_guide/glasgow_exts.rst b/docs/users_guide/glasgow_exts.rst
index 3015cec..d7ba481 100644
--- a/docs/users_guide/glasgow_exts.rst
+++ b/docs/users_guide/glasgow_exts.rst
@@ -8343,7 +8343,6 @@ Lexically scoped type variables
.. ghc-flag:: -XScopedTypeVariables
- :implies: :ghc-flag:`-XRelaxedPolyRec`
:implies: :ghc-flag:`-XExplicitForAll`
Enable lexical scoping of type variables explicitly introduced with
@@ -8367,9 +8366,6 @@ signature for ``ys``. In Haskell 98 it is not possible to declare a type
for ``ys``; a major benefit of scoped type variables is that it becomes
possible to do so.
-Lexically-scoped type variables are enabled by
-:ghc-flag:`-XScopedTypeVariables`. This flag implies :ghc-flag:`-XRelaxedPolyRec`.
-
Overview
--------
@@ -8582,64 +8578,6 @@ the Haskell Report) can be completely switched off by
restriction is switched off by default in GHCi's interactive options
(see :ref:`ghci-interactive-options`).
-.. _typing-binds:
-
-Generalised typing of mutually recursive bindings
--------------------------------------------------
-
-.. ghc-flag:: -XRelaxedPolyRec
-
- Allow the typechecker to ignore references to bindings with
- explicit type signatures.
-
-The Haskell Report specifies that a group of bindings (at top level, or
-in a ``let`` or ``where``) should be sorted into strongly-connected
-components, and then type-checked in dependency order
-(`Haskell Report, Section
-4.5.1 <http://www.haskell.org/onlinereport/decls.html#sect4.5.1>`__). As
-each group is type-checked, any binders of the group that have an
-explicit type signature are put in the type environment with the
-specified polymorphic type, and all others are monomorphic until the
-group is generalised (`Haskell Report, Section
-4.5.2 <http://www.haskell.org/onlinereport/decls.html#sect4.5.2>`__).
-
-Following a suggestion of Mark Jones, in his paper `Typing Haskell in
-Haskell <http://citeseer.ist.psu.edu/424440.html>`__, GHC implements a
-more general scheme. If :ghc-flag:`-XRelaxedPolyRec` is specified: *the
-dependency analysis ignores references to variables that have an
-explicit type signature*. As a result of this refined dependency
-analysis, the dependency groups are smaller, and more bindings will
-typecheck. For example, consider: ::
-
- f :: Eq a => a -> Bool
- f x = (x == x) || g True || g "Yes"
-
- g y = (y <= y) || f True
-
-This is rejected by Haskell 98, but under Jones's scheme the definition
-for ``g`` is typechecked first, separately from that for ``f``, because
-the reference to ``f`` in ``g``\'s right hand side is ignored by the
-dependency analysis. Then ``g``\'s type is generalised, to get ::
-
- g :: Ord a => a -> Bool
-
-Now, the definition for ``f`` is typechecked, with this type for ``g``
-in the type environment.
-
-The same refined dependency analysis also allows the type signatures of
-mutually-recursive functions to have different contexts, something that
-is illegal in Haskell 98 (Section 4.5.2, last sentence). With
-:ghc-flag:`-XRelaxedPolyRec` GHC only insists that the type signatures of a
-*refined* group have identical type signatures; in practice this means
-that only variables bound by the same pattern binding must have the same
-context. For example, this is fine: ::
-
- f :: Eq a => a -> Bool
- f x = (x == x) || g True
-
- g :: Ord a => a -> Bool
- g y = (y <= y) || f True
-
.. _mono-local-binds:
Let-generalisation
diff --git a/utils/mkUserGuidePart/Options/Language.hs b/utils/mkUserGuidePart/Options/Language.hs
index cb45347..7b58290 100644
--- a/utils/mkUserGuidePart/Options/Language.hs
+++ b/utils/mkUserGuidePart/Options/Language.hs
@@ -601,14 +601,6 @@ languageOptions =
, flagReverse = "-XNoRecursiveDo"
, flagSince = "6.8.1"
}
- , flag { flagName = "-XRelaxedPolyRec"
- , flagDescription =
- "*(deprecated)* Relaxed checking for :ref:`mutually-recursive "++
- "polymorphic functions <typing-binds>`."
- , flagType = DynamicFlag
- , flagReverse = "-XNoRelaxedPolyRec"
- , flagSince = "6.8.1"
- }
, flag { flagName = "-XRoleAnnotations"
, flagDescription =
"Enable :ref:`role annotations <role-annotations>`."
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