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| author | Matthias Pall Gissurarson <mpg@mpg.is> | 2020-05-19 22:50:47 +0200 |
|---|---|---|
| committer | Facundo DomÃnguez <facundo.dominguez@tweag.io> | 2020-06-26 17:12:45 +0000 |
| commit | 9ee58f8d900884ac8b721b6b95dbfa6500f39431 (patch) | |
| tree | 2025e2f3ef4a92b252059287ea5d84745eec1118 /libraries/template-haskell/changelog.md | |
| parent | a3d69dc6c2134afe239caf4f881ba5542d2c2be0 (diff) | |
| download | haskell-9ee58f8d900884ac8b721b6b95dbfa6500f39431.tar.gz | |
Implement the proposed -XQualifiedDo extension
Co-authored-by: Facundo DomÃnguez <facundo.dominguez@tweag.io>
QualifiedDo is implemented using the same placeholders for operation names in
the AST that were devised for RebindableSyntax. Whenever the renamer checks
which names to use for do syntax, it first checks if the do block is qualified
(e.g. M.do { stmts }), in which case it searches for qualified names in
the module M.
This allows users to write
{-# LANGUAGE QualifiedDo #-}
import qualified SomeModule as M
f x = M.do -- desugars to:
y <- M.return x -- M.return x M.>>= \y ->
M.return y -- M.return y M.>>
M.return y -- M.return y
See Note [QualifiedDo] and the users' guide for more details.
Issue #18214
Proposal:
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0216-qualified-do.rst
Since we change the constructors `ITdo` and `ITmdo` to carry the new module
name, we need to bump the haddock submodule to account or the new shape of
these constructors.
Diffstat (limited to 'libraries/template-haskell/changelog.md')
| -rw-r--r-- | libraries/template-haskell/changelog.md | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/libraries/template-haskell/changelog.md b/libraries/template-haskell/changelog.md index d3eaa00b4c..0b3aa8d079 100644 --- a/libraries/template-haskell/changelog.md +++ b/libraries/template-haskell/changelog.md @@ -9,7 +9,7 @@ written in terms of `Q` are now disallowed. The types of `unsafeTExpCoerce` and `unTypeQ` are also generalised in terms of `Quote` rather than specific to `Q`. - + * Implement Explicit specificity in type variable binders (GHC Proposal #99). In `Language.Haskell.TH.Syntax`, `TyVarBndr` is now annotated with a `flag`, denoting the additional argument to its constructors `PlainTV` and `KindedTV`. @@ -26,6 +26,9 @@ * Add `MonadFix` instance for `Q` (#12073). + * Add support for QualifiedDo. The data constructors `DoE` and `MDoE` got a new + `Maybe ModName` argument to describe the qualifier of do blocks. + ## 2.16.0.0 *TBA* * Add support for tuple sections. (#15843) The type signatures of `TupE` and |