Make ImplicitParams render correctly (#260)

This introduces a new precedence level for single contexts (because implicit param contexts always need parens around them, but other types of contexts don't necessarily, even when alone)
author: Niklas Haas <git@nand.wakku.to> 2014-02-23 15:21:52 +0100
committer: Niklas Haas <git@nand.wakku.to> 2014-02-23 15:21:52 +0100
commit: 14531f7838c5abd0ba2aaf5217a477194d7b1897 (patch)
tree: 193113d2e0c81bb918b5436f34618b5f4d5c2f77
parent: 1944b94edca881d14e979d564719da6f196f8e63 (diff)
4 files changed, 112 insertions, 8 deletions
diff --git a/html-test/ref/ImplicitParams.html b/html-test/ref/ImplicitParams.html
new file mode 100644
index 00000000..0219b323
--- /dev/null
+++ b/html-test/ref/ImplicitParams.html
@@ -0,0 +1,89 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml"
+><head
+  ><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"
+     /><title
+    >ImplicitParams</title
+    ><link href="ocean.css" rel="stylesheet" type="text/css" title="Ocean"
+     /><script src="haddock-util.js" type="text/javascript"
+    ></script
+    ><script type="text/javascript"
+    >//<![CDATA[
+window.onload = function () {pageLoad();setSynopsis("mini_ImplicitParams.html");};
+//]]>
+</script
+    ></head
+  ><body
+  ><div id="package-header"
+    ><ul class="links" id="page-menu"
+      ><li
+	><a href="index.html"
+	  >Contents</a
+	  ></li
+	><li
+	><a href="doc-index.html"
+	  >Index</a
+	  ></li
+	></ul
+      ><p class="caption empty"
+      >&nbsp;</p
+      ></div
+    ><div id="content"
+    ><div id="module-header"
+      ><table class="info"
+	><tr
+	  ><th
+	    >Safe Haskell</th
+	    ><td
+	    >Safe-Inferred</td
+	    ></tr
+	  ></table
+	><p class="caption"
+	>ImplicitParams</p
+	></div
+      ><div id="interface"
+      ><h1
+	>Documentation</h1
+	><div class="top"
+	><p class="src"
+	  ><span class="keyword"
+	    >data</span
+	    > <a name="t:X" class="def"
+	    >X</a
+	    ></p
+	  ></div
+	><div class="top"
+	><p class="src"
+	  ><a name="v:c" class="def"
+	    >c</a
+	    > :: (?x :: <a href="ImplicitParams.html#t:X"
+	    >X</a
+	    >) =&gt; <a href="ImplicitParams.html#t:X"
+	    >X</a
+	    ></p
+	  ></div
+	><div class="top"
+	><p class="src"
+	  ><a name="v:d" class="def"
+	    >d</a
+	    > :: (?x :: <a href="ImplicitParams.html#t:X"
+	    >X</a
+	    >, ?y :: <a href="ImplicitParams.html#t:X"
+	    >X</a
+	    >) =&gt; (<a href="ImplicitParams.html#t:X"
+	    >X</a
+	    >, <a href="ImplicitParams.html#t:X"
+	    >X</a
+	    >)</p
+	  ></div
+	></div
+      ></div
+    ><div id="footer"
+    ><p
+      >Produced by <a href="http://www.haskell.org/haddock/"
+	>Haddock</a
+	> version 2.14.0</p
+      ></div
+    ></body
+  ></html
+>
diff --git a/html-test/src/ImplicitParams.hs b/html-test/src/ImplicitParams.hs
new file mode 100644
index 00000000..4595b8f7
--- /dev/null
+++ b/html-test/src/ImplicitParams.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE ImplicitParams #-}
+module ImplicitParams where
+
+data X
+
+c :: (?x :: X) => X
+c = ?x
+
+d :: (?x :: X, ?y :: X) => (X, X)
+d = (?x, ?y)
diff --git a/src/Haddock/Backends/Xhtml/Decl.hs b/src/Haddock/Backends/Xhtml/Decl.hs
index 72369069..427d5670 100644
--- a/src/Haddock/Backends/Xhtml/Decl.hs
+++ b/src/Haddock/Backends/Xhtml/Decl.hs
@@ -325,7 +325,7 @@ ppContext cxt unicode qual = ppContextNoLocs (map unLoc cxt) unicode qual
 
 ppHsContext :: [HsType DocName] -> Bool -> Qualification-> Html
 ppHsContext []  _       _     = noHtml
-ppHsContext [p] unicode qual = ppType unicode qual p
+ppHsContext [p] unicode qual = ppCtxType unicode qual p
 ppHsContext cxt unicode qual = parenList (map (ppType unicode qual) cxt)
 
 
@@ -669,14 +669,16 @@ tupleParens _              = parenList
 --------------------------------------------------------------------------------
 
 
-pREC_TOP, pREC_FUN, pREC_OP, pREC_CON :: Int
+pREC_TOP, pREC_CTX, pREC_FUN, pREC_OP, pREC_CON :: Int
 
 pREC_TOP = 0 :: Int   -- type in ParseIface.y in GHC
-pREC_FUN = 1 :: Int   -- btype in ParseIface.y in GHC
+pREC_CTX = 1 :: Int   -- Used for single contexts, eg. ctx => type
+                      -- (as opposed to (ctx1, ctx2) => type)
+pREC_FUN = 2 :: Int   -- btype in ParseIface.y in GHC
                       -- Used for LH arg of (->)
-pREC_OP  = 2 :: Int   -- Used for arg of any infix operator
+pREC_OP  = 3 :: Int   -- Used for arg of any infix operator
                       -- (we don't keep their fixities around)
-pREC_CON = 3 :: Int   -- Used for arg of type applicn:
+pREC_CON = 4 :: Int   -- Used for arg of type applicn:
                       -- always parenthesise unless atomic
 
 maybeParen :: Int           -- Precedence of context
@@ -693,8 +695,10 @@ ppLParendType unicode qual y = ppParendType unicode qual (unLoc y)
 ppLFunLhType  unicode qual y = ppFunLhType unicode qual (unLoc y)
 
 
-ppType, ppParendType, ppFunLhType :: Bool -> Qualification-> HsType DocName -> Html
+ppType, ppCtxType, ppParendType, ppFunLhType :: Bool -> Qualification
+                                             -> HsType DocName -> Html
 ppType       unicode qual ty = ppr_mono_ty pREC_TOP ty unicode qual
+ppCtxType    unicode qual ty = ppr_mono_ty pREC_CTX ty unicode qual
 ppParendType unicode qual ty = ppr_mono_ty pREC_CON ty unicode qual
 ppFunLhType  unicode qual ty = ppr_mono_ty pREC_FUN ty unicode qual
 
@@ -735,7 +739,8 @@ ppr_mono_ty _         (HsKindSig ty kind) u q =
     parens (ppr_mono_lty pREC_TOP ty u q <+> dcolon u <+> ppLKind u q kind)
 ppr_mono_ty _         (HsListTy ty)       u q = brackets (ppr_mono_lty pREC_TOP ty u q)
 ppr_mono_ty _         (HsPArrTy ty)       u q = pabrackets (ppr_mono_lty pREC_TOP ty u q)
-ppr_mono_ty _         (HsIParamTy n ty)   u q = brackets (ppIPName n <+> dcolon u <+> ppr_mono_lty pREC_TOP ty u q)
+ppr_mono_ty ctxt_prec (HsIParamTy n ty)   u q =
+    maybeParen ctxt_prec pREC_CTX $ ppIPName n <+> dcolon u <+> ppr_mono_lty pREC_TOP ty u q
 ppr_mono_ty _         (HsSpliceTy {})     _ _ = error "ppr_mono_ty HsSpliceTy"
 ppr_mono_ty _         (HsQuasiQuoteTy {}) _ _ = error "ppr_mono_ty HsQuasiQuoteTy"
 ppr_mono_ty _         (HsRecTy {})        _ _ = error "ppr_mono_ty HsRecTy"
diff --git a/src/Haddock/Backends/Xhtml/Names.hs b/src/Haddock/Backends/Xhtml/Names.hs
index 24577e2a..33cd4f78 100644
--- a/src/Haddock/Backends/Xhtml/Names.hs
+++ b/src/Haddock/Backends/Xhtml/Names.hs
@@ -46,7 +46,7 @@ ppRdrName :: RdrName -> Html
 ppRdrName = ppOccName . rdrNameOcc
 
 ppIPName :: HsIPName -> Html
-ppIPName = toHtml . unpackFS . hsIPNameFS
+ppIPName = toHtml . ('?':) . unpackFS . hsIPNameFS
 
 
 ppUncheckedLink :: Qualification -> (ModuleName, OccName) -> Html
author	Niklas Haas <git@nand.wakku.to>	2014-02-23 15:21:52 +0100
committer	Niklas Haas <git@nand.wakku.to>	2014-02-23 15:21:52 +0100
commit	14531f7838c5abd0ba2aaf5217a477194d7b1897 (patch)
tree	193113d2e0c81bb918b5436f34618b5f4d5c2f77
parent	1944b94edca881d14e979d564719da6f196f8e63 (diff)