diff options
Diffstat (limited to 'ghc/compiler/utils/FastString.lhs')
| -rw-r--r-- | ghc/compiler/utils/FastString.lhs | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/ghc/compiler/utils/FastString.lhs b/ghc/compiler/utils/FastString.lhs index 86b2a8a444..a774243398 100644 --- a/ghc/compiler/utils/FastString.lhs +++ b/ghc/compiler/utils/FastString.lhs @@ -22,7 +22,7 @@ module FastString mkFastCharString#, -- :: Addr# -> FastString mkFastCharString2, -- :: Addr -> Int -> FastString - mkFastString#, -- :: Addr# -> Int# -> FastString + mkFastString#, -- :: Addr# -> FastString mkFastSubStringBA#, -- :: ByteArray# -> Int# -> Int# -> FastString mkFastSubString#, -- :: Addr# -> Int# -> Int# -> FastString @@ -112,8 +112,22 @@ data FastString [Int] -- character numbers instance Eq FastString where - a == b = case cmpFS a b of { LT -> False; EQ -> True; GT -> False } - a /= b = case cmpFS a b of { LT -> True; EQ -> False; GT -> True } + -- shortcut for real FastStrings + (FastString u1 _ _) == (FastString u2 _ _) = u1 ==# u2 + a == b = +#ifdef DEBUG + trace ("slow FastString comparison: " ++ + unpackFS a ++ "/" ++ unpackFS b) $ +#endif + case cmpFS a b of { LT -> False; EQ -> True; GT -> False } + + (FastString u1 _ _) == (FastString u2 _ _) = u1 /=# u2 + a /= b = +#ifdef DEBUG + trace ("slow FastString comparison: " ++ + unpackFS a ++ "/" ++ unpackFS b) $ +#endif + case cmpFS a b of { LT -> True; EQ -> False; GT -> True } instance Ord FastString where a <= b = case cmpFS a b of { LT -> True; EQ -> True; GT -> False } @@ -193,7 +207,7 @@ consFS c fs = mkFastStringInt (ord c : unpackIntFS fs) uniqueOfFS :: FastString -> Int# uniqueOfFS (FastString u# _ _) = u# -uniqueOfFS (CharStr a# l#) = case mkFastString# a# l# of { FastString u# _ _ -> u#} -- Ugh! +uniqueOfFS (CharStr a# l#) = case mkFastStringLen# a# l# of { FastString u# _ _ -> u#} -- Ugh! {- [A somewhat moby hack]: to avoid entering all sorts of junk into the hash table, all C char strings @@ -244,8 +258,12 @@ updTbl fs_table_var (FastStringTable uid# arr#) i# ls = (# s2#, () #) }) >> writeIORef fs_table_var (FastStringTable (uid# +# 1#) arr#) -mkFastString# :: Addr# -> Int# -> FastString -mkFastString# a# len# = +mkFastString# :: Addr# -> FastString +mkFastString# a# = + case strLength (A# a#) of { (I# len#) -> mkFastStringLen# a# len# } + +mkFastStringLen# :: Addr# -> Int# -> FastString +mkFastStringLen# a# len# = unsafePerformIO ( readIORef string_table >>= \ ft@(FastStringTable uid# tbl#) -> let @@ -409,7 +427,7 @@ mkFastStringInt str = if all good str mkFastSubString :: Addr -> Int -> Int -> FastString mkFastSubString (A# a#) (I# start#) (I# len#) = - mkFastString# (addrOffset# a# start#) len# + mkFastStringLen# (addrOffset# a# start#) len# \end{code} \begin{code} |