eqString cs1 cs2 = False
{-# RULES "eqString" (==) = eqString #-}
+-- eqString also has a BuiltInRule in PrelRules.lhs:
+-- eqString (unpackCString# (Lit s1)) (unpackCString# (Lit s2) = s1==s2
\end{code}
id :: a -> a
id x = x
--- lazy function; this is just the same as id, but its unfolding
--- and strictness are over-ridden by the definition in MkId.lhs
--- That way, it does not get inlined, and the strictness analyser
--- sees it as lazy. Then the worker/wrapper phase inlines it.
--- Result: happiness
+-- | The call '(lazy e)' means the same as 'e', but 'lazy' has a
+-- magical strictness property: it is lazy in its first argument,
+-- even though its semantics is strict.
lazy :: a -> a
lazy x = x
+-- Implementation note: its strictness and unfolding are over-ridden
+-- by the definition in MkId.lhs; in both cases to nothing at all.
+-- That way, 'lazy' does not get inlined, and the strictness analyser
+-- sees it as lazy. Then the worker/wrapper phase inlines it.
+-- Result: happiness
+
+
+-- | The call '(inline f)' reduces to 'f', but 'inline' has a BuiltInRule
+-- that tries to inline 'f' (if it has an unfolding) unconditionally
+-- The 'NOINLINE' pragma arranges that inline only gets inlined (and
+-- hence eliminated) late in compilation, after the rule has had
+-- a god chance to fire.
+inline :: a -> a
+{-# NOINLINE[0] inline #-}
+inline x = x
-- Assertion function. This simply ignores its boolean argument.
-- The compiler may rewrite it to @('assertError' line)@.
-- call to 'assert'.
--
-- Assertions can normally be turned on or off with a compiler flag
--- (for GHC, assertions are normally on unless the @-fignore-asserts@
+-- (for GHC, assertions are normally on unless optimisation is turned on
+-- with @-O@ or the @-fignore-asserts@
-- option is given). When assertions are turned off, the first
-- argument to 'assert' is ignored, and the second argument is
-- returned as the result.
-- defined here in Base.lhs
assert :: Bool -> a -> a
assert pred r = r
-
+
+breakpoint :: a -> a
+breakpoint r = r
+
+breakpointCond :: Bool -> a -> a
+breakpointCond _ r = r
+
-- | Constant function.
const :: a -> b -> a
const x _ = x
{-# NOINLINE [0] unpackFoldrCString# #-}
-- Don't inline till right at the end;
-- usually the unpack-list rule turns it into unpackCStringList
+-- It also has a BuiltInRule in PrelRules.lhs:
+-- unpackFoldrCString# "foo" c (unpackFoldrCString# "baz" c n)
+-- = unpackFoldrCString# "foobaz" c n
unpackFoldrCString# addr f z
= unpack 0#
where