Unbox around runRW#
Because runRW#
inlines so late, we don't end up unboxing around it. For example, suppose we write
f x = runST $ do
mar <- newArray 100 x
unsafeFreeze mar
This will compile to something like
f x = case runRW# (\s ->
case newArray# 100# x s of { (# s', mar #) ->
case unsafeFreezeArray# mar s' of { (# s'', ar# #) ->
(# s'', Array ar# #) }}) of
(# _, ar #) -> ar
We generally want to pull the constructor application out of the runRW#
argument:
f x = case runRW# (\s ->
case newArray# 100# x s of { (# s', mar #) ->
unsafeFreezeArray# mar s' }) of
(# _, ar# #) -> Array ar#
This exposes the Array
constructor to case-of-case.
Trac metadata
Trac field | Value |
---|---|
Version | 8.4.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | low |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |