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1 parent df577d7 commit c7d14d36d5190c9636f03a12c5e1335afe93c3f2 @bos committed Nov 30, 2011
Showing with 11 additions and 9 deletions.
  1. +11 −9 README.markdown
20 README.markdown
@@ -8,12 +8,13 @@ library.
# Important note for users of GHCi and Template Haskell
To achieve excellent performance for rendering floating point numbers,
-this package uses the
+this package can optionally use the
Unfortunately, due to bugs in GHC, some uses of GHCi and Template
-Haskell can crash if this package is loaded.
+Haskell can crash if the double-conversion package is used. As a
+result, this package's use of double-conversion is disabled by default.
* [5289: Can't use ghci with a library linked against
libstdc++]( (fixed
@@ -23,8 +24,8 @@ Haskell can crash if this package is loaded.
package]( (not yet
fixed at the time of writing)
-If you are affected by these problems, you should expect the 5289
-crash to look like this:
+If you enable use of double-conversion and are affected by these
+problems, you should expect the 5289 crash to look like this:
Loading package double-conversion- ... can't load .so/.DLL for: stdc++
@@ -33,13 +34,14 @@ The 5386 crash causes GHCi to die with a floating point exception
To work around these bugs, this package includes an alternative,
slower, floating point conversion that is written in pure Haskell.
-Because it is 10 times slower than the double-conversion package, it
-is not the default.
+Although it is 10 times slower than the double-conversion package, it
+is the default because it does not crash.
-To use it, reinstall this package by passing the `native` flag to
+If you don't use GHCi or Template Haskell, and you want to force
+the use of double-conversion, you can reinstall this package by
+disabling the `native` flag with `cabal`:
- cabal install -fnative
+ cabal install -f-native --reinstall
Afterwards, you will also need to reinstall any downstream packages
that depend on this one, e.g. the [aeson JSON

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