Under utils/ext-core, update README to mention that ext-core is now on Hackage

[ghc-hetmet.git] / utils / ext-core / README

diff --git a/utils/ext-core/README b/utils/ext-core/README
index 0f6c16b..8191b71 100644 (file)
--- a/utils/ext-core/README
+++ b/utils/ext-core/README
@@ -1,15 +1,83 @@
+This package has moved to Hackage!
+http://hackage.haskell.org/package/extcore-0.2
+
+The version of the stand-alone External Core library in the GHC
+source tree is now out-of-date, and will probably go away eventually.
+Please get the latest version from Hackage.
+
+=====================================================================
+

 A set of example programs for handling external core format.
 
 In particular, typechecker and interpreter give a precise semantics.
 A set of example programs for handling external core format.
 
 In particular, typechecker and interpreter give a precise semantics.

+---------------------
+tjc April/May 2008:
+
+==== Documentation ====
+
+Documentation for the External Core format lives under docs/ext-core in the
+GHC tree. If you are building from HEAD, do not rely on the version of the
+External Core documentation that lives in haskell.org -- it is obsolete!
+
+==== Notes ====
+
+The checker should work on most programs. Bugs (and infelicities) 
+I'm aware of:
+   
+1. There's some weirdness involving funny character literals. This can
+   be fixed by writing a new lexer for chars rather than using Parsec's
+   built-in charLiteral lexer. But I haven't done that.
+
+2. The test driver attempts to find module dependencies automatically,
+   but it's slow. You can turn it off with the "-n" flag to the driver,
+   and specify all dependencies on the command line (you have to include
+   standard library dependencies too.)
+     * It would help to cache dependency info for standard libraries
+       in a file, or something, but that's future work.
+
+3. To avoid implementing some of the I/O primitives and foreign calls,
+   I use a gross hack involving replacing certain standard library
+   modules with simplified versions (found under lib/) that depend on
+   fake "primops" that the Core interpreter implements. This makes it
+   difficult (if not impossible) to load optimized versions of standard
+   libraries right now. Fixing this is future work too.

 
 

-To build, run "make".
+Typechecking all the GHC libraries eats about a gig of heap and takes a
+long time. I blame Parsec. (Someone who was bored, or understood happy
+better than I do, could update the old happy parser, which is still in the
+repo.)
+
+The interpreter is also memory-hungry, but works for small programs
+that only do simple I/O (e.g., putStrLn is okay; not much more than that)
+and don't use Doubles or arrays. For example: exp3_8, gen_regexps, queens,
+primes, rfib, tak, wheel-sieve1, and wheel-sieve2, if modified so as not
+to take input or arguments.
+
+==== Building ====
+
+To run the checker and interpreter, you need to generate External Core
+for all the base, integer and ghc-prim libraries. This can be done by
+adding "-fext-core" to the GhcLibHcOpts in your build.mk file, then
+running "make" under libraries/.

 
 

-To run the checker and interpreter (which currently aren't working anyway),
-you need to generate External Core for all the base, integer and ghc-prim
-libraries. This can be done by adding "-fext-core" to the GhcLibHcOpts in
-your build.mk file, then running "make" under libraries/.

 Then you need to edit Driver.hs and change "baseDir" to point to your GHC
 libraries directory.
 
 Then you need to edit Driver.hs and change "baseDir" to point to your GHC
 libraries directory.
 

-Most recently tested with GHC 6.8.2. I make no claims of portability. --tjc
+Once you've done that, the ext-core library can be built in the usual
+Cabal manner:
+1. runhaskell Setup.lhs configure
+2. runhaskell Setup.lhs build
+3. runhaskell Setup.lhs install
+
+Then, you can build the example Driver program with:
+  ghc -package extcore Driver.hs -o Driver
+
+And finally, you can use the included Makefile to run tests:
+
+  make nofibtest (to run the parser/checker on all nofib programs...
+   for example.)
+  make libtest (to typecheck all the libraries)
+
+Tested with GHC 6.8.2. I make no claims of portability.
+