[Haskell] ANNOUNCE: HaRe, the Haskell Refactorer, version 0.3
H.Li at kent.ac.uk
Fri Nov 19 09:17:19 EST 2004
As part of our project on Refactoring Functional Programs
we are pleased to announce the availability of HaRe 0.3 (also known as
HaRe 19/11/2004), a snapshot of our Haskell Refactorer prototype. Apart
from bug-fixes, there are two major changes since HaRe 0.2.
First, a number of new refactorings have been added to HaRe. They are
of two kinds: module refactorings such as cleaning the imports, moving
a definition from one module to anther module, etc. and data-oriented
refactorings such as from concrete to abstract data type.
Second, we have evolved the architecture of HaRe and derived an API
(documented using Haddock) for program analysis and transformation.
This allows HaRe to serve as a framework for end-users to build their
own refactorings or just program transformations.
You can get HaRe 0.3 and the documentation about how to build your own
Please see the README.txt for build/use instructions and known issues,
and let us know about any problems, bugs, suggestions or additional
platforms you can confirm as working.
The HaRe Team (Huiqing Li, Chris Brown, Claus Reinke, Simon Thompson)
Project email: refactor-fp at kent.ac.uk
Refactoring is the process of changing the structure of programs
without changing their functionality, i.e., refactorings are
meaning-preserving program transformations that implement design
changes. For more details about refactoring, about our project and
for background on HaRe, see our project pages.
HaRe - the Haskell Refactorer:
HaRe is our prototype tool supporting a collection of refactorings
for Haskell 98 (see README.txt for known issues and limitations).
It is implemented as a separate refactoring engine (on top of
Programatica's Haskell frontend and Strafunski's generic traversal
strategy library), with small scripting frontends that call this
engine from either Vim or Emacs. The refactoring engine itself has
been seen to build (with ghc-6.2.1) and run on most flavours of
Windows (cygwin needed to build) and on Suns, so we expect it to
build and work on other unix-like platforms with almost no changes.
In other words, we've tried to make sure that most of you should be
able to build and use HaRe from your favourite OS/editor.
Currently supported refactorings:
removeDef : remove an unused definition
duplicateDef : duplicate a definition under a new name
liftToTopLevel : move a local definition to top level
liftOneLevel : move a local definition one level up
demote : move a definition local to point of use
rename : rename an identifier
introNewDef : turn expression into use of new definition
unfoldDef : replace use of identifier by right-hand side
addOneParameter: add parameter to definition
rmOneParameter : remove unused parameter from definition
generaliseDef : turn expression on rhs of definition into
new parameter of that definition
clean imports : clean the imports to remove unnecessary ones
make import explicit: make the used entities explicit in the identified
add to export : add an item to the export list
remove from export : remove an item from the export list
move def to another module : move a definition from one module to
From concrete to abstract data type: transform a concrete data type to an
abstract one, which is composed from
a sequence of elementary refactorings.
Caveats (see also README.txt):
Please keep in mind that this is a prototype, so we do not recommend
to use it on your productions sources just yet. Just play with it
to get an idea of tool-supported refactoring in Haskell, and send us
your feedback and bug-reports. Our goal is to develop this into a
tool that many of you will find indispensable for Haskell
Functionally, HaRe 0.1 was still roughly the snapshot you'd seen at
the Haskell workshop, packaged up for relative ease of build/use,
but unaware of types and modules, and all refactorings only working
on a single module. It had some annoying issues that plagued some
of our Emacs users, didn't work at all with literate Haskell
files, and had several other minor problems.
HaRe 0.2 did not add refactorings, but all refactorings were
modified to take Haskell's module system into account. This means
that a single refactoring may affect multiple modules in a given
project (e.g., renaming an exported function should trigger
corresponding renamings in all client modules that are part
of the current project), that export/import lists have to be
respected or adapted, and that generally the refactorings
should now work in multi-module settings.
Beyond these major changes, several issues in the Emacs version of
the user interface have been ironed out, there is initial support
for literate Haskell files, and lots of smaller issues have been
dealt with (see README.txt for a few more details).
Interim snapshots have been available since December last year,
and some of you have already played with those. The earliest
snapshots were somewhat buggy, but over the last weeks the software
has stabilised to the extent that we are back to Bug 0 (aka:
insufficient test-coverage!-), and the time has come to distribute
the current snapshot more widely.
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