apply-refact
applies refactorings specified by the
refact
package. It is currently
integrated into HLint to enable the automatic application of suggestions.
apply-refact 0.13.x supports GHC 9.2 through 9.6; 0.12.x and 0.11.x support GHC 9.2 and 9.4; 0.10.x supports GHC 9.2; 0.9.x supports GHC 8.6 through 9.0.
Install
cabal install apply-refact
Alternatively, clone the repo and run cabal install
.
You can also install from Nix:
nix-env -iA nixpkgs.haskellPackages.apply-refact
Executable name is refactor
.
Hlint Integration example
hlint src/Main.hs --refactor --refactor-options="--inplace"
Example Usage
# test.hs
foo = (x)
# hlint.refact -- produced by hlint --serialise
[("test.hs:1:7: Warning: Redundant bracket\nFound:\n (x)\nWhy not:\n
x\n",[Replace {rtype = Expr, pos = SrcSpan {startLine = 1, startCol = 7, endLine
= 1, endCol = 10}, subts = [("x",SrcSpan {startLine = 1, startCol = 8, endLine =
1, endCol = 9})], orig = "x"}])]
> refactor test.hs --refact-file hlint.refact
foo = x
One of either the input file or --refact-file
must be specified on the command
line. If an input file is specified but not --refact-file
then refactor
will
accept refactorings from stdin and vice versa.
The -i
option can be specified to perform the refactoring inplace overwriting
the input file. This option is ignored when input is read from stdin.
The -s
option can be specified to perform a stepwise evaluation of the refact
file. The user is prompted whether to perform each hint before it is performed.
The --pos
option is intended to be used by tooling in order to specify which
specific hint should be performed.
Multiple -X
options may be provided to specify additional default language pragmas which might affect parsing, such as -XLambdaCase
or -XRankNTypes
.
Refact Files
Refact files should be the result of show
on a value of type [(String, [Refactoring SrcSpan])]
. The string is a description of the refactoring, one
description can have many associated refactoring steps.
Library Structure
The executable is provide so that libraries can use apply-refact
without depending on the package.
The implementation relies on ghc-exactprint
which depends itself on GHC. A
transitive dependancy that most developers wish to avoid!
Reporting Bugs
If the program produces a syntactically incorrect result then this is a bug.
Please open an issue on the issue tracker with precise instructions about how to
reproduce it.
- The input file
- The refact file
- The command used to invoke
refactor
There are some known problems with CPP processing. If your library contains CPP
directives other than #ifdef
it is quite likely that the result will be
unexpected.
Debugging
There are also two hidden flags which can be useful for debugging.
--debug
Outputs the GHC AST.
--roundtrip
Performs no refactoring operations on the file but is useful to test whether
unexpected formatting is due to ghc-exactprint
or the refactoring.
Contributing
Contributions are welcome. You can run the tests via cabal test
.