The MLKit is a compiler toolkit for the Standard ML language, including The MLKit with Regions, which features a native backend for the x64 architecture, based on region inference, and SMLtoJs, which features a JavaScript backend targeting web browsers. The two compilers share the same frontend and compilation management scheme.
The MLKit covers all of Standard ML, as defined in the 1997 edition of The Definition of Standard ML and supports most of the Standard ML Basis Library.
Under macOS, MLKit is available through Homebrew: Just execute brew install mlkit
. Under Linux, you may download the latest binary
tgz-distribution of MLKit from
https://github.com/melsman/mlkit/releases/latest
Once downloaded and unpacked, execute make install
from within the
top-directory of the unpacked distribution. You may install MLKit in a
directory different from /usr/local/mlkit
by instead typing
PREFIX=myinstallpath make install
.
Compiles all of Standard ML. The MLKit compiles all of Standard ML, including Modules, as specified by the Definition of Standard ML. The MLKit also supports most of the Standard ML Basis Library.
Compiles large programs. The MLKit compiles large programs, including itself, around 80.000 lines of Standard ML plus the Standard ML Basis Library. The support for ML Basis Files makes it easy to compile a program with different Standard ML compilers. Currently, both MLton and the MLKit supports the concept of ML Basis Files. The MLKit works well together with smlpkg, a generic package manager for Standard ML libraries and programs.
Documentation is available. Man-pages and general documentation is available from the MLKit home page.
This version of the compiler is based on region inference and has the following features:
An x64 native backend (works with Linux and macOS).
Memory allocation directives (both allocation and deallocation) are inferred by the compiler, which uses a number of program analyses concerning lifetimes and storage layout. The MLKit compiler is unique among ML implementations in this respect.
A comprehensive guide on Programming with Regions in the MLKit is available, which also demonstrates how to create memory profiles of program executions using the supplied region profiler and how to interact with C programs.
Region inference may be augmented with reference-tracing garbage collection to achieve better memory behavior.
This version of the compiler generates efficient JavaScript, primarily for executing Standard ML code in the browser. There is also an online version of SMLtoJs, which makes it possible to write, compile, and execute Standard ML code in a web browser.
The repository also includes the sources for Barry, a Standard ML source-to-source compiler that eliminates modules, using static interpretation, and generates optimised Core-language Standard ML code.
The MLKit compiler is distributed under the GNU Public License,
version 2. See the file MLKit-LICENSE
for details. The runtime system (/src/Runtime/
) and libraries
(basis/
) is distributed under the more liberal MIT License.
To compile, install, and use the MLKit, a Linux box running Ubuntu Linux, Debian, gentoo, or similar is needed. The MLKit also works on macOS and has also earlier been reported to run on the FreeBSD/x64 platform, with a little tweaking.
To compile the MLKit, a Standard ML compiler is needed, which needs to be one of the following:
MLton >= 20051202:
$ mlton
MLton 20051202 (built Sat Dec 03 04:20:11 2005 on pavilion)
If a version prior to 20201023 is used, you may need to adjust the
mlton
-flags setup in the file Makefiledefault
.
A working MLKit compiler >= 4.3.0:
$ mlkit -V
MLKit version 4.3.0, Jan 25, 2006 [X86 Backend]
Moreover, gcc
is needed for compiling the runtime system and related
tools.
After having checked out the sources from Github, execute the command:
$ ./autobuild
Now, cd
to the toplevel directory of the repository and execute the
appropriate set of commands:
Compile with MLton alone (Tested with 3Gb RAM):
$ ./configure
$ make mlkit
Compile with existing MLKit (Tested with 1Gb RAM):
$ ./configure --with-compiler=mlkit
$ make mlkit
If you later want to install the MLKit in your own home directory, you
should also pass the option --prefix=$HOME/mlkit
to ./configure
above.
For binary packages, we use
$ ./configure --sysconfdir=/etc --prefix=/usr
Execute the following command:
$ make mlkit_libs
This step is optional. If you want the resulting executable compiler to be bootstrapped (compiled with itself), execute the command:
$ make bootstrap && make mlkit_libs
Be aware that this step takes some time.
For a system-wide installation of the MLKit, including installation of man-pages and tools, execute the command:
$ sudo make install
For a personal installation, with --prefix=$HOME/mlkit
given to
./configure
, execute the following command:
$ make install
To build a binary package, execute the command
$ make mlkit_x64_tgz
This command leaves a package mlkit-X.Y.Z-x64.tgz
in the dist/
directory. For building a binary package, the installation step above
is not needed and the bootstrapping step is optional. The binary package includes both the MLKit with Regions compiler (i.e., the mlkit
executable) and SMLtoJs (i.e., an executables named smltojs
).
To test the installation, copy the directory /usr/share/mlkit/kitdemo
to
somewhere in your own directory, say $HOME/kitdemo
:
$ cp -a /usr/share/mlkit/kitdemo $HOME/kitdemo
$ cd $HOME/kitdemo
$ mlkit helloworld.sml
The MLKit should produce an executable file run
:
$ ./run
hello world
You can run mlkit
without installing it, but you should then point
the environment variable SML_LIB
at the build directory (which
contains the basis
and the lib
directories) whenever you run
mlkit
. E.g:
$ SML_LIB=$PWD bin/mlkit
See the MLKit home page for information about related papers, etc.
General documentation for the MLKit is located in the directories doc/mlkit
and man/man1
. License information is located in the file
doc/license/MLKit-LICENSE
.
The MLKit has a number of known bugs and limitations. To file a bug-report, create an issue at the Github page.
kit/
README
configure
Makefile.in
src/
basis/
doc/mlkit.pdf
/license/MLKit-LICENSE
man/man1/rp2ps.1
kitdemo/
test/
We assume that MLton >= 20051202 is installed on the system as described above.
After having checked out the sources from Github, execute the command:
$ ./autobuild
To compile the MLKit, execute the following commands:
$ ./configure
$ make mlkit
$ make bootstrap
$ make mlkit_libs
The make bootstrap
command is optional.
To install the MLKit and related tools, execute:
$ sudo make install
See the section "Try It" above to test the installation.
The VCG tool can be used to show region flow graphs.