= FAQ
:toc:

Feel free to ask questions and to update answers by editing this page.
Since we try to make as much information as possible available on the
web site and we like to avoid duplication, many of the answers are
simply links to a web page that answers the question.

== How do you pronounce MLton?

<<Pronounce#>>

== How do you cite MLton?

MLton can be cited in an academic paper as:

* MLton n.d.. MLton web site. http://www.mlton.org.
* Stephen Weeks. 2006. Whole-program compilation in MLton. In ML ’06: Proceedings of the 2006 workshop on ML (Portland, Oregon, USA). ACM, 1–1.

== How does MLton's performance compare to other SML compilers and to other languages?

MLton has <<Performance#,excellent performance>>.

== How portable is SML code across SML compilers?

<<StandardMLPortability#>>

== What SML software has been ported to MLton?

<<Libraries#>>

== Does MLton treat monomorphic arrays and vectors specially?

MLton implements monomorphic arrays and vectors (e.g. `BoolArray`,
`Word8Vector`) exactly as instantiations of their polymorphic
counterpart (e.g. `bool array`, `Word8.word vector`).  Thus, there is
no need to use the monomorphic versions except when required to
interface with the <<BasisLibrary#,Basis Library>> or for portability
with other SML implementations.

== Why do I get a Segfault/Bus error in a program that uses `IntInf`/`LargeInt` to calculate numbers with several hundred thousand digits?

<<GMP#>>

== How can I decrease compile-time memory usage?

* Compile with `-verbose 3` to find out if the problem is due to an
SSA optimization pass.  If so, compile with ``-disable-pass __pass__`` to
skip that pass.

* Compile with `@MLton hash-cons 0.5 --`, which will instruct the
runtime to hash cons the heap every other GC.

* Compile with `-polyvariance false`, which is an undocumented option
that causes less code duplication.

Also, please <<Contact#>> us to let us know the problem to help us
better understand MLton's limitations.
