MLton is run from the command line with a collection of options followed by a file name and a list of files to compile, assemble, and link with.
mlton [option ...] file.{c|mlb|o|sml} [file.{c|o|s|S} ...]
The simplest case is to run mlton foo.sml, where foo.sml contains
a valid SML program, in which case MLton compiles the program to
produce an executable foo. Since MLton does not support separate
compilation, the program must be the entire program you wish to
compile. However, the program may refer to signatures and structures
defined in the Basis Library.
Larger programs, spanning many files, can be compiled with the
ML Basis system. In this case, mlton foo.mlb will
compile the complete SML program described by the basis foo.mlb,
which may specify both SML files and additional bases.