= ShowBasisDirective

A comment of the form
[source,sml]
----
(*#showBasis "<file>"*)
----
is recognized as a directive to save the current basis (i.e., environment) to
`<file>` (in the same format as the `-show-basis <file>` <<CompileTimeOptions#,
compile-time option>>).  The `<file>` is interpreted relative to the source file
in which it appears.  The comment is lexed as a distinct token and is parsed as
a structure-level declaration.  [Note that treating the directive as a top-level
declaration would prohibit using it inside a functor body, which would make the
feature significantly less useful in the context of the MLton compiler sources
(with its nearly fully functorial style).]

This feature is meant to facilitate auto-completion via
https://github.com/MatthewFluet/company-mlton[`company-mlton`] and similar
tools.
