An invoke-unit/sig or invoke-open-unit/sig expression expands into a invoke-unit or invoke-open-unit expression that first converts a signed unit into a unit. Signatures can be used for importing multiple variables into the invoked unit.
The syntax for invoke-unit/sig is:
(invoke-unit/sig expr invoke-import-element
where each invoke-import-element is one of
)
signature
(id : signature)
A signature elements expands into all of the identifiers
in the signature, using id: prefixes to recursively
flatten sub-signatures. The (id : signature) form
expands into all of the signature's identifiers prefixed with an
additional id: prefix.
The syntax for invoke-open-unit/sig is similar:
(invoke-open-unit/sig expr name-specifier invoke-import-element
)