Type-safe function apply

[jclark]

Should be possible to apply a function value to a container representing an argument list in a type-safe way. This is probably just a generalization of the semantics of ...x.

This is for when the type of the function is known at compile time. There is also a need for a more dynamic, non type-safe version, for when the type is not known.

This relates to #27.

[jclark]

See also #38

[jclark]

Assuming redesign of named arguments from #27, we can provide this by

• allowing tuple types to have a rest part Allow tuples to have rest type #51
• specifying semantic of ...x to be equivalent to specifying each member of the list

[jclark]

The only part left of this is #51, so we can close this.