External Modules

var A: newint, import M
in A:=@B+1

• Modules separately coded and compiled.
• Type-checking of programs with external modules?
• Above program well typed if M contains a declaration for B.

var A: newint,
import external M: { B: intloc, C: comm }
in A:=@B+1

• M is "parameter" to program.
• Additional information gives type of parameter.