Import (Module)

An import represents some resource that a Module needs to be supplied in order to work.

Field Name	Type	Description
module_name	identifier	the name of the module to import from
export_name	identifier	the name of the export in that module
kind	external kind	the kind of import

Instantiating a Module requires the embedding to bind items of the correct type to each import, which is called parametric linking.

Functionally, imports take an externally-defined item and bring it into the corresponding index space for that items type.

Import Types

• Function
  • A function import specifies the signature type for the function.
  • The function supplied for an import must have the specified type.
• Table
  • The table supplied for an import can't have a smaller minimum than requested by the module.
  • If a table import has a specified maximum, the supplied table must have an import and it must be at least as large.
• Memory
  • The memory supplied for an import can't have a smaller minimum than requested by the module.
  • If a memory import has a specified maximum, the supplied memory must have an import and it must be at least as large.
• Global
  • Imported globals must be immutible.

Import Binding

When a Module is instantiated, its imports can be satisfied by either the Host or another Guest Module.