CEP 29 - Packaging of Materials

CEP:

29

Title:

Packaging of Materials

Last-Modified:

2024-03-14

Author:

Katie Mummah <mummah@wisc.edu>

Status:

Draft

Type:

Standards Track

Created:

Paul Wilson

Abstract

For a number of real world applications (e.g. shipping), materials need to be packaged in specific ways. This CEP introduces the concept of a Package that can be applied to a material object to support such use cases.

Characteristics of a Package

Each package will have the following characteristics defined by the user in the input file:

  • name : a human-readable name for the package type

  • fill_min : the minimum quantity of material allowed in that package (default: eps())

  • fill_max : the maximum quantity of material allowed in the package (default: 1e299)

  • strategythe strategy for filling multiple packages, e.g.

    • “first” : fill each package to the maximum before adding another package

    • “equal” : fill all packages with an equal quantity

Each package will also be assigned a unique integer id when it is first created. The default package has id = 1 and represents an unpackaged material. Generally, the user will not need to be aware of the id.

User-Definition of Packages

The input file grammar is extended to support the definition of a list of packages at the top level of the input file, similar to recipes.

Packages are loaded into a map of package names to Package pointers in the Context. The Context has methods to get a particular package based on its name or its id.

Applying Packages

All Resource`s are extended to have an additional integer `package_id_ that refers to the unique integer identifier of the package that currently contains that Resource object. By default, all `Resource`s are unpackaged (id = 1).

When an unpackaged Resource is placed in a package, the packaging strategy is consulted to determine how many packages are required. In some cases of an equal filling strategy, it may be impossible to load a given quantity of material into packages. Otherwise, the original Resource object is divided into multiple objects with the package appropriately defined.

Resource Buffer Behaviors

A new behavior is defined for `ResBuf`s to optionally impose unpackaging of `Resource`s as they are pushed into a resource buffer. Similarly, a new behavior is defined to optionally package materials as they are popped out of a resource buffer.