4.4.2 Tool Resources

Each application is represented as a resource client that understands a set of resources. Similar to the resource mechanism employed in the X Window system [Jon89], a resource  is identified by its name, which is unique in the context of a given client, and a resource type. Interdependencies and default values may be specified for all resources of a client. All command-line arguments, required and optional parameters, operation modes, etc. of a tool are accessible as resources. This mechanism ensures that:

1. All tool parameters are explicitly accessed, and
2. Parameters of all tools are accessed in a uniform way.

Resources and resource clients are implemented as object classes in VLISP. Resource types comprise all basic LISP data types  plus additional ones defined by the application.