Alt+Cmd+Store demonstrates how to implement a command-sourced data store that supports branching. This involves a simplified set of git-like functions for working with a collection of command streams that feed into the creation of data models.

Applications

This is a work in progress that has a long way to go. The initial plan involves three applications:

• AltCmd - a command line interface for working with the branch structure (much like the git command line).

• AltExplorer - a sample application used to compose different views of a file system.

• AltCad - a more complex sample application involving the definition of points and lines that are positioned relative to other shapes in a geometric model.

Command Line

The AltCmd application will provide a set of commands for managing branches. The intent will be familiar to anyone who has used git.

• Init - creates a brand new command store

• Clone - creates a copy of a command store

• Branch - creates a new local branch

• Checkout - specifies the branch you want to work with

• Merge - incorporates changes from another local branch

• Fetch - refreshes a store by retrieving recent changes from an upstream store

• Push - sends recent commands to an upstream store

Command Storage

Commands are defined by a set of data entry instructions, serialized as JSON strings using one of 3 storage classes:

• FileStore is used to store command data as files on the local file system. This makes it easy to examine the content of a command store.

• SQLiteStore is used to hold command data as part of a SQLite database on the local file system.

• MemoryStore is a transient store. If an application adds commands to this type of store, they will not persist when the application exits.