Edwood Versions Save

With this version, we have working new-type text buffers (file.Buffer) but it is not yet the default. Since the last release, most changes have been internal: preparing for new-type buffers. However, "visible" changes here also include

• more efficient tag updating (only update the tag when necessary)
• bug fixes and tests for cross-window undo / redo actions
• fixed some race conditions

Newer version, different bugs. Improved windows and Plan9 support. Works on MacOS Big Sur.

Most significant features:

• early support for windows via guitdraw
• new JSON based dump format
• numerous bug fixes
• better test coverage

This is the first useful release. Edwood v0.1 should be a drop-in replacement for Plan9Port Acme with some minor (but different) bugs.