- Made it use primitives instead of foreign functions.
- This fixed an issue where the interpreter loop was running re-entrantly.
- Which in turn fixed a GC bug.
- Report a runtime error if the argument isn't a string.
- Report a runtime error if the source doesn't compile.
This makes it clear which files are part of the VM (i.e. the Wren library)
and which are part of the CLI. Makes a directory for the latter so it has
some room to grow.
This probably totally broke the VS project. If you can fix that, send me
a PR!