- Node position is public. It represents the node's first character
index in the document.
- Tree offset is private. It represents the distance between the tree's
first character index and it's parent's first character index.
- Tree padding is private. It represents the amount of whitespace
(or other separator characters) immediately preceding the tree.
Previously, if an error happened right at the beginning of an error
production, the error node would be immediately shifted onto the stack
without calling the error handling function.
The lexer doesn't know the expected symbols, so it doesn't have enough
information to construct error nodes. Now, when it encounters an invalid
character, it returns NULL and the parser builds a correct error node.
Now, the root node of a document is always a document node.
It will often have only one child node which corresponds to the grammar's
start symbol, but not always. Currently, it may have more than one child
if there are ubiquitous tokens such as comments at the beginning of the
document. In the future, it will also be possible be possible to have multiple
for the document to have multiple children if the document is partially parsed.
There's no need for a `string` function since one already
exists for Nodes.
Now the root node is always stored on the document. This
means callers of `ts_document_root_node` don't need to release
its return value.
Generated parsers no longer export a parser constructor function.
They now export an opaque Language object which can be set on
Documents directly. This way, the logic for constructing parsers
lives entirely in the runtime. The Languages are just structs which
have no load-time dependency on the runtime
