Makes the schema_footer optional and says that it does nothing in Ion Schema 2.0. Essentially, it's a special case of top-level open content now—a special case because it breaks the rules for top-level open content because schema_footer would be a reserved symbol if it wasn't a keyword. This is an entirely backwards compatible change.
Requires the $ion_schema_2_0 version marker to be the first thing in the schema. It was a mistake to allow open content before the version marker because it makes it significantly more complicated to detect the version and read a schema. In practice, no one actually puts open content before the version marker anyway.
Also adds some more examples.
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
Issue #, if available:
Fixes #2
Description of changes:
schema_footeroptional and says that it does nothing in Ion Schema 2.0. Essentially, it's a special case of top-level open content now—a special case because it breaks the rules for top-level open content becauseschema_footerwould be a reserved symbol if it wasn't a keyword. This is an entirely backwards compatible change.$ion_schema_2_0version marker to be the first thing in the schema. It was a mistake to allow open content before the version marker because it makes it significantly more complicated to detect the version and read a schema. In practice, no one actually puts open content before the version marker anyway.By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.