@jeroenvandijk that grammar doesn't appear to be valid BNF; many of the string tokens are not properly quoted
Also, instaparse has adopted the angle brackets <>
to mean "hiding tags" (not an EBNF standard) but this AWS grammar uses them in all of the rule names, which might result in weird behavior
for example
<condition_block> = "Condition" : { <condition_map> }
should be
condition_block = "Condition" ":" "{" condition_map "}"
my experience with instaparse, and other parsers for that matter, and external grammars, is pretty much no one provides complete grammars that are machine parseable.
it is incredibly frustrating to find out that, for example, the only grammar for the version 3 of the protobuf type description language available is incomplete and only published as fragments in <pre> blocks on the protobuf website