Scheme reports lag, though. They usually codify what existing Scheme compiler/interpreters are already doing. I know I've seen plenty of Scheme code in the wild

Scheme reports lag, though. They usually codify what existing Scheme compiler/interpreters are already doing. I know I've seen plenty of Scheme code in the wild using square brackets interchangeably long before R6RS came out. You can even see the rationale behind this in the Scheme FAQ on Scheme Wiki, which seems to not have been updated since R5RS was current [1] [1] http://community.schemewiki.org/?scheme-faq-language#H-yoyi82 http://community.schemewiki.org/?scheme-faq-language#H-yoyi8...