This page is part of the web mail archives of SRFI 72 from before July 7th, 2015. The new archives for SRFI 72 contain all messages, not just those from before July 7th, 2015.
Andre, thank you for your work on the hygienic macros SRFI. I'm excited to see the unification which allows the standard list procedures (CAR, CDR, CONS) to work on syntax objects while retaining hygiene. I view this advance in the state of the art as similar to the innovation of unifying control abstractions by providing CALL-WITH-CURRENT-CONTINUATION. I see in the email archives that this feature is controversial. From the discussion I understand the following: PLT Scheme provides extensive functionality in retaining and manipulating syntax location information through the use of opaque syntax objects. The SRFI proposal also provides for associating location information with syntax. However, there is a burden to the implementor. For the location information to be garbage collected, the Scheme implementation would need to provide either weak pointers, the ability to have a pair subtype that contained location information, or generic procedures. What is not clear to me from the discussion is whether: A) The SRFI proposal provides the the ability to carry syntax location information which is just as comprehensive and featureful as PLT Scheme. or, B) While the SRFI proposal provides the ability to carry syntax location information, PLT Scheme is able to provide features through the use of opaque syntax objects that the SRFI proposal can not. Thus my question is: does PLT Scheme have syntax location features that this SRFI proposal is not able to provide? Thank you, Andrew Wilcox