This page is part of the web mail archives of SRFI 109 from before July 7th, 2015. The new archives for SRFI 109 contain all messages, not just those from before July 7th, 2015.
This is the first of two posts proposing simplifications (reductions in scope) for SRFI 109. The idea is that by removing variable elements, this SRFI (unlike SRFIs 107 and 108) becomes purely lexical in scope: the output of the a SRFI-109-capable reader returns the same thing for a SRFI-109 string literal and a regular string, viz. an immutable Scheme string object. In this first post, I argue against the provision of user-defined entity names. Currently, when an entity reference appears in a SRFI 109 string literal, it is expanded into the identifier $entity:<name>$, where <name> is the entity referred to. Thus &{România} expands to ($string$ "Rom" $entity:acirc$ "nia"). In principle, this permits a user to rebind $entity:acirc$ to something else. However, there seems no reason why this should be allowed; it is only productive of confusion. Such entity references should just expand directly to the character, so that &{România} becomes ($string$ "România"), or just "România". Nor is it likely that anyone will need character entities past the 2237 already provided by the standard W3C list. It is already a requirement that systems not add names that conflict with any of these. True, you cannot write (say) Hindi in the Devanagari script using character entity references only. But if you are going to do that, you will probably want to use a UTF-8 compatible editor with appropriate fonts. I therefore believe that character entities should be expanded directly into characters by the implementation. This eliminates one of the use cases for requiringing SRFI 109 string literals to expand into calls on $string$. I would also strengthen, from a MAY to a SHOULD, the recommendation to implement the whole standard list. -- Man has no body distinct from his soul, John Cowan for that called body is a portion of the soul cowan@xxxxxxxx discerned by the five senses, http://www.ccil.org/~cowan the chief inlets of the soul in this age. --William Blake