will@uoregon.uoregon.edu (William Clinger) (05/18/89)
Someone posted an example of unexpected interaction, or lack thereof, between first class environments and incremental DEFINE (using EVAL) in XScheme, and asked: > When I look how environments are implemented I can understand this >behaviour but is this still Scheme? Neither EVAL nor THE-ENVIRONMENT are part of Scheme, so the fact that XScheme happens to define procedures with those names that happen not to work the way someone expects has no bearing on whether it is a real Scheme system. Most people think it is better to think of incremental definitions as part of a programming environment instead of a language, since they are primarily used for debugging. The programming environment obviously differs from one implementation to another, so code that depends on the programming environment is not portable. William Clinger