From 4384eb741c5718df0c9b01542e39028ea32e1c14 Mon Sep 17 00:00:00 2001 From: Robby Findler Date: Tue, 21 Jul 2009 13:17:13 +0000 Subject: [PATCH] svn: r15518 --- doc/release-notes/redex/HISTORY.txt | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/doc/release-notes/redex/HISTORY.txt b/doc/release-notes/redex/HISTORY.txt index f12b4611f7..cf68843735 100644 --- a/doc/release-notes/redex/HISTORY.txt +++ b/doc/release-notes/redex/HISTORY.txt @@ -1,7 +1,15 @@ v4.2.1 - * improved 'where' conditions in metafunctions and reduction-relations - so that they work with Redex's full pattern language. + * improved 'where' conditions in metafunctions and + reduction-relations so that they work with Redex's full pattern + language. + + This is a backwards incompatible change. In old versions, + variables used in a where clause were independent of the pattern + language. Now, if the variable in a where clause is a literal in + the grammar, the result of the where clause must be that + literal. Similarly, if the variable is a non-terminal, the result + must match that non-terminal. * added 'define-relation'