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Diffstat (limited to 'doc/manual/bugs.xml')
| -rw-r--r-- | doc/manual/bugs.xml | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/doc/manual/bugs.xml b/doc/manual/bugs.xml index 33c6e767baca..548ce1cab830 100644 --- a/doc/manual/bugs.xml +++ b/doc/manual/bugs.xml @@ -15,6 +15,23 @@ </para> </listitem> + <listitem> + <para> + Unify the concepts of successors and substitutes into a general notion + of <emphasis>equivalent expressions</emphasis>. Expressions are + equivalent if they have the same target paths with the same + identifiers. However, even though they are functionally equivalent, + they may differ stronly with respect to their <emphasis>performance + characteristics</emphasis>. For example, realising a slice is more + efficient that realising the derivation from which that slice was + produced. On the other hand, distributing sources may be more + efficient (storage- or bandwidth-wise) than distributing binaries. So + we need to be able to attach weigths or priorities or performance + annotations to expressions; Nix can then choose the most efficient + expression dependent on the context. + </para> + </listitem> + </itemizedlist> </appendix> |