Andreas Enge <andr...@enge.fr> skribis: > On Mon, Feb 01, 2016 at 08:49:10AM -0500, Thompson, David wrote: >> Here's a potential solution for 'package-with-python2': module >> introspection. AIUI, the issue is that some Python 2 packages need >> extra manual tweaking, but 'package-with-python2' creates package >> variants without these tweaks. Our algorithm could look up >> 'python2-foo' in (gnu packages python) and use that package object, if >> it exists. This would stop the recursive transformation for that >> branch of the dependency graph and allow us to tweak Python 2 variants >> as needed without fear. > > I suggested the same off-line: Rewrite the variable name and use that. > But I was told it could not be done in Guile, so I am happy to stand > corrected.
It’s not that it cannot be done, but rather that this is an R-style hack we’d rather avoid. :-) The reason is that objects live independently of variables, variables can have any names etc. Having computation results depend on how things are named would make things non-deterministic and hard to reason about. Ludo’.
