On Mon, Apr 26, 2010 at 1:05 PM, Nathan O'Treally <not.rea...@online.de> wrote: > On 26 Apr., 19:23, Robert Bradshaw <rober...@math.washington.edu> > wrote: >> On Apr 25, 2010, at 9:26 AM, Nathan O'Treally wrote: >> >> > On 25 Apr., 17:11, Gonzalo Tornaria <torna...@math.utexas.edu> wrote: >> >> Also, the "== doesn't fail" part seems to force this, since it would >> >> be even more awkward to hide the coercion failure. >> >> > See my last two posts. In addition, Sage behaves different to Python >> > in many other cases. >> > (I'd say it is *necessary* to break Python's convention here, i.e. >> > *don't* hide it, following the Principle of Least Astonishment -- to >> > mathematicians, not Python programmers -- and staying or getting ;-) >> > mathematically sound.) >> >> Certainly Sage doesn't blindly follow Python conventions for >> everything (otherwise we wouldn't have a preparser) but there should >> always be good reason to do things differently, at least for >> consistencies sake. One reason raising an exception on [in]equality >> testing is that it would break hetrogenious lists and dictionaries. In >> fact, dictionaries could be broken in a nondeterministic manner. > > Ouch! :D > > But one should never use objects of probably incompatible types as > keys within dictionaries, and a query should cast a "critical type" > *prior* invocation (same for testing membership in lists). > I think it *is* already non-deterministic if you put "equal but > incompatible" keys in a dict and query with a value [of a type] that > *is* "equal and compatible" to *both* stored types/values. > > Class inheritence and templates/parametric polymorphism rock... > Perhaps Sage should divorce Python. :-)
Let's switch to C++! Well, perhaps I should first finish my Lisp-rewrite of Sage [1]. [1] http://www.mail-archive.com/sage-devel@googlegroups.com/msg21687.html -- William -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
