Activity

From 20 Sep 2018 to 19 Oct 2018

17:19 Bug #1230 (Closed): PrimaryDecomposition with lex ordering: Robbiano reports the following problem:... John Abbott

17:44 Slug #1229 (New): append is slow: Creating a long list by calling @append@ in a loop has run-time quadratic in the final list length.
John Abbott
17:43 Slug #1228: SLUG: filling an array: It does not really matter how we evaluate @LHS := RHS@.
Either side could be expensive to evaluate. Publicly we sho... John Abbott

09:01 Slug #1228: SLUG: filling an array: My proposal in comment 11 is *bad* because, for instance, the computation of an index may be lengthy or may have side... John Abbott

15:03 Slug #1228: SLUG: filling an array: John Abbott wrote:
> I would hope that checking writability is cheap...
We will make some checks.
I want to desi... Anna Maria Bigatti
14:43 Slug #1228: SLUG: filling an array: Here is an alternative to my comment about the semantics of assignment (in comment 7):
# check that @LHS@ is writabl... John Abbott
14:27 Slug #1228: SLUG: filling an array: Yes, we cannot (and probably should not) stop the user from "shooting himself in the foot".
But CoCoA-5 should never... John Abbott

19:43 Slug #1228: SLUG: filling an array: John Abbott wrote:
> I am inclined to think that a user who writes an assignment @LHS := RHS;@ where evaluating @RHS... Anna Maria Bigatti
17:05 Slug #1228: SLUG: filling an array: A potential disadvantage of my proposed semantics is that if the RHS is expensive to evaluate, and the LHS is "obviou... John Abbott
16:51 Slug #1228: SLUG: filling an array: Now I fear there may be some "strange" situations in which nasty things may occur:... John Abbott
15:46 Slug #1228: SLUG: filling an array: I have changed @IndexedAccess::assignmentNeedsOwnership@ so that it gives @false@.
The loop is much faster (0.001s a... John Abbott
15:26 Slug #1228: SLUG: filling an array: In @Interpreter.C@ around line 2065 there is:... John Abbott
15:20 Slug #1228: SLUG: filling an array: I have used profiling to confirm that the list is indeed copied (but why???)
The test code is:... John Abbott

11:16 Slug #1228 (In Progress): SLUG: filling an array: I have just tried the third loop again, but after making the list @sieve@ twice as long, and the loop takes almost tw... John Abbott

10:11 Slug #1228: SLUG: filling an array: I forgot to mention that @N := 9699690@ (product of all primes up to 20).
The third loop is *APPALLINGLY SLOW*, *... John Abbott
10:08 Slug #1228 (In Progress): SLUG: filling an array: It seems that assigning to an array element is surprisingly slow.
Look at the timings in the following session:
<... John Abbott

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CoCoA » CoCoA-5