#20074: QQbar cleaning 2
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Reporter: vdelecroix | Owner:
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-7.1
Component: number fields | Resolution:
Keywords: | Merged in:
Authors: Vincent Delecroix | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/vdelecroix/20074 | 66b22b5e512916c0d3f6cfb32cfc1603bb6b1980
Dependencies: #19954 | Stopgaps:
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Description changed by vdelecroix:
Old description:
> We further simplify QQbar code by:
> - using python operator to indentify binary operators instead of strings.
> In other words we replace `'+'` by `operator.add`, `'-'` by
> `operator.sub`, etc
> - writing only one function `binop` instead of `addsub` and `muldiv`.
> - removing the method `kind` of descriptors and instead use the class
> themselves for dispatching
> - detect unions earlier in the code to avoid constructing `ANBinaryExpr`
>
> As a consequence, we have exactification detected earlier
> {{{
> sage: sqrt17 = QQbar(17).sqrt()
> sage: sqrt19 = QQbar(19).sqrt()
> sage: (sqrt17 + sqrt19).exactify()
> sage: sqrt17 * sqrt19 + sqrt17 - sqrt19 * sqrt17 - sqrt17
> 0
> }}}
> Instead of `0.?e-17` on the current beta.
>
> follow up: #19955
New description:
We further simplify QQbar code by:
- using python operator to indentify binary operators instead of strings.
In other words we replace `'+'` by `operator.add`, `'-'` by
`operator.sub`, etc
- writing only one function `binop` instead of `addsub` and `muldiv`.
- removing the methods `kind`, `is_exact`, `is_rational`,
`is_field_element` of descriptors and instead use the class themselves
- removing the method `rational_value` and directly access the `_value`
attribute
- detect unions earlier in the code to avoid constructing `ANBinaryExpr`
As a consequence of the last items, we have exactification detected
earlier
{{{
sage: sqrt17 = QQbar(17).sqrt()
sage: sqrt19 = QQbar(19).sqrt()
sage: (sqrt17 + sqrt19).exactify()
sage: sqrt17 * sqrt19 + sqrt17 - sqrt19 * sqrt17 - sqrt17
0
}}}
Instead of `0.?e-17` on the current beta. See also the better output in
doctests from the commit `012ae18`.
follow up: #19955
--
--
Ticket URL: <http://trac.sagemath.org/ticket/20074#comment:5>
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