Order in symbolic ring: error calling operator

[dkrenn]

sage: R.<r> = ZZ[[]]
sage: o = SR(r.O(2)).operands()[1]; o
Order(r^2)
sage: o.operator()
...
RuntimeError: cannot find SFunction in table

or

x.Order().operator()
...
RuntimeError: cannot find SFunction in table

[cheuberg]

sage: (x+x^2).series(x, 2).operator() is None
True

[rws]

Replying to cheuberg:

sage: (x+x^2).series(x, 2).operator() is None
True

The topmost operator in symbolic series pseries is not a registered function, but it can be seen in the expression tree:

sage: (x+x^2).series(x, 2)._dbgprinttree()
pseries @0x4e2c3b0, hash=0x0, flags=0x3
    1 (numeric) @0x35d70d0, hash=0x0, flags=0x7
    1 (numeric) @0x35d70d0, hash=0x0, flags=0x7
    -----
    function Order @0x4c197f0, serial=12, hash=0x0, flags=0x3, nops=1
        1 (numeric) @0x35d70d0, hash=0x0, flags=0x7
        =====
    2 (numeric) @0x35d7130, hash=0x0, flags=0x7
    -----
    x (symbol) @0x3e5d6d0, serial=5, hash=0xf4f4bfee, flags=0xf, domain=0, iflags=0000000000000000
    0 (numeric) @0x3647180, hash=0x0, flags=0x7

You can see that the function Order is there too. GiNaC::Order is registered in Pynac and imported to Sage (symbolic/ginac.pxd). But it somehow doesn't get into Sage's registry sfunction_serial_dict which is created and used in symbolic/function.pyx.

[behackl]

Replying to rws:

But it somehow doesn't get into Sage's registry sfunction_serial_dict which is created and used in symbolic/function.pyx.

This was because Order was not registered. Should be fixed now.

---

New commits:

​84aa1e2	register Order-function
​318dd7b	add examples and tests
​7a2e948	add seealso-block

[rws]

Passes tests in selected directories. As soon as a patchbot run passes this can be set positive.