IndexError when calling from_param on a Parameter with a negative precedence

[maximlt]

Using from_param on a Parameter that has its precedence set to -1 raises an IndexError:

import panel as pn
pn.extension()

class P(param.Parameterized):
    i = param.Integer(default=5, bounds=(1, 10), precedence=-1)
    
    def __init__(self, **params):
        super().__init__(**params)
        widget = pn.widgets.IntSlider.from_param(self.param.i)

p = P()

Traceback:

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
/tmp/ipykernel_40016/3103289026.py in <module>
      6         widget = pn.widgets.IntSlider.from_param(self.param.i)
      7 
----> 8 p = P()

/tmp/ipykernel_40016/3103289026.py in __init__(self, **params)
      4     def __init__(self, **params):
      5         super().__init__(**params)
----> 6         widget = pn.widgets.IntSlider.from_param(self.param.i)
      7 
      8 p = P()

~/miniconda3/envs/cyber-dev37/lib/python3.7/site-packages/panel/widgets/base.py in from_param(cls, parameter, **params)
     71         from ..param import Param
     72         layout = Param(parameter, widgets={parameter.name: dict(type=cls, **params)})
---> 73         return layout[0]
     74 
     75     def _get_model(self, doc, root=None, parent=None, comm=None):

~/miniconda3/envs/cyber-dev37/lib/python3.7/site-packages/panel/pane/base.py in __getitem__(self, index)
    133         Allows pane objects to behave like the underlying layout
    134         """
--> 135         return self.layout[index]
    136 
    137     #----------------------------------------------------------------

~/miniconda3/envs/cyber-dev37/lib/python3.7/site-packages/panel/layout/base.py in __getitem__(self, index)
    160 
    161     def __getitem__(self, index):
--> 162         return self.objects[index]
    163 
    164     def __len__(self):

IndexError: list index out of range

[jbednar]

Makes sense; the Param pane is filtering both by the name specified and by precedence>=0, so the resulting Param pane is empty (no Param matches the given name and has precedence>=0). I think the intention for from_param would be to ignore precedence. e.g. using layout = Param(..., display_threshold=-math.inf).