#!/usr/bin/env python
##############################################################################
#
# diffpy.srfit by DANSE Diffraction group
# Simon J. L. Billinge
# (c) 2008 The Trustees of Columbia University
# in the City of New York. All rights reserved.
#
# File coded by: Chris Farrow
#
# See AUTHORS.txt for a list of people who contributed.
# See LICENSE_DANSE.txt for license information.
#
##############################################################################
"""Visitor for extracting the Argument entries in a Literal tree.
ArgFinder extracts all Arguments from a literal tree.
"""
__all__ = ["ArgFinder"]
from diffpy.srfit.equation.visitors.visitor import Visitor
[docs]
class ArgFinder(Visitor):
"""ArgFinder extracts Arguments from a Literal tree.
Parameters
----------
getconsts : bool, optional
The flag that is True (default) to also collect constant
Arguments.
Attributes
----------
args : list
The collected Arguments.
getconsts : bool
The flag that is True to also collect constant Arguments.
"""
def __init__(self, getconsts=True):
self.args = []
self.getconsts = getconsts
return
[docs]
def reset(self):
"""Reset the argument set."""
self.args = []
return
[docs]
def on_argument(self, arg):
"""Collect an Argument node.
Parameters
----------
arg : Argument
The Argument to collect.
Returns
-------
list
The Arguments collected so far.
"""
if self.getconsts or not arg.const:
self.args.append(arg)
return self.args
[docs]
def on_operator(self, op):
"""Collect the Arguments of an Operator node.
Parameters
----------
op : Operator
The Operator whose Arguments are collected.
Returns
-------
list
The Arguments collected so far.
"""
for arg in op.args:
arg.identify(self)
return self.args
# End of file