54 lines
1.1 KiB
Python
54 lines
1.1 KiB
Python
#! /usr/bin/env python
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# -*- coding: utf-8 -*-
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# vim:fenc=utf-8
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#
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# Copyright © 2017 lafrite <lafrite@Poivre>
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#
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# Distributed under terms of the MIT license.
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"""
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Evaluating a binary tree
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"""
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from .operator import OPERATORS
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class ComputeError(Exception):
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pass
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def compute(node, left_v, right_v):
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"""
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Computing a node
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:example:
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>>> compute("+", 1, 2)
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3
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>>> compute("-", None, 2)
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-2
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>>> compute("-", 1, 2)
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Traceback (most recent call last):
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...
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mapytex.calculus.core.evaluate.ComputeError: left_v need to be None for operator with arity 1
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"""
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op = OPERATORS[node]
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lv = left_v
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rv = right_v
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if op['arity'] == 1:
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if lv is None:
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return op["operate"](rv)()
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else:
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raise ComputeError("left_v need to be None for operator with arity 1")
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else:
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try:
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return op["operate"](lv)(rv)
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except NotImplemented:
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return op["roperate"](rv)(lv)
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# -----------------------------
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# Reglages pour 'vim'
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# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
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# cursor: 16 del
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