71 lines
1.8 KiB
Python
71 lines
1.8 KiB
Python
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class Tracer():
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def __init__(self):
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raise Exception("Use BaseTracer instead of Tracer")
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def _push(self, op, obj):
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return CompTracer(self, obj, op)
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def __add__(self, other):
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return self._push("+", other)
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def __sub__(self, other):
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return self._push("-", other)
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def __mul__(self, other):
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return self._push("*", other)
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def __truediv__(self, other):
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return self._push("/", other)
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def __pow__(self, other):
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return self._push("**", other)
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def __pos__(self):
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return self
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def __neg__(self):
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return self._push("*", -1)
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def __repr__(self):
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v = self.eval()
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return "<Tracer: "+str(self)+" = "+str(v if v != None else 'Undefined')+">"
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class BaseTracer(Tracer):
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def __init__(self, name, val=None):
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self.name = name
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self.val = val
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def eval(self):
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return self.val
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def __str__(self):
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return self.name
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class CompTracer(Tracer):
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def __init__(self, lParent, rParent, op):
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if not isinstance(lParent, Tracer):
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lParent = BaseTracer(repr(lParent), lParent)
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if not isinstance(rParent, Tracer):
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rParent = BaseTracer(repr(rParent), rParent)
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self.parents = [lParent, rParent]
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self.op = op
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def eval(self):
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l = self.parents[0].eval()
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r = self.parents[1].eval()
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if None in [l,r]:
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return None
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if self.op=="+":
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return l + r
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elif self.op=="-":
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return l - r
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elif self.op=="*":
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return l * r
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elif self.op=="/":
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return l / r
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elif self.op=="**":
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return l ** r
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def __str__(self):
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return "("+str(self.parents[0])+" "+self.op+" "+str(self.parents[1])+")"
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