import math
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from lark import Transformer, v_args
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@v_args(inline=True)
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class ExpressionTransformer(Transformer):
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def add(self, left, right) -> str:
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result = f"{left} + {right}"
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return result
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def sub(self, left, right) -> str:
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result = f"{left} - {right}"
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return result
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def mul(self, left, right) -> str:
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result = f"{left} * {right}"
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return result
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def div(self, left, right) -> str:
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result = f"{left} / {right}"
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return result
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def exponent(self, left, right) -> str:
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result = f"{left} ** {right}"
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return result
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def number(self, n) -> str:
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return f"{n}"
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def neg(self, expr) -> str:
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return f"-{expr}"
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def var(self, id:str) -> str:
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if id == 'x':
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return id
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elif hasattr(math, id):
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return f"math.{id}"
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else:
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raise ValueError(f"{id} must be 'x' one of constants in math module")
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def function(self, name, argv) -> str:
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if hasattr(math, name):
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return f"math.{name}({argv})"
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else:
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raise ValueError(f"'{name}' is not a valid function name in math module")
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def argv(self, *arg) -> str:
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return f"{', '.join(arg)}"
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