56 lines
1.6 KiB
Python
56 lines
1.6 KiB
Python
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#!/usr/bin/env python
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# encoding: utf-8
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from generic import Stack
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def post2in_fix(postfix_tokens):
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""" From the postfix_tokens list compute the corresponding infix_tokens list
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@param postfix_tokens: the postfix list of tokens to transform into infix form. If nothing is set, it takes the value self.postfix_tokens
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@return: the corresponding infix list of tokens if postfix_tokens is set. nothing otherwise but stock it in self.infix_tokens
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>>> post2in_fix([2, 5, '+', 1, '-', 3, 4, '*', '/'])
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['( ', 2, '+', 5, '-', 1, ' )', '/', '( ', 3, '*', 4, ' )']
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"""
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operandeStack = Stack()
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for token in postfix_tokens:
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if self.isOperator(token):
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op2 = operandeStack.pop()
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if self.needPar(op2, token, "after"):
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op2 = ["( ", op2, " )"]
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op1 = operandeStack.pop()
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if self.needPar(op1, token, "before"):
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op1 = ["( ", op1, " )"]
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res = [op1, token, op2]
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operandeStack.push(res)
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else:
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operandeStack.push(token)
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infix_tokens = flatten_list(operandeStack.pop())
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return infix_tokens
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def textRender(postfix_tokens):
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""" A text baser render
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:param postfix_tokens: The postfix list of tokens
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:returns: the text expression
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"""
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infix_tokens = post2in_fix(postfix_tokens)
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return ' '.join(infix_tokens)
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if __name__ == '__main__':
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import doctest
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doctest.testmod()
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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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