From 41aa8dfb1121f34b8a86fbb8763ff6312e496cda Mon Sep 17 00:00:00 2001 From: lafrite Date: Sun, 9 Nov 2014 11:23:02 +0100 Subject: [PATCH] switch op1 and op2 to respect operand order --- pymath/render.py | 210 ++++++++--------------------------------------- 1 file changed, 34 insertions(+), 176 deletions(-) diff --git a/pymath/render.py b/pymath/render.py index 05fa577..2ad50da 100644 --- a/pymath/render.py +++ b/pymath/render.py @@ -1,41 +1,20 @@ #!/usr/bin/env python # encoding: utf-8 -from .generic import Stack,flatten_list -from .fraction import Fraction -from .operator import Operator +from .generic import Stack,isOperator -__all__ = ['Render'] +__all__ = ['txt', 'tex', 'p2i'] class Render(object): - """A class which aims to create render functions from three dictionnaries: - - op_infix: dict of caracters or two argument functions - - op_postfix: dict of 2 arguments functions - - other: dict of caracters - Those three dictionnaries while define how a postfix expression will be transform into a string. - """ + """ Create functions which know how to render postfix tokens lists """ - PRIORITY = {"^": 4,"*" : 3, "/": 3, ":": 3, "+": 2, "-":2, "(": 1} - - def __init__(self, op_infix = {}, op_postfix = {}, other = {}, join = " ", type_render = {str: str, int: str, Fraction: str}): + def __init__(self, render): """Initiate the render - @param op_infix: the dictionnary of infix operator with how they have to be render - @param op_postfix: the dictionnary of postfix operator with how they have to be render - @param other: other caracters like parenthesis. - @param raw: the caracter for joining the list of tokens (if False then it returns the list of tokens) - @param type_render: how to render number (str or tex for fractions for example) + :param render: function which take an operator and return a function to render the operator with his operands """ + self.render = render - self.op_infix = op_infix - self.op_postfix = op_postfix - self.other = other - # TODO: there may be issues with PRIORITY if a sign does not appear in PRIORITY - - self.join = join - self.type_render = type_render - - self.operators = list(self.op_infix.keys()) + list(self.op_postfix.keys()) + list(self.other.keys()) def __call__(self, postfix_tokens): """Make the object acting like a function @@ -45,162 +24,41 @@ class Render(object): """ operandeStack = Stack() - - for token in postfix_tokens: - if self.isOperator(token): - - op2 = operandeStack.pop() - if self.needPar(op2, token, "after"): - op2 = [self.other["("] , op2 , self.other[")"]] - - op1 = operandeStack.pop() - if self.needPar(op1, token, "before"): - op1 = [self.other["("] , op1 , self.other[")"]] - - if token in self.op_infix: - if type(self.op_infix[token]) == str: - res = flist([op1 , self.op_infix[token] , op2]) - else: - res = flist([self.op_infix[token](op1, op2)]) - - - elif token in self.op_postfix: - res = flist([self.op_postfix[token](op1, op2)]) - - # Trick to remember the main op when the render will be done! - res.mainOp = token - - operandeStack.push(res) - + + if isOperator(token): + if token.arity == 1: + + op1 = operandeStack.pop() + + operandeStack.push(self.render(token)(op1)) + elif token.arity == 2: + op1 = operandeStack.pop() + op2 = operandeStack.pop() + # Switch op1 and op2 to respect order + operandeStack.push(self.render(token)(op2, op1)) else: operandeStack.push(token) - # Manip pour gerer les cas de listes imbriquées dans d'autres listes - infix_tokens = operandeStack.pop() + return operandeStack.pop() - if type(infix_tokens) == list or type(infix_tokens) == flist: - infix_tokens = flatten_list(infix_tokens) - elif self.isNumerande(infix_tokens): - infix_tokens = [infix_tokens] +txt = Render(lambda x:x.__txt__) +tex = Render(lambda x:x.__tex__) +p2i = Render(lambda x:x.__p2i__) - if self.join: - return self.join.join(flatten_list([self.render_from_type(t) for t in infix_tokens])) - else: - return infix_tokens +if __name__ == '__main__': + from .operator import Operator + mul = Operator("*", 2) + add = Operator("+", 2) + sub1 = Operator("-", 1) + div = Operator("/", 1) + exp = [ 2, 3, add, 4, mul] + print(exp) + print("txt(exp) :" + str(txt(exp))) + print("tex(exp) :" + str(tex(exp))) + print("p2i(exp) :" + str(p2i(exp))) + - def render_from_type(self, op): - """ If the op is a numerande, it transforms it with type_render conditions - - :param op: the operator - :returns: the op transformed if it's necessary - - """ - if self.isNumerande(op): - return self.type_render[type(op)](op) - else: - return op - - - # --------------------- - # Tools for placing parenthesis in infix notation - - def needPar(self, operande, operator, posi = "after"): - """Says whether or not the operande needs parenthesis - - :param operande: the operande - :param operator: the operator - :param posi: "after"(default) if the operande will be after the operator, "before" othewise - :returns: bollean - """ - # Si l'operande est negatif - if self.isNumber(operande) \ - and operande < 0 \ - and posi == "after": - return 1 - - # Pas de parenthèses si c'est une lettre ou une fraction - elif (type(operande) == str and operande.isalpha()) \ - or type(operande) == Fraction: - return 0 - - elif not self.isNumber(operande): - # Si c'est une grande expression - stand_alone = self.get_main_op(operande) - # Si la priorité de l'operande est plus faible que celle de l'opérateur - minor_priority = self.PRIORITY[self.get_main_op(operande)] < self.PRIORITY[operator] - # Si l'opérateur est - ou / pour after ou / ou ^ pour before - special = (operator in "-/" and posi == "after") or (operator in "/^" and posi == "before") - - return stand_alone and (minor_priority or special) - else: - return 0 - - def get_main_op(self, tokens): - """Getting the main operation of the list of tokens - - :param exp: the list of tokens - :returns: the main operation (+, -, * or /) or 0 if the expression is only one element - - """ - if hasattr(tokens, "mainOp"): - return tokens.mainOp - - if len(tokens) == 1: - # Si l'expression n'est qu'un élément - return 0 - - parStack = Stack() - main_op = [] - - for token in tokens: - if token == "(": - parStack.push(token) - elif token == ")": - parStack.pop() - elif self.isOperator(token) and parStack.isEmpty(): - main_op.append(token) - - return min(main_op, key = lambda s: self.PRIORITY[s]) - - ## --------------------- - ## Recognize numbers and operators - - @staticmethod - def isNumber( exp): - """Check if the expression can be a number which means int or Fraction - - :param exp: an expression - :returns: True if the expression can be a number and false otherwise - - """ - return type(exp) == int \ - or type(exp) == Fraction - #return type(exp) == int or type(exp) == Fraction - - @staticmethod - def isNumerande(exp): - """Check if the expression can be a numerande (not an operator) - - :param exp: an expression - :returns: True if the expression can be a number and false otherwise - - """ - return type(exp) == int \ - or type(exp) == Fraction - - def isOperator(self, exp): - """Check if the expression is in self.operators - - :param exp: an expression - :returns: boolean - - """ - return (type(exp) == Operator and str(exp) in self.operators) - -class flist(list): - """Fake list- they are used to stock the main operation of an rendered expression""" - pass