Thread: Parsing a formula

  1. #1
    Registered User
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    Feb 2006
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    Parsing a formula

    Hello everyone,

    I need assistance in parsing a mathematical formula that is input by the user. Say a user inputs the following; 4*(370-345)+12.

    How would I go about parsing such a string? We would have no idea how many numbers or operations the person enters, within a set character limit.

    Any hints would be much appreciated. Thanks in advance.

  2. #2
    Registered User
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    Jun 2004
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    Maybe you should take a look on this http://www.gnu.org/software/bison/ maybe it is too much for what you need but at least a look won't hurt.

  3. #3
    ex-DECcie
    Join Date
    Dec 2005
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    Quote Originally Posted by ashkya
    Hello everyone,

    I need assistance in parsing a mathematical formula that is input by the user. Say a user inputs the following; 4*(370-345)+12.

    How would I go about parsing such a string? We would have no idea how many numbers or operations the person enters, within a set character limit.

    Any hints would be much appreciated. Thanks in advance.

    Off the top of my head, you'd need to pull it all into a string. You'd need to know your operators (*,+,-,parens) and find them.... I'd say the stuff before, after and between the operators are the things you'd probably figure are numbers.

    I might be wrong, but at least it might get you going in the right direction.....
    Mr. Blonde: You ever listen to K-Billy's "Super Sounds of the Seventies" weekend? It's my personal favorite.

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