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C++ method that will parse an expression

 
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C++ method that will parse an expression, expression parsing
nano72
15 Sep, 2006 - 12:26 AM
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Hi guys ,

Anyone out there have a neat way to parse an arithmetic expression

It could be like command line expr ( A * B ) / 2
Now I have the Arithmetic methods written that is multiple and add

but need a neat way to parse the expression to pass the values into the Arithmetic methods ...

Any ideas out there .
all ideas appreciated
Thanks

This post has been edited by nano72: 15 Sep, 2006 - 12:29 AM
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Amadeus
RE: C++ Method That Will Parse An Expression
15 Sep, 2006 - 05:17 AM
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g++ -o drink whiskey.cpp
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Sorry to ask, but are you looking for help in creating such a parser, or do you want an exisiting one?
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nano72
RE: C++ Method That Will Parse An Expression
15 Sep, 2006 - 08:32 AM
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QUOTE(Amadeus @ 15 Sep, 2006 - 06:17 AM) *

Sorry to ask, but are you looking for help in creating such a parser, or do you want an exisiting one?


Well if there is a simple and neat one out there I would be grateful to integrate into my code .

what i have is the string been passed in for eg (vala* valb) / vala
need to parse it out taking into account precedence

the multiply and division methods are written

thanks
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Videege
RE: C++ Method That Will Parse An Expression
15 Sep, 2006 - 09:08 AM
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rêvant.toujours
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A sometimes not so simple way to do it is simply to write a parser that functions within a while loop, incrementing one character at a time and doing different things depending on the character; this usually involves a bunch of boolean switches and whatnot.

Another nifty way to do it is to construct a binary tree of expressions and parse the equation like an HP calculator does it. Check out an article describing this right here.
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nano72
RE: C++ Method That Will Parse An Expression
20 Sep, 2006 - 12:43 AM
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QUOTE(Videege @ 15 Sep, 2006 - 10:08 AM) *

A sometimes not so simple way to do it is simply to write a parser that functions within a while loop, incrementing one character at a time and doing different things depending on the character; this usually involves a bunch of boolean switches and whatnot.

Another nifty way to do it is to construct a binary tree of expressions and parse the equation like an HP calculator does it. Check out an article describing this right here.


Thanks for that -Is there any code that supports this so that i can integrate it into my program ?????????
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