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Evalating Expressions

Posted: Tue Nov 18, 2014 4:31 am
by vignezds
Hello Everyone,
I am Very much new to LISP, I don't have basic knowledge in LISP but I supposed to do project in LISP. I need to evaluate given expression(Just addition, Subtraction, Multiplication, Division), kindly help me to do this. I am using LISPWORKS as tool.

Re: Evalating Expressions

Posted: Tue Nov 18, 2014 8:19 am
by Goheeca
You don't even specify the input!
However, I provide a generel answer.

If you have an arithmetic expression in s-expr form, you can easily evaluate it:

Code: Select all

(defvar arithmetic-expression '(+ 1 (* 5 6)))
(eval arithmetic-expression) ; = 31
For the standard infix notation of arithmetic expression, feel free to look at general description of Shunting yard algorithm.

Re: Evalating Expressions

Posted: Tue Nov 18, 2014 8:25 am
by Goheeca
And on Rosetta Code, you have an implementation in CL of the arithmetic expression evaluation. Consider it as an inspiration only.

Re: Evalating Expressions

Posted: Thu Nov 20, 2014 11:15 am
by vignezds
Thank you so much, I got complete idea over it.
Goheeca wrote:And on Rosetta Code, you have an implementation in CL of the arithmetic expression evaluation. Consider it as an inspiration only.