infix-notation

I've written a few methods for a calculator. One, which evaluates an entered Postfix expression and another, which transfers an entered infix expression into a postfix expression. Both these methods allow multi digit integers aswell as floats for the number input types. Now for my question: I want to include the negative input in both these methods e.g. Infix: "3 * (-1)". However I'm kinda lacking an idea on how to implement this problem. Maybe someone can give me ideas or code examples. I'm including both methods below. A few simple methods are used in them which aren't shown here, but most

I read book today. It introduced algorithm about chaning from infix to postfix.. What is benefits? Thanks in advance. Well for one, you can easily evaluate a postfix expression in a single scan from left to right with the help of a stack, unlike evaluating infix expressions. and second, there is no need of the concept of parentheses and precedence rules etc. in a postfix expression. I think infix is really easy to understand for human. Postfix is the good way for machine to process. Please prefer: http://www.cs.man.ac.uk/~pjj/cs2121/fix.html An advanced example that also illustrates the

I need a function that takes an infix string (like "3 + 4 * 9"), and convert it to postfix (like "4 9 * 3 +"). I got it working until you throw in parentheses within parentheses. I've been working on it all day and can't figure out what I'm doing wrong- can someone with a fresh mind see it, maybe? I feel like I'm really close! Thanks! Here's the code: string ExpressionManager::infixToPostfix(string infixExpression) { cout << "itop Testing : " << infixExpression << endl; string posnums = "0123456789"; string posops = "+-*/%(){}[]"; string onlyops = "+-/%*"; string space = " "; string openbra =

A mathematical expression is usually expressed in infix notation. For evaluation purposes, we can change it to postfix (reverse polish) notation (using algorithms like Shunting-Yard ) and then evaluate the postfix notation using stack. I found out that calculators use this technique, but do today's modern compilers use this for arithmetic expression evaluation? Is it efficient enough or other techniques (or algorithms) are being used? To answer this question let's focus on the concepts you mention, infix notation , Shunting-Yard and evaluation and then relate them to compiling. To start with

Consider the following scenario: I have a class Test class Test() { infix fun say(msg: String) = println(msg) } and a main method fun main(args: Array<String>) { val test = Test() test say "Hello World!" //Works with(test) { say "Goodbye World!" //Does not work say("Hello again!") //Works } } As you can see I'm testing out the infix notation. Considering with(...) allows you to work with the object passed as parameter in the with block without having to access its members through the dot notation, I would expect the infix notation to work like I show in my example above. Unfortunately this