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Questions tagged [polish-notation]

Polish notation, also known as Polish prefix notation or simply prefix notation, is a form of notation for logic, arithmetic, and algebra. Its distinguishing feature is that it places operators to the left of their operands. This tag and [tag:prefix-notation] are really synonyms.

Polish notation, also known as Polish prefix notation or simply prefix notation, is a form of notation for logic, arithmetic, and algebra. Its distinguishing feature is that it places operators to the left of their operands. If the arity of the operators is fixed, the result is a syntax lacking parentheses or other brackets that can still be parsed without ambiguity. The Polish logician Jan Łukasiewicz invented this notation in 1924 in order to simplify sentential logic.

The term Polish notation is sometimes taken (as the opposite of infix notation) to also include Polish postfix notation, or Reverse Polish notation, in which the operator is placed after the operands.

When Polish notation is used as a syntax for mathematical expressions by interpreters of programming languages, it is readily parsed into abstract syntax trees and can, in fact, define a one-to-one representation for the same. Because of this, Lisp (see below) and related programming languages define their entire syntax in terms of prefix notation (and others use postfix notation).

Wikipedia: http://en.wikipedia.org/wiki/Polish_notation

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Why postfix (rpn) notation is more used than prefix?

By use I mean its use in many calculators like HP35- My guesses (and confusions) are - postfix is actually more memory efficient -( SO post comments here ). (confusion - The evaluation algorithm of both are similar with a stack) keyboard input…
Amartya
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How to count number of arguments of a method while converting infix expression to reverse polish notation

I have an expression like below. MIN(MAX(AVG(AVG(4,2),2,3),SUM(1,2))) I have implemented shunting yard algorithm to convert infix to reversed polish notation. I add the function MAX , MIN and AVG with two arguments. But suppose if I want to…
Bankelaal
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Merge two arraylists in a simple form of Polish Notation

I have two arraylists of type String, one of Operands and one of Operators ArrayList operands = new ArrayList(); ArrayList operators = new ArrayList(); They are filled like so operands = { "\"symbol\": \"CHKP%\"",…
Kyte
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I don´t understand Normal Polish Notation (NPN or PN). How to build a complex domain in Odoo?

Could someone translate the following polish notation to its SQL counterpart: ['|', '&', ('is_company','=', True),('parent_id', '=', False),('company_name', '!=', False),('company_name', '!=', '')] My guess is : is_company = True OR parent_id =…
Lekhnath
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Making a concatenative Haskell variant: precedence of application and composition

I'm learning the basics of concatenative languages, whose original idea is that function name concatenation is the same as function composition, instead of being function application as in Haskell. Joy, Forth or Factor are postfix, which means…
enrique
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convert a prefix expression to infix expression using javaScript

I am really struck with a question . convert the below expression using javaScript [ "AND", ["<", "var1", "var2"], [ "OR", [">", "var3", "var4"], ["==", "var5", "var6"] ] to var1 < val2 AND (var3 > val4 OR val5 == val6) Sorry that, I dont have…
Sulu.MeanStack
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Chainable/N-ary operations support in Prefix/Polish Notation Trees

Prefix Notation conversion into a tree is usually done like this: Create a binary tree from an algebraic expression However, I need to support so called chainable operations that have more than two operands. If that operation is splittable i.e (+ a…
Koronis
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Polish/Prefix Notation logical expression to Expression Tree and back

I am looking for a java library that could convert a logical expression wirtten in polish/prefix notation into an abstract syntax tree object and back. This is the syntax used by the SMT-LIB standard and CVC4 and I am trying to create some complex…
Koronis
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Postfix Expressions advantages?

What are advantages of post-fix expressions over prefix expressions? What can be the disadvantages of prefix expressions that can be removed using postfix expressions?
Sameer Katti
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Convert expression to polish notation in Scala

I would like to convert an expression such as: a.meth(b) to a function of type (A, B) => C that performs that exact computation. My best attempt so far was along these lines: def polish[A, B, C](symb: String): (A, B) => C = { (a, b) => //…
Radu Stoenescu
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How to understand the F function in Burks/Warren/Wright's Lukasiewicz Logic Machine

From the bibliography of chapter 1 of the 1962 A Programming Language, I found this intriguingly concise description of a forward-Polish (Lukasiewicz) Logic Machine. And I think I'm with it up to this part on the Logic Function F: What does (2a)…
luser droog
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how to manage polish(poland) strings with stored procedure in mysql

I am facing issue with polish characters inside mysql stored procedure. String is following : Premium American Twill -rozmiar dziecięcy -z naklejką SNAP BACK PRO Getting following Error : Incorrect string value: '\xC4\x99cy -...' for column…
Mohit Shah
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Why is my program entering a while loop when the condition is false?

When I input a string operator whether it be addition(+), subtraction(-), multiplication(*), division(/) or module(%), it still enters the while loop even when I enter a valid input. I don't know what the problem could be because the while loop is…
Majestic
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Python recursive function or cycle to convert string to json logical object

I have this function: def req_splitter(req_string): req = {} if " AND " in req_string: cond = "AND" req_splitted = req_string.split(" AND ") elif " OR " in req_string: cond = "OR" req_splitted =…
Nylithius
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Interpreter recursive Polish Notation with tokens list

I have interpreter that solve Polish notation. I have all operations and numbers in tokens and I have a list of tokens. So for example - - 5 4 2 is a list with these tokens: SubtractionToken, SubtractionToken, NumberToken, NumberToken,…
Blabla
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