Questions related to the parsing (and possibly the evaluation) of free-form mathematical expressions in strings, lists, or streams
2
votes
0answers
22 views
Optimize shunting-yard algorithm
Following your suggestions, I updated my expression evaluator with a Shunting-Yard algorithm.
I've created two classes, a Shunting-yard class and a RPNsolver class.
The first I mentioned converts ...
7
votes
1answer
81 views
Math expression evaluator
It is my second attempt to make a math expression evaluator.
To evaluate an expression, I created a class that works like this:
-it removes all the blank spaces
-if brackets are present, it ...
1
vote
1answer
42 views
Tokenize a mathematical statement string
The function tokenize generates tokens from a mathematical string.
It can chain characters together to form longer tokens.
This can be used to build a parse tree,...
6
votes
1answer
106 views
Creating truth table from a logical statement
This code creates a truth table from a statement in logic. The statement is input as a string, and it is identified as a tautology if it is true for all true and false combinations of the variables.
...
3
votes
1answer
70 views
NASM RPN Calculator
I've been learning Assembly over the past few days, and I've made a simple RPN calculator.
Here is the main logic of the program, excluding utility functions such as printing:
...
3
votes
1answer
170 views
Shunting-yard algorithm for expression parser
After reading about the Shunting-yard algorithm, I decided to try to make a expression parser, before trying to make a actual language parser, using it. The way i translated the algorithm into C++ ...
4
votes
1answer
196 views
Rust Console RPN Calculator
I've been trying to teach myself Rust, and I decided that a simple console calculator would be a good project to learn from.
...
3
votes
0answers
44 views
Parser for an bifurcation analysis tool
So during my thesis I used xppaut quite extensively. In the end there were some minor problems and I decided to have a look at the code, which was just released at github.
So after 30 years of on and ...
8
votes
1answer
492 views
A queue based calculator for basic math operations
Currently, I am interested in programming. I have programmed a calculator in C. Everything works, but I do not feel completely confident in my solution.
Are there any logic or efficiency issues with ...
5
votes
2answers
281 views
Postfix calculator
As part of my learning Java I'm doing various tasks I set myself - one such task is a postfix calculator. It seems to work with all tests I've given it, and I would really appreciate some review of ...
2
votes
1answer
61 views
Interpreting a basic math string
I've written code that will take any basic math sum input as a string (for instance, 2*3+4/4) and solve it. The way I achieve this is by splitting the string into ...
5
votes
3answers
126 views
A command-line calculator using infix to postfix in C++
I was in the mood for some C++ and decided to write a command line calculator, which understands addition, subtraction, multiplication and parentheses. See what I have:
main.cpp
...
3
votes
2answers
80 views
Evaluating a completely parenthesized arithmetic expression
I tried to solve the following problem in a programming challenge, but the verdict was time limit exceeded.
Completely parenthesized expression
Write a program that reads a completely ...
4
votes
2answers
97 views
Mathematical input parser
I made a simple math expressions solver that using a "for" loop iterates over all the characters and stores the numbers and signs in std::vector.
It give support for unlimited parentheses and does ...
1
vote
1answer
92 views
Math expression parser in JavaScript
I've written the second iteration of my math expression parser, utilising what I learned from the first attempt to make a more reliable, maintainable piece of code.
If anybody wants to see the first ...
2
votes
4answers
233 views
Reverse Polish Notation Evaluation in Java
I would like to hear feedback about my code both in term of improving efficiency if possible or using other data structures. Also go ahead and let me know about code styles/patterns.
...
3
votes
1answer
41 views
Mathematical equation syntax tree
I'm writing these pieces of code to parse expressions in the context of a dice rolling application for DnD. It's pretty much my first try using TypeScript and I'm ...
4
votes
4answers
207 views
Primitive console string calculator in C
Recenlty I have finished this primitive console string calculator in C. I need your balanced criticism, I'd like to know what I have to correct, remake and learn.
Permitted operations: ...
6
votes
1answer
94 views
Data structure for expression evaluation in Haskell
I've made a data structure for mathematical expressions. I want to parse mathematical expressions like:
\$x = 3\$
\$y = 4\$
\$z = x + y :\$
into an evaluated document like:
\$x = 3\$
\$y = 4\$
\$z =...
1
vote
0answers
35 views
Grouping all mathematical results using a number sequence with basic math operators
Not sure how to make the title smaller. I was reading the question A truly amazing way of making the number 2016 and some of the answers referred to programatically determining the answer set.
What ...
8
votes
3answers
291 views
If ComparisonIsTrue(thisPost, ComparisonOperator.NotEqualTo, goodCode) Then Me.Answer
This is a follow-on to a global enum for comparison operators. I wanted to pass a logical expression E.G. >= someValue as a parameter to a function, so I made an ...
5
votes
1answer
103 views
Parsing/RPN calculator algorithm
I decided to try and complete the Parsing/RPN calculator algorithm from Rosetta Code in Rust. I'm still learning Rust and would appreciate feedback on my code.
...
4
votes
3answers
134 views
Math eval function for Haskell
I recently finished reading Learn you a Haskell for great good!. Even though some topics are a bit over my head (Monads anyone?), I wanted to try my hand at a ...
3
votes
0answers
192 views
Expression parser using Shunting-yard algorithm
I've been working on a expression parser which will be part of another project (some sort of DSL). This parser basically uses the Shunting-yard algorithm, except for the case of parenthesis: here it ...
4
votes
1answer
2k views
Reverse Polish Notation Calculator in Java
I created a highly effective Reverse Polish Notation calculator using Java 8, but am uncertain if there are any better ways to handle the problem. Feedback on any evident taboos and bugs is greatly ...
8
votes
3answers
131 views
CodeWars mathematical expresion evaluator
I recently wrote the following code for a codewars.com kata for evaluating mathematical expressions. I've been writing ruby for years, but almost everything I do is for personal use and isn't shared,...
6
votes
1answer
140 views
Somewhat Advanced C++ Calculator
I am currently in the process of learning C++ from C++ Primer. I have found the exercises in this book to be somewhat dull in that they only test syntax and not reasoning. As such, I have recently ...
4
votes
1answer
274 views
Simple lexical analysis - basic calculator
I recently found an interesting series that describes the specifics of how interpreters and compilers work, explaining each step (with code) and encouraging the reader to do exercises.
My code is ...
0
votes
2answers
584 views
Infix to postfix implementation using a stack
I have implemented a "infix-to-postfix" function that takes as input a list representing the parsed expression, resulted from applying a certain regular expression to an expression, and I would like ...
5
votes
1answer
233 views
Basic arithmetic operations for a programming language
I have written a set of functions to compute basic mathematical operations for my own Java-based programming language. First I tokenize input from the source code file and store it in a String array. ...
-1
votes
2answers
120 views
Infix to postfix parser in java
Please review my Parser class. Should I declare map outside of convToPosfixQueue method?
...
10
votes
3answers
347 views
Parsing expression with exponents and evaluating
I'm programming a basic command line calculator in java that can parse expressions and evaluate them, does not handle brackets yet.
For example an expression: \$9+9/2^2*5-1\$.
At this point I can ...
2
votes
1answer
210 views
Postfix evaluation using a stack in c
I have written a program to evaluate a postfix expression using a stack. I had my stack implementation using a linked list reviewed here, so I am only including the header file here.
I have taken ...
4
votes
1answer
175 views
Infix to Postfix Formula Parser Java
I've written a program that takes a mathematical formula as an user input and converts it from infix to postfix.
It doesn't support negative numbers.
The program doesn't depend on the user having to ...
4
votes
1answer
333 views
Ad-hoc lexical scanner for a calculator language
Challenge:
Build an ad-hoc scanner for a calculator language.
Specifications:
The tokens for the language are as follows:
assign → :=
plus → +
minus → -
times → *
div → /
lparen ...
4
votes
2answers
149 views
Reverse Polish Notation in F#
In my question to learn F#, I've decided to get one step closer to creating a programming language, and implement this simple Reverse Polish Notation "interpreter" of sorts.
It does not allow for ...
3
votes
0answers
52 views
Expression parsing (arithmetic operators only)
As a self-learning project, I wrote an expression parser using the shunting yard algorithm in JavaScript. It's a larger part of what I plan to be a program for handling dice expressions in tabletop ...
11
votes
2answers
3k views
+, -, *, /, () expression calculator
In an effort to understand how compilers work, I wrote a simple expression calculator in C#. A CalculatorExpression takes an infix string, converts the infix string ...
10
votes
1answer
134 views
Mathematical expressions evaluator with callbacks, the architecture
This question goes hand in hand with another question about a mathematical expressions evaluator in C++. The other question is meant to be read first, this one is but a complement to expose the ...
10
votes
1answer
236 views
Mathematical expressions evaluator with callbacks, the logic
I hesitated quite a bit of time before posting this question since the code to review is more or less a monster (with regards to its size). It is a basic mathematical expressions evaluator, but with ...
7
votes
2answers
592 views
A (late) Simple Calculator
As I was looking through my past questions, I noticed my really old calculator question (here and here). Considering it looked like a huge mess, I decided to rewrite it. Coincidentally, the April 2015 ...
11
votes
3answers
936 views
CC C# calculator
This is my basic C# calculator; I'm sure there is much that can be improved. This design is based on Bjarne Stroustrup's C++ calculator, a purposely be-bugged version of which can be found at his ...
3
votes
2answers
495 views
Recursive math expression eval
It has been very hard to use recursion, but I think that it made the code shorter and cleaner.
...
8
votes
1answer
216 views
Parsing equations from stdin
The program should read equations from stdin, parse them and generate a matrix of the coefficient which represents the system.
Example:
...
6
votes
2answers
291 views
Calculator that parses S-expressions
This is my first program I can call 'something'. I would be glad to hear what you think of it, so I wouldn't pick up bad habits further on.
It catches errors, but requires numbers to be separated ...
4
votes
1answer
108 views
Evaluating an expression with integers, +, and *, as well as -, / - revision 3
The original question came from this web site.
Revision 1
Revision 2
And this is the third revision. I delete spaces and validate an equation before computing.
...
7
votes
2answers
3k views
Evaluating an expression with integers, +, and *, as well as -, /
There is a job interview question, and the source of the question is here.
The solution is pretty simple. We just need to split the input string by + and then by *. Then we compute products in a ...
3
votes
1answer
54 views
Reverse Polish Calculator in Go
I'm very new to Go (this is my first real program), and I was hoping to see if there was anything I was missing about the language or any ways to make it more idiomatic.
calculator.go
...
4
votes
4answers
79 views
Math expression on-the-fly interpreter
In the last few day, I wanted to sharpen my C skills a bit, so I wrote a math expression interpreter that can handle + - * / ( ) and only integers.
I just want to know how good this code is, if ...
1
vote
1answer
4k views
Order of operations algorithm for calculator
I wrote a simple calculator which uses orders of operations. I would like to know, do you see any serious flaws in logic and what do you think about this solution?
It is my second approach to a ...
