Questions tagged [parsing]
This tag denotes challenges where parsing input is a large / the main part of the challenge.
223
questions
11
votes
16answers
690 views
Cartesian literal notation
Introduction
In computer science, a literal is a notation for representing a fixed value in source code. Almost all programming languages have notations for atomic values, some also have notations ...
25
votes
19answers
2k views
Convert prefix to infix
Infix notation is a method of printing mathematical expressions where each operator sits between its two arguments, such as \$ \left(5 \cdot 4\right) + 3 \$.
Prefix notation is a method of printing ...
2
votes
2answers
87 views
Tips for parsing Standard Input in JavaScript
I've been doing quite a few code golf recently and I realised that a lot of times, I have to do something involving list.
Most of the times lists are space-separated or comma-separated values in the ...
28
votes
27answers
2k views
Open or Close the Parentheses
Every phone needs a calculator app. Because of the limited screen real estate, the developer of mine has decided to save some buttons. Instead of having two dedicated bracket buttons - one for open <...
17
votes
12answers
1k views
How many values of this type?
Background
The number of values for a given type is called the cardinality of that type, and that of type T is written as |T|.
Haskell and a few other languages ...
18
votes
22answers
2k views
Parentheses Clusters
Write a program that groups a string into parentheses cluster. Each cluster should be balanced.
Examples :
...
14
votes
8answers
903 views
Simplify K projections
Background
K functions have a feature called projection, which is essentially partial application of values to a function. The syntax for projections is a natural extension of the regular function ...
19
votes
29answers
2k views
Remove oddly nested substrings
Task:
Input will consist of some text, with nested [] separating some of it into nested groups:
...
10
votes
4answers
328 views
Parse Ternary Lambda Calculus for correctness
Wheat Wizard has once tried to come up with a parsing problem unsuitable for regex, but it failed due to Anders Kaseorg's Perl regex answer. This is the second attempt. Now that we know that Perl ...
21
votes
5answers
1k views
Parse a lambda for correctness
The goal of this challenge is to fill a niche that is mostly lacking on this site. In my observations there most parsing verification challenges fall into two categories:
Super easy parsing. This ...
19
votes
5answers
821 views
What if function application was right-associative?
Background
In Haskell and many other functional languages, function application f(x) is simply written as f x. Also, this form ...
25
votes
17answers
1k views
r flag my Vyxal
Vyxal is a stack-based language, meaning that everything operates by popping and pushing values onto a stack. It has a bunch of useful flags, one of which is r.
...
12
votes
4answers
563 views
Leave the times out!
Everyone knows, that you can leave out the multiplication symbol (\$\times\$, or *) in
a*b
...
5
votes
3answers
164 views
Distribute the additions!
Challenge: Given an expressions made of additions and multiplications, output an expression that is a sum of products. The output must be equivalent to the input modulo the law of distribution. For ...
52
votes
11answers
4k views
Write a C++ demangler
If you have ever looked at an objdump of a C++ program, you have likely seen something like this:
_ZN3foo3bar3bazI6sampleEE3quxvi3foo
This is a C++ mangled symbol, ...
12
votes
8answers
2k views
Visualize a Risky program
Risky is a new language of mine, which features an interesting form of tacit programming. In this challenge, you'll take a Risky program as input, and visualize the parsing.
No knowledge of Risky is ...
15
votes
14answers
997 views
Evaluation order of an APL n-train
From Codidact with permission.
Description
APL trains are a series of functions, that get applied to an argument in this way:
(f g) x = f g x here ...
19
votes
11answers
4k views
I'm Lazy: Close my Superparens
Picolisp has a feature called "super parentheses":
Brackets ('[' and ']') can be used as super parentheses. A closing bracket will match [all parentheses to and including] the innermost ...
13
votes
8answers
943 views
What is the link to your answer?
Goal
Your task is to create a program taking no input that returns the link to your answer. You can find a link to your answer by clicking at the share button on your answer.
Rules
Standard loopholes ...
8
votes
1answer
267 views
CDGLF: TMN to APL
In this challenge you will remove one of my least favorite features, operator precedence from traditional math notation, to acheive the syntax of one of my favorite languages, APL. The APL subset we ...
10
votes
0answers
330 views
Golfing Expressions
We can write mathematical expressions using the standard math operators (,),+,...
11
votes
6answers
466 views
Approx how many search results
When one performs a search query using Google, one of the first things you see is an approximation of how many results were found. Today, you'll be simulating this in as few bytes as possible.
Input
A ...
7
votes
5answers
717 views
Does this JavaScript function support keyword arguments?
JavaScript has no direct support for keyword arguments, but it supports argument object destructuring. It is standard to use a destructed final argument for keyword arguments. Here is an example:
<...
28
votes
10answers
2k views
Help Stack Exchange transpose tables
Stack Exchange doesn't know how to transpose tables. Let's help.
Given a markdown table, transpose it.
Input assumptions:
There will be at least two rows (including header) and two columns
Either all ...
22
votes
18answers
1k views
Interpret Interval Notation
Interval notation is a way to write complicated range bounds more conveniently and concisely than writing an inequality. The challenge, should you choose to accept it, is to write a program or ...
14
votes
8answers
1k views
How Many Atoms?
How Many Atoms?
Write the shortest code that when given a chemical formula as input, outputs the total number of atoms in the formula.
Input
A chemical formula in any reasonable format. Each chemical ...
8
votes
6answers
706 views
(1) Determine the amount of statues
Inspired by this stack of little statues that are currently on my desk at work, given to me by my colleagues from Sri Lanka when they visited The Netherlands:
This is split into two different ...
7
votes
2answers
238 views
(2) Can the statues be stacked?
Inspired by this stack of little statues that are currently on my desk at work, given to me by my colleagues from Sri Lanka when they visited The Netherlands:
This is split into two different ...
11
votes
21answers
3k views
Advent of Code 2020, Day 2, Part 1
Today, my girlfriend and I started with this year's Advent of Code to improve our Python. So far we only did Day 1 and the first part of Day 2. The latter, I found to be very fun, so, to spice it up a ...
6
votes
3answers
591 views
Day of Week - Natural language processing and date parsing
You'll get a human-readable question matching one of the following syntaxes, and are expected to print/return the corresponding result. Finding similarities between the human-readable inputs and ...
10
votes
6answers
817 views
Parse a Scala expression
Scala isn't a very commonly used language around here. Most of those who know it like it[citation needed], but some go :\ when they encounter its user-defined ...
3
votes
4answers
1k views
Parse a nested parentheses
Objective
Mimic Haskell's reads :: ReadS ().
Or in other words, parse nested parentheses. Since the target type is () (the type ...
16
votes
27answers
2k views
Compactify the query string
Introduction
Just on Hacker news, John Resig contemplates
transforming a query “foo=1&foo=2&foo=3&blah=a&blah=b” into one that looks like this: “foo=1,2,3&blah=a,b", https://...
12
votes
7answers
616 views
De-interleave log lines: HARD MODE
In the face of some regrettable rules that turned the original into a glorified sorting task, I am posting a more challenging variant. Shout out to Luis Mendo for the suggestion of how to improve the ...
17
votes
21answers
2k views
De-interleave log lines [duplicate]
You've inherited a server that runs several apps which all output to the same log.
Your task is to de-interleave the lines of the log file by source. Fortunately, each line begins with a tag that ...
26
votes
21answers
4k views
13
votes
3answers
1k views
Implement a UNIX file system and command line parser
Description
Your task is to implement a simple UNIX command parser and file system. Your program will have to implement a file system that can be modified via commands.
The starting directory of your ...
14
votes
12answers
3k views
Parse a Unicode vulgar fraction
Objective
Given a string with single Unicode vulgar fraction, parse it to a rational number.
Valid inputs
A valid input is one of:
¼ U+00BC; one quarter
...
10
votes
1answer
174 views
Explicit-ify APL expressions involving trains
Related: Clearly parenthesize APL trains
Background
In the most basic form, APL has two kinds of tokens: arrays and functions. For this challenge, we will use a lowercase letter ...
35
votes
14answers
4k views
Maintain Social Distancing!
Task
Given the situation with this global pandemic, you've been enlisted to help maintain social distancing. Your challenge, should you choose to accept it, is to write a program that takes in the ...
14
votes
6answers
615 views
Parse a variable star designation
The variable star designation is an identifier for a variable star (a star that fluctuates in brightness). It consists of either a 1-2 letter code or (when the letter code is no longer sufficient) a '...
14
votes
4answers
594 views
Keta Bracket Autocompletion
Special thanks to Bubbler and AdmBorkBork for supplying feedback about this challenge
Keta (Keyboard tacit — clever naming, I know!) is a golfing language I’ve been working on recently. One of it’s ...
6
votes
0answers
280 views
Count the length of head movement
Once upon a time I wanted to order custom tokens for a board game. They say they can do it, and then they present me their price list. I was confused because they charge per inch of head movement, and ...
7
votes
4answers
355 views
Shorthand Combined Functions
I was doing some investigation into trig functions using compound angles recently, and noticed that the results are really long and tedious to write:
$$
\cos(A+B) = \cos A \cos B - \sin A \sin B \\
\...
14
votes
8answers
518 views
Output integer given a digital clock style input
Input
_ _ _ _ _ _ _ _
| _| _||_||_ |_ ||_||_|| |
||_ _| | _||_| ||_| _||_|
output
1234567890
Rules
...
13
votes
1answer
389 views
Duct Tape a Regex Decider
Your task is to create a program that determines whether a given string is a valid regular expression or not using code snippets sourced from sites on the StackExchange network.
For the purposes of ...
13
votes
2answers
368 views
Interpreter for number theory, modulo n
A sentence of number theory (for our purposes) is a sequence of the following symbols:
0 and ' (successor) - successor means <...
11
votes
16answers
2k views
MQTT subscription topic match
Background
MQTT (Message Queuing Telemetry Transport) is an ISO standard publish-subscribe-based messaging protocol (Wikipedia).
Each message has a topic, such as the following examples:
...
18
votes
9answers
824 views
Jimmy needs a new pair of shoes!
Jimmy has had a busy last week with all these platforms and ropes, and poor Jimmy doesn't even have legs or feet to stand on!
Your job is to take a string containing multiple Jimmys and give them ...
23
votes
27answers
7k views
Can Jimmy hang on his rope?
Yet another Jimmy challenge by his original father. See these other lovely challenges.
As you all know, recently we've been seeing challenges related to Jimmy on platforms. Now, Jimmy is an acrobat ...
