# Reports:Tasks not implemented in Common Lisp

**Awareness**

If

**Common Lisp**is a language you like, or are interested in, please inform your fellow members of the Common Lisp community; this page can't be emptied without your and their participation.

## Contents

## Not implemented[edit]

These are currently not implemented in Common Lisp. Please implement some if you can. If any tasks are not possible or too complex in Common Lisp, they should not be on this list. To mark a task as such, add **{{omit from|Common Lisp}}**, preserving the capitalization of the language, to that task. It will appear below under the "Not Considered" section.

### A

- ASCII art diagram converter
- Abbreviations, easy
- Abbreviations, simple
- Abelian sandpile model
- Abundant odd numbers
- Active Directory/Connect
- Active Directory/Search for a user
- Active object
- Angles (geometric), normalization and conversion
- Anti-primes
- Approximate Equality
- Arena storage pool
- Associative array/Merging
- Attractive numbers
- Average loop length
- Averages/Mean time of day

### B

- Base64 decode data
- Bell numbers
- Bioinformatics/Sequence mutation
- Bioinformatics/base count
- Bitcoin/address validation
- Bitcoin/public point to address
- Bitmap/Bézier curves/Cubic
- Bitmap/Bézier curves/Quadratic
- Bitmap/Flood fill
- Bitmap/PPM conversion through a pipe
- Bitmap/Read an image through a pipe
- Box the compass
- Brazilian numbers

### C

- Canny edge detector
- Cantor set
- Carmichael 3 strong pseudoprimes
- Catmull–Clark subdivision surface
- Chaocipher
- Chat server
- Check Machin-like formulas
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Chowla numbers
- Church Numerals
- Circles of given radius through two points
- Colour bars/Display
- Colour pinstripe/Printer
- Commatizing numbers
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Convex hull
- Create a file on magnetic tape
- Create an object at a given address
- Cuban primes
- Currency

### D

- Date manipulation
- De Bruijn sequences
- Death Star
- Deconvolution/2D+
- Deming's Funnel
- Department Numbers
- Determine if a string has all the same characters
- Determine if a string has all unique characters
- Determine if a string is collapsible
- Determine if a string is squeezable
- Determine if only one instance is running
- Dinesman's multiple-dwelling problem
- Discordian date
- Distributed programming
- Doubly-linked list/Traversal
- Draw a clock
- Draw a cuboid
- Draw a pixel
- Draw a rotating cube
- Draw a sphere
- Dutch national flag problem

### E

### F

- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Fairshare between two and more
- Fermat numbers
- Fibonacci word/fractal
- File extension is in extensions list
- Find common directory path
- Find largest left truncatable prime in a given base
- Find the intersection of two lines
- First class environments
- First perfect square in base N with N unique digits
- First power of 2 that has leading decimal digits of 12
- Fixed length records
- Flipping bits game
- Flow-control structures
- Floyd-Warshall algorithm
- Four is the number of letters in the ...
- Fraction reduction
- Functional coverage tree
- Fusc sequence

### G

### H

### I

### K

### L

### M

- Mad Libs
- Magic squares of doubly even order
- Magic squares of singly even order
- Main step of GOST 28147-89
- Mastermind
- Matrix chain multiplication
- Mayan numerals
- Maze solving
- McNuggets Problem
- Median filter
- Memory layout of a data structure
- Mertens function
- Metallic ratios
- Metered concurrency
- Mian-Chowla sequence
- Mind boggling card trick
- Minimal steps down to 1
- Morse code
- Multi-dimensional array
- Multiplicative order
- Multisplit
- Munching squares
- Mutex

### N

### P

- P-value correction
- Palindromic gapful numbers
- Paraffins
- Parametrized SQL statement
- Parse an IP Address
- Partition an integer X into N primes
- Pascal's triangle/Puzzle
- Pathological floating point problems
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Penney's game
- Pentagram
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Perfect totient numbers
- Permutations/Derangements
- Permutations/Rank of a permutation
- Pierpont primes
- Pinstripe/Display
- Pinstripe/Printer
- Play recorded sounds
- Plot coordinate pairs
- Poker hand analyser
- Polyspiral
- Prime conspiracy
- Primes - allocate descendants to their ancestors
- Problem of Apollonius
- Pythagoras tree
- Pythagorean quadruples

### R

- RPG Attributes Generator
- Ramanujan's constant
- Ramer-Douglas-Peucker line simplification
- Range consolidation
- Ranking methods
- Rare numbers
- Recaman's sequence
- Reflection/Get source
- Reflection/List methods
- Reflection/List properties
- Rendezvous
- Resistor mesh
- Retrieve and search chat history
- Rock-paper-scissors
- Rosetta Code/Count examples
- Rosetta Code/Find bare lang tags
- Rosetta Code/Find unimplemented tasks
- Rosetta Code/Fix code tags
- Rosetta Code/Rank languages by popularity

### S

- SOAP
- SQL-based authentication
- Safe addition
- Safe primes and unsafe primes
- Sailors, coconuts and a monkey problem
- Same Fringe
- Scope/Function names and labels
- Secure temporary file
- Send email
- Sequence: nth number with exactly n divisors
- Sequence: smallest number greater than previous term with exactly n divisors
- Sequence: smallest number with exactly n divisors
- Sequence of primorial primes
- Set puzzle
- Sexy primes
- Shoelace formula for polygonal area
- Shortest common supersequence
- Sierpinski pentagon
- Sierpinski triangle/Graphical
- Simulate input/Keyboard
- Smarandache prime-digital sequence
- Smith numbers
- Sokoban
- Solve a Hidato puzzle
- Solve a Holy Knight's tour
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Solve the no connection puzzle
- Sort numbers lexicographically
- Sort three variables
- Sorting algorithms/Patience sort
- Sorting algorithms/Radix sort
- Special characters
- Speech synthesis
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Square-free integers
- Square but not cube
- Stable marriage problem
- Start from a main routine
- State name puzzle
- Statistics/Basic
- Statistics/Normal distribution
- Stem-and-leaf plot
- Stirling numbers of the first kind
- Stirling numbers of the second kind
- Straddling checkerboard
- Stream Merge
- Strip block comments
- Strong and weak primes
- Successive prime differences
- Suffixation of decimal numbers
- Sunflower fractal
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping

### T

- Table creation/Postal addresses
- Tarjan
- Taxicab numbers
- Terminal control/Coloured text
- Terminal control/Cursor movement
- Terminal control/Cursor positioning
- Terminal control/Dimensions
- Terminal control/Inverse video
- Terminal control/Positional read
- Test a function
- Test integerness
- Text processing/2
- Textonyms
- The Name Game
- Tonelli-Shanks algorithm
- Topic variable
- Topswops
- Total circles area
- Totient function
- Truncate a file
- Truth table

### U

### V

### W

### Draft tasks without implementation[edit]

These tasks are drafts, meaning they largely need more work to turn them into full tasks. Perhaps you can help by trying to implement them in Common Lisp (after all, one of the key requirements for a task being non-draft is multiple implementations, preferably in widely different languages) but be aware that this may be difficult because of lack of definition of the task itself.

### 2

### A

### B

### C

- Card shuffles
- Chebyshev coefficients
- Checksumcolor
- Chemical Calculator
- Chess player
- Chess player/Move generation
- Chess player/Program options and user interface
- Chess player/Search and evaluation
- Cipolla's algorithm
- Code segment unload
- Color wheel
- Combinations with repetitions/Square Digit Chain
- Compiler/ Verifying Syntax
- Continued fraction/Arithmetic/G(matrix NG, Contined Fraction N)
- Continued fraction/Arithmetic/G(matrix NG, Contined Fraction N1, Contined Fraction N2)
- Copy stdin to stdout
- Create an object/Native demonstration
- Curve that touches three points
- Cycle detection
- Cyclotomic Polynomial

### D

### E

### F

- Factorions
- Faulhaber's formula
- Faulhaber's triangle
- Feigenbaum constant calculation
- Fibonacci heap
- Fibonacci matrix-exponentiation
- File size distribution
- Find URI in text
- Find duplicate files
- Find first and last set bit of a long integer
- Find the intersection of a line with a plane
- Finite state machine
- Fivenum
- Free polyominoes enumeration
- French Republican calendar

### G

### H

### I

### L

### M

### N

### P

- Palindrome dates
- Parse EBNF
- Parse command-line arguments
- Particle Swarm Optimization
- Penrose tiling
- Pentomino tiling
- Perceptron
- Permutations with repetitions
- Permutations with some identical elements
- Playfair cipher
- Polynomial synthetic division
- Primalty by Wilson's theorem
- Print debugging statement
- Process SMIL directives in XML data
- Proof

### R

- Railway circuit
- Ramsey's theorem
- Random Latin Squares
- Raster bars
- Readline interface
- Recursive descent parser generator
- Remote agent/Agent interface
- Remote agent/Agent logic
- Remote agent/Simulation
- Resistance Calculator
- Resistance Network Calculator
- Reverse the gender of a string
- Robots
- Rosetta Code/List authors of task descriptions
- Rosetta Code/Rank languages by number of users
- Rosetta Code/Run examples
- Rosetta Code/Tasks sorted by average lines of code
- Rosetta Code/Tasks without examples
- Run as a daemon or service

### S

- Safe mode
- Sattolo cycle
- Selective File Copy
- Self-hosting compiler
- Separate the house number from the street name
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Snake
- Snake And Ladder
- Solve a Rubik's Cube
- Solving coin problems
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Cycle sort
- Sorting algorithms/Tree sort on a linked list
- Spoof game
- Starting a web browser
- Subset sum problem
- Substitution Cipher
- Suffix tree
- Sum data type

### T

- Table creation
- Tamagotchi emulator
- Teacup rim text
- Terminal control/Restricted width positional input/No wrapping
- Terminal control/Restricted width positional input/With wrapping
- Tetris
- Text between
- Text to HTML
- Time-based One-time Password Algorithm
- Topological sort/Extracted top item
- Transportation problem
- Tree datastructures
- Two Sum
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Common Lisp, but somebody, somewhere, decided that the example implementation was faulty or in some other way requiring attention. If you're familiar with the task and language, please consider reviewing/correcting the example and removing the notice.

### Other pages[edit]

These are other pages related to Common Lisp which require attention; with your knowledge and assistance, we can improve the quality of the site's content.

### No pages found.

## Not Considered[edit]

These tasks are not generally counted toward "unimplemented", as somebody, somewhere, decided that Common Lisp was inappropriate for these tasks, or implementations of them would be unenlightening. Feel free to try your hand at them anyway.

### No pages found.

## End of List[edit]

Again, feel free to try your hand at any of the tasks listed on this page.