# Reports:Tasks not implemented in Factor

**Awareness**

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## Contents

## Not implemented[edit]

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

### A

- ASCII art diagram converter
- AVL tree
- Abelian sandpile model
- Achilles numbers
- Active Directory/Connect
- Active Directory/Search for a user
- Append a record to the end of a text file
- Apply a digital filter (direct form II transposed)
- Archimedean spiral
- Arena storage pool
- Arithmetic-geometric mean/Calculate Pi
- Atomic updates

### B

### C

- Call a function in a shared library
- Canny edge detector
- Casting out nines
- Catmull–Clark subdivision surface
- Chaos game
- Chat server
- Check input device is a terminal
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Cholesky decomposition
- Church numerals
- Closest-pair problem
- Color of a screen pixel
- Color quantization
- Color wheel
- Colour pinstripe/Printer
- Combinations with repetitions
- Compare length of two strings
- Compare sorting algorithms' performance
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Composite numbers k with no single digit factors whose factors are all substrings of k
- Convex hull
- Conway's Game of Life
- Create an object at a given address
- Cullen and Woodall numbers
- Cut a rectangle
- Cyclotomic polynomial

### D

- De Bruijn sequences
- Death Star
- Deconvolution/1D
- Deconvolution/2D+
- Delegates
- Determine if only one instance is running
- Determine if two triangles overlap
- Dijkstra's algorithm
- Dining philosophers
- Discordian date
- Display an outline as a nested table
- Doubly-linked list/Definition
- Doubly-linked list/Element insertion
- Doubly-linked list/Traversal
- Draw a clock
- Draw a rotating cube

### E

- Earliest difference between prime gaps
- Eertree
- Elementary cellular automaton/Infinite length
- Elementary cellular automaton/Random Number Generator
- Elliptic Curve Digital Signature Algorithm
- Elliptic curve arithmetic
- Equal prime and composite sums
- Euler's constant 0.5772...
- Events
- Execute a Markov algorithm

### F

- FTP
- Faces from a mesh
- Find duplicate files
- Find largest left truncatable prime in a given base
- Fixed length records
- Flipping bits game
- Flow-control structures
- Floyd-Warshall algorithm
- Formal power series
- Four bit adder
- Four is the number of letters in the ...
- Fractal tree
- Fraction reduction
- French Republican calendar
- Function prototype
- Functional coverage tree

### G

### H

### I

### K

### L

- LU decomposition
- LZW compression
- Langton's ant
- Last letter-first letter
- Latin Squares in reduced form
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- Legendre prime counting function
- Levenshtein distance/Alignment
- List rooted trees
- Longest increasing subsequence
- Longest string challenge
- Lucky and even lucky numbers
- Lychrel numbers

### M

- MD4
- MD5/Implementation
- Machine code
- Magic squares of singly even order
- Main step of GOST 28147-89
- Man or boy test
- Mastermind
- Matrix chain multiplication
- Matrix digital rain
- Mayan calendar
- Maze generation
- Maze solving
- Median filter
- Memory layout of a data structure
- Merge and aggregate datasets
- Metaprogramming
- Miller–Rabin primality test
- Minesweeper game
- Minimal steps down to 1
- Minimum multiple of m where digital sum equals m
- Monty Hall problem
- Multiple regression
- Musical scale

### N

### P

- P-Adic numbers, basic
- P-Adic square roots
- P-value correction
- Pancake numbers
- Paraffins
- Parallel brute force
- Parameterized SQL statement
- Parse an IP Address
- Parsing/RPN to infix conversion
- Parsing/Shunting-yard algorithm
- Particle fountain
- Pattern matching
- Peaceful chess queen armies
- Pell numbers
- Pentagram
- Pentomino tiling
- Percentage difference between images
- Percolation/Bond percolation
- Peripheral drift illusion
- Permutation test
- Permutations/Rank of a permutation
- Permutations by swapping
- Pig the dice game
- Pig the dice game/Player
- Pinstripe/Display
- Pinstripe/Printer
- Plasma effect
- Play recorded sounds
- Playfair cipher
- Pointers and references
- Polynomial regression
- Polyspiral
- Prime triangle
- Primes - allocate descendants to their ancestors
- Problem of Apollonius
- Pythagoras tree
- Pythagorean quadruples

### R

- RCRPG
- RSA code
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random sentence from book
- Rare numbers
- Rate counter
- Read a configuration file
- Recaman's sequence
- Record sound
- Remove lines from a file
- Rendezvous
- Repunit primes
- Resistor mesh
- Respond to an unknown method call
- Retrieve and search chat history
- Roots of a function
- Rosetta Code/Find bare lang tags
- Rosetta Code/Find unimplemented tasks
- Rosetta Code/Fix code tags
- Rosetta Code/Rank languages by number of users
- Rosetta Code/Rank languages by popularity
- Runge-Kutta method

### S

- SOAP
- SQL-based authentication
- Safe addition
- Sailors, coconuts and a monkey problem
- Same fringe
- Scope modifiers
- Search in paragraph's text
- Secure temporary file
- Self numbers
- Set of real numbers
- Sierpinski pentagon
- Simple database
- Simple turtle graphics
- Simulate input/Keyboard
- Simulate input/Mouse
- Smallest number k such that k+2^m is composite for all m less than k
- Snake
- Sokoban
- Solve a Hidato puzzle
- Solve a Holy Knight's tour
- Solve a Hopido puzzle
- Solve a Numbrix puzzle
- Sort an outline at every level
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Sorting algorithms/Comb sort
- Sorting algorithms/Counting sort
- Sorting algorithms/Heapsort
- Sorting algorithms/Pancake sort
- Sorting algorithms/Patience sort
- Sorting algorithms/Radix sort
- Sorting algorithms/Shell sort
- Sorting algorithms/Strand sort
- Special characters
- Special variables
- Speech synthesis
- Square form factorization
- Stable marriage problem
- State name puzzle
- Straddling checkerboard
- Strassen's algorithm
- Stream merge
- Subleq
- Subtractive generator
- Sudoku
- Suffixation of decimal numbers
- Sum to 100
- Superellipse
- Superpermutation minimisation
- Sutherland-Hodgman polygon clipping
- Synchronous concurrency

### T

- Table creation/Postal addresses
- Tarjan
- Taxicab numbers
- Terminal control/Clear the screen
- Terminal control/Coloured text
- Terminal control/Cursor movement
- Terminal control/Cursor positioning
- Terminal control/Dimensions
- Terminal control/Display an extended character
- Terminal control/Hiding the cursor
- Terminal control/Inverse video
- Terminal control/Positional read
- Terminal control/Preserve screen
- Terminal control/Unicode output
- Text processing/1
- The ISAAC Cipher
- The sieve of Sundaram
- Thiele's interpolation formula
- Tic-tac-toe
- Tonelli-Shanks algorithm
- Topic variable
- Topological sort
- Total circles area
- Tree datastructures
- Tree from nesting levels
- Truncate a file
- Twelve statements

### 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 Factor (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.

### A

### B

### C

- CLI-based maze-game
- Card shuffles
- Chebyshev coefficients
- Checksumcolor
- Chess player
- Code segment unload
- Collect and sort square numbers in ascending order from three lists
- Combinations with repetitions/Square digit chain
- Compiler/Simple file inclusion pre processor
- Compiler/Verifying syntax
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n)
- Continued fraction/Arithmetic/G(matrix ng, continued fraction n1, continued fraction n2)
- Count the coins/0-1
- Create an object/Native demonstration
- Create your own text control codes
- Curve that touches three points
- Cycles of a permutation

### D

### E

### F

### G

### I

### L

### M

### N

### P

### R

- Railway circuit
- Ramanujan primes
- Ramsey's theorem
- Range modifications
- 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/Run examples
- Rosetta Code/Tasks without examples
- Round-robin tournament schedule
- Run as a daemon or service

### S

- Safe and Sophie Germain primes
- Safe mode
- Sanitize user input
- Segmentation fault protection
- Selective file copy
- Self-hosting compiler
- Separate the house number from the street name
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Smallest enclosing circle problem
- Snake and Ladder
- Solve a Rubik's Cube
- Solve equations with substitution method
- Solve triangle solitare puzzle
- Solving coin problems
- Sort the letters of string in alphabetical order
- Sorting algorithms/Cycle sort
- Sorting algorithms/Tree sort on a linked list
- Special pythagorean triplet
- Spoof game
- Square root by hand
- Starting a web browser
- Subset sum problem
- Suffix tree
- Sunflower fractal

### T

- Table creation
- Tamagotchi emulator
- Terminal control/Restricted width positional input/No wrapping
- Terminal control/Restricted width positional input/With wrapping
- Tetris
- Text to HTML
- Three word location
- Time-based one-time password algorithm
- Topological sort/Extracted top item
- Transportation problem

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Factor, 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.

### No pages found.

### Other pages[edit]

These are other pages related to Factor 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 Factor was inappropriate for these tasks, or implementations of them would be unenlightening. Feel free to try your hand at them anyway.

## End of List[edit]

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