# Reports:Tasks not implemented in REXX

**Awareness**

If

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

## Contents

## Not implemented[edit]

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

### A

### B

### C

- Canny edge detector
- Catmull–Clark subdivision surface
- Chaocipher
- Chat server
- Checkpoint synchronization
- Chernick's Carmichael numbers
- Chinese zodiac
- Church numerals
- Color quantization
- Color wheel
- Colour pinstripe/Display
- Colour pinstripe/Printer
- Compare length of two strings
- Compiler/AST interpreter
- Compiler/code generator
- Compiler/lexical analyzer
- Compiler/syntax analyzer
- Compiler/virtual machine interpreter
- Concurrent computing
- Constrained genericity
- Create an object at a given address
- Cyclotomic polynomial

### D

### E

### F

### G

### H

### L

### M

- MD4
- Machine code
- Magic squares of singly even order
- Matrix-exponentiation operator
- Matrix chain multiplication
- Mayan calendar
- Maze solving
- Median filter
- Metered concurrency
- Minesweeper game
- Minimal steps down to 1
- Modular arithmetic
- Monads/List monad
- Monads/Writer monad
- Mouse position
- Multiple regression
- Mutex

### P

- P-Adic numbers, basic
- P-Adic square roots
- P-value correction
- Parallel brute force
- Parallel calculations
- Parametrized SQL statement
- Peaceful chess queen armies
- Peano curve
- Pentomino tiling
- Percentage difference between images
- Percolation/Bond percolation
- Percolation/Mean cluster density
- Percolation/Mean run density
- Percolation/Site percolation
- Peripheral drift illusion
- Pinstripe/Display
- Pinstripe/Printer
- Plasma effect
- Play recorded sounds
- Polymorphism
- Polyspiral
- Primes - allocate descendants to their ancestors
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/Middle-square method
- Pythagoras tree

### R

### S

- SHA-1
- SHA-256
- SHA-256 Merkle tree
- SOAP
- SQL-based authentication
- Send an unknown method call
- Sequence of primorial primes
- Set right-adjacent bits
- Sierpinski pentagon
- Sierpinski square curve
- Sierpinski triangle/Graphical
- Simple windowed application
- Simulate input/Mouse
- Singleton
- Snake
- Sockets
- Sokoban
- Sort an outline at every level
- Strassen's algorithm
- Sutherland-Hodgman polygon clipping
- Synchronous concurrency

### T

### U

### 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 REXX (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
- Camel case and snake case
- Checksumcolor
- Chess player
- Cipolla's algorithm
- Code Golf: Code Golf
- Combinations with repetitions/Square digit chain
- Compiler/Simple file inclusion pre processor
- Compiler/Verifying syntax
- Composite numbers k with no single digit factors whose factors are all substrings of k
- 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
- Cullen and Woodall numbers
- Curve that touches three points

### D

### E

### F

### I

### L

### M

### N

### P

### R

- Railway circuit
- Ramanujan primes
- Range modifications
- Raster bars
- Recursive descent parser generator
- Remote agent/Agent interface
- Remote agent/Agent logic
- Remote agent/Simulation
- Repunit primes
- Resistance calculator
- Resistance network calculator
- Robots
- Rodrigues’ rotation formula
- 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
- Ruth-Aaron numbers

### S

- Safe and Sophie Germain primes
- Sanitize user input
- Segmentation fault protection
- Self-hosting compiler
- Sierpinski curve
- Simple turtle graphics
- Simulated annealing
- Singly-linked list/Element removal
- Smallest enclosing circle problem
- Smallest multiple
- Smallest number k such that k+2^m is composite for all m less than k
- Solve a Rubik's Cube
- Solve equations with substitution method
- Solve triangle solitare puzzle
- Solving coin problems
- Sort primes from list to a list
- Sorting algorithms/Tree sort on a linked list
- Starting a web browser
- Suffix tree
- Sum of square and cube digits of an integer are primes
- Sum of two adjacent numbers are primes
- Summation of primes
- Sunflower fractal

### T

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in REXX, 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 REXX which require attention; with your knowledge and assistance, we can improve the quality of the site's content.

## Not Considered[edit]

These tasks are not generally counted toward "unimplemented", as somebody, somewhere, decided that REXX 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.