# Reports:Tasks not implemented in Tcl

**Awareness**

If

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

## Contents

## Not implemented[edit]

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

### 2

### A

### B

### C

- Calkin-Wilf sequence
- Canonicalize CIDR
- Cantor set
- Chaocipher
- Chaos game
- Chernick's Carmichael numbers
- Cheryl's birthday
- Chowla numbers
- Church numerals
- Circular primes
- Cistercian numerals
- Color wheel
- Colorful numbers
- Commatizing numbers
- Compare length of two strings
- 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
- Consecutive primes with ascending or descending differences
- Cuban primes
- Cullen and Woodall numbers
- Curzon numbers
- Cyclops numbers
- Cyclotomic polynomial

### D

### E

- EKG sequence convergence
- Earliest difference between prime gaps
- Eban numbers
- Eertree
- Egyptian division
- Elliptic Curve Digital Signature Algorithm
- Equal prime and composite sums
- Erdös-Selfridge categorization of primes
- Esthetic numbers
- Euler's constant 0.5772...
- Execute Computer/Zero
- Exponentiation with infix operators in (or operating on) the base

### F

- Faces from a mesh
- Factorial base numbers indexing permutations of a collection
- Factorions
- Fairshare between two and more
- Faulhaber's formula
- Faulhaber's triangle
- Feigenbaum constant calculation
- Find Chess960 starting position identifier
- Find if a point is within a triangle
- Find the intersection of a line with a plane
- Find the intersection of two lines
- First perfect square in base n with n unique digits
- First power of 2 that has leading decimal digits of 12
- Fivenum
- Fortunate numbers
- Four is magic
- Four is the number of letters in the ...
- Fraction reduction
- French Republican calendar
- Functional coverage tree

### I

### L

- Largest number divisible by its digits
- Largest proper divisor of n
- Latin Squares in reduced form
- Latin Squares in reduced form/Randomizing using Jacobson and Matthews’ Technique
- Law of cosines - triples
- Legendre prime counting function
- Leonardo numbers
- List rooted trees
- Long primes
- Longest common substring
- Loops/With multiple ranges
- Loops/Wrong ranges

### M

- Magic constant
- Magic squares of doubly even order
- Magic squares of singly even order
- Magnanimous numbers
- Mastermind
- Matrix chain multiplication
- Matrix digital rain
- Mayan calendar
- Mayan numerals
- McNuggets problem
- Merge and aggregate datasets
- Mertens function
- Metallic ratios
- Mian-Chowla sequence
- Mind boggling card trick
- Minimal steps down to 1
- Minimum multiple of m where digital sum equals m
- Minkowski question-mark function
- Modified random distribution
- Monads/List monad
- Monads/Maybe monad
- Monads/Writer monad
- Motzkin numbers
- Multi-base primes
- Munchausen numbers
- Möbius function

### N

### P

- P-Adic numbers, basic
- P-Adic square roots
- P-value correction
- Padovan n-step number sequences
- Padovan sequence
- Palindrome dates
- Palindromic gapful numbers
- Pancake numbers
- Parallel brute force
- Particle fountain
- Partition an integer x into n primes
- Partition function P
- Password generator
- Pathological floating point problems
- Peaceful chess queen armies
- Peano curve
- Pell's equation
- Pell numbers
- Pentomino tiling
- Periodic table
- Peripheral drift illusion
- Pierpont primes
- Pisano period
- Plasma effect
- Polyspiral
- Primality by Wilson's theorem
- Prime conspiracy
- Prime triangle
- Primes - allocate descendants to their ancestors
- Primorial numbers
- Pseudo-random numbers/Combined recursive generator MRG32k3a
- Pseudo-random numbers/Middle-square method
- Pseudo-random numbers/PCG32
- Pseudo-random numbers/Splitmix64
- Pseudo-random numbers/Xorshift star
- Pythagoras tree
- Pythagorean quadruples

### R

- RPG attributes generator
- Ramanujan's constant
- Ramanujan primes/twins
- Ramer-Douglas-Peucker line simplification
- Random Latin squares
- Random sentence from book
- Range consolidation
- Rare numbers
- Recaman's sequence
- Repunit primes
- Rhonda numbers
- Rosetta Code/Rank languages by number of users
- Ruth-Aaron numbers

### S

- SHA-256 Merkle tree
- Safe primes and unsafe primes
- Search in paragraph's text
- Selectively replace multiple instances of a character within a string
- Self numbers
- Sequence: nth number with exactly n divisors
- Sequence: smallest number greater than previous term with exactly n divisors
- Sequence of primorial primes
- Set right-adjacent bits
- Sexy primes
- Shoelace formula for polygonal area
- Sierpinski arrowhead curve
- Sierpinski pentagon
- Sierpinski square curve
- Simple turtle graphics
- Sleeping Beauty problem
- Smallest number k such that k+2^m is composite for all m less than k
- Smarandache prime-digital sequence
- Snake
- Sort an outline at every level
- Sorting Algorithms/Circle Sort
- Sorting algorithms/Cocktail sort with shifting bounds
- Spelling of ordinal numbers
- Spinning rod animation/Text
- Square form factorization
- Strassen's algorithm
- Strong and weak primes
- Successive prime differences
- Sudan function
- Suffixation of decimal numbers
- Sum and product puzzle
- Sum of elements below main diagonal of matrix
- Summarize primes
- Super-d numbers
- Superellipse
- Superpermutation minimisation
- Sylvester's sequence

### T

### U

### 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 Tcl (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
- Change e letters to i in words
- Changeable words
- Chebyshev coefficients
- Checksumcolor
- Chemical calculator
- Chess player
- Cipolla's algorithm
- Code Golf: Code Golf
- Collect and sort square numbers in ascending order from three lists
- Combinations with repetitions/Square digit chain
- Common list elements
- Common sorted list
- Compiler/Preprocessor
- Compiler/Simple file inclusion pre processor
- Compiler/Verifying syntax
- Concatenate two primes is also prime
- Conjugate a Latin verb
- Coprime triplets
- Coprimes
- Count how many vowels and consonants occur in a string
- Count the coins/0-1
- Cousin primes
- Create an executable for a program in an interpreted language
- Create your own text control codes
- Cross compilation
- Cubic special primes
- Curve that touches three points
- Cycle detection
- Cycles of a permutation

### D

- Data Encryption Standard
- Dating agency
- Day of the week of Christmas and New Year
- Days between dates
- Digit fifth powers
- Diophantine linear system solving
- Discrete Fourier transform
- Distinct palindromes within decimal numbers
- Distinct power numbers
- Distribution of 0 digits in factorial series
- Divide a rectangle into a number of unequal triangles
- Doomsday rule
- Doubly-linked list/Element removal
- Draw pixel 2

### E

### F

- Factorial primes
- Fibonacci heap
- Fibonacci matrix-exponentiation
- Find adjacent primes which differ by a square integer
- Find first missing positive
- Find minimum number of coins that make a given value
- Find prime n such that reversed n is also prime
- Find prime numbers of the form n*n*n+2
- Find square difference
- Find squares n where n+1 is prime
- Find words which contain the most consonants
- Find words which contains all the vowels
- Find words which contains more than 3 e vowels
- Find words whose first and last three letters are equal
- Find words with alternating vowels and consonants
- First 9 prime Fibonacci number
- Four sides of square
- Free polyominoes enumeration
- Frobenius numbers

### G

### I

### L

- Largest difference between adjacent primes
- Largest five adjacent number
- Largest palindrome product
- Largest prime factor
- Largest product in a grid
- Last list item
- Launch rocket with countdown and acceleration in stdout
- Length of an arc between two angles
- Line circle intersection
- Logistic curve fitting in epidemiology
- Long stairs
- Longest common suffix
- Longest palindromic substrings
- Longest substrings without repeating characters

### M

- Marching squares
- Markov chain text generator
- Matrix with two diagonals
- Maximum difference between adjacent elements of list
- Mersenne primes
- Minimum number of cells after, before, above and below NxN squares
- Minimum numbers of three lists
- Minimum primes
- Morpion solitaire
- Mosaic matrix
- Multidimensional Newton-Raphson method
- Multiton

### N

- N-queens minimum and knights and bishops
- Native shebang
- Neighbour primes
- Next special primes
- Nice primes
- Nimber arithmetic
- Number triplets game
- Numbers divisible by their individual digits, but not by the product of their digits.
- Numbers in base-16 representation that cannot be written with decimal digits
- Numbers in base 10 that are palindromic in bases 2, 4, and 16
- Numbers which binary and ternary digit sum are prime
- Numbers whose count of divisors is prime
- Numbers with prime digits whose sum is 13
- Numbers with same digit set in base 10 and base 16
- Numeric separator syntax
- Numerical integration/Adaptive Simpson's method

### O

### P

- Palindromic primes
- Palindromic primes in base 16
- Pan base non-primes
- Pandigital prime
- Particle swarm optimization
- Penrose tiling
- Perceptron
- Permutations with some identical elements
- Permuted multiples
- Piprimes
- Polynomial derivative
- Positive decimal integers with the digit 1 occurring exactly twice
- Powerful numbers
- Practical numbers
- Price list behind API
- Prime numbers p for which the sum of primes less than or equal to p is prime
- Prime numbers which contain 123
- Prime triplets
- Prime words
- Primes which contain only one odd digit
- Primes whose first and last number is 3
- Primes with digits in nondecreasing order
- Print debugging statement
- Print itself
- Product of divisors
- Pseudorandom number generator image

### R

- Railway circuit
- Ramanujan primes
- Range modifications
- Raster bars
- Readline interface
- Recursive descent parser generator
- Red black tree sort
- Remove vowels from a string
- Resistance calculator
- Resistance network calculator
- Reverse the order of lines in a text file while preserving the contents of each line
- Robots
- Rodrigues’ rotation formula
- Rosetta Code/List authors of task descriptions
- Rosetta Code/Tasks without examples
- Round-robin tournament schedule

### S

- Safe and Sophie Germain primes
- Safe mode
- Sanitize user input
- Sattolo cycle
- Segmentation fault protection
- Selective file copy
- Self-hosting compiler
- Shift list elements to left by 3
- Show the (decimal) value of a number of 1s appended with a 3, then squared
- Sierpinski curve
- Simulated annealing
- Sine wave
- Singly-linked list/Element removal
- Smallest enclosing circle problem
- Smallest multiple
- Smallest numbers
- Smallest power of 6 whose decimal expansion contains n
- Smallest square that begins with n
- Snake and ladder
- Solve a Rubik's cube
- Solve equations with substitution method
- Solve hanging lantern problem
- Solve triangle solitare puzzle
- Solving coin problems
- Sort primes from list to a list
- Sort the letters of string in alphabetical order
- Sorting algorithms/Tree sort on a linked list
- Special divisors
- Special factorials
- Special neighbor primes
- Special pythagorean triplet
- Spoof game
- Square root by hand
- Steady squares
- Strange numbers
- Strange plus numbers
- Strange unique prime triplets
- Substring primes
- Suffix tree
- Sum data type
- Sum of divisors
- Sum of first n cubes
- Sum of primes in odd positions is prime
- Sum of square and cube digits of an integer are primes
- Sum of the digits of n is substring of n
- Sum of two adjacent numbers are primes
- Summation of primes
- Sunflower fractal

### T

- Tamagotchi emulator
- Terminal control/Restricted width positional input/No wrapping
- Terminal control/Restricted width positional input/With wrapping
- Tetris
- Text completion
- Three word location
- Transliterate English text using the Greek alphabet
- Transportation problem
- Triplet of three numbers
- Tropical algebra overloading
- Two identical strings
- Two sum
- Type detection

### U

### W

## Requiring Attention[edit]

### Examples[edit]

These tasks have implementations in Tcl, 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.

### A

### D

### M

### P

### Other pages[edit]

These are other pages related to Tcl 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 Tcl 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.