4,244
students have developed their Common Lisp skills on Exercism.

Students
4,244
Submissions
63,938
Mentoring Discussions
2,240

The Common Lisp track needs attention ⚠️

Building

Build

Use your knowledge to build the Common Lisp track itself

Create the Common Lisp syllabus

Learn More

Help create the track syllabus: is a set of concepts and learning exercises put together to teach foundational elements of the programming language.

Next goal: Create a complete syllabus with at least 30 concepts. Find out more.

Usage statistics

27 concepts being taught
Co
Comments
769 learnt
Co
Cons
769 learnt
Ex
Expressions
769 learnt
Sy
Symbols
769 learnt
Eq
Equality
122 learnt
Ar
Arithmetic
576 learnt
Fl
Floating Point Numbers
576 learnt
In
Integers
576 learnt
Li
Lists
440 learnt
Co
Conditionals
327 learnt
Tr
Truthy And Falsy
327 learnt
Fu
Functions
306 learnt
Ke
Keyword Parameters
172 learnt
La
Lambda List
172 learnt
Op
Optional Parameters
172 learnt
Re
Rest-Parameters
172 learnt
St
Strings
180 learnt
Ch
Characters
154 learnt
Ar
Arrays
153 learnt
Ve
Vectors
153 learnt
Ha
Hash Tables
148 learnt
Fi
Filtering
137 learnt
Ma
Mapping
137 learnt
Da
Date and Time
154 learnt
Mu
Multiple Values
154 learnt
Re
Reducing
95 learnt
Fo
Format - Basics
91 learnt
15 active learning exercises
Started
Attempts
Completions
Mentoring requests
Sorting Socks and Sexprs Sorting Socks and Sexprs
1,191
6,844 (avg. 5.7)
769 (64.6%)
5 (0.4%)
The Key to Comparison The Key to Comparison
129
776 (avg. 6.0)
122 (94.6%)
1 (0.8%)
Pizza Pi Pizza Pi
644
6,885 (avg. 10.7)
576 (89.4%)
10 (1.6%)
Leslie's Lengthy Lists Leslie's Lengthy Lists
474
3,874 (avg. 8.2)
440 (92.8%)
7 (1.5%)
Pal Picker Pal Picker
350
3,698 (avg. 10.6)
327 (93.4%)
6 (1.7%)
Lilly's Lasagna Lilly's Lasagna
315
1,819 (avg. 5.8)
306 (97.1%)
2 (0.6%)
Lilly's Lasagna Leftovers Lilly's Lasagna Leftovers
194
2,334 (avg. 12.0)
172 (88.7%)
4 (2.1%)
Log Levels Log Levels
193
1,370 (avg. 7.1)
180 (93.3%)
3 (1.6%)
Character Study Character Study
161
862 (avg. 5.4)
154 (95.7%)
1 (0.6%)
Larry's Winning Checker Larry's Winning Checker
172
2,360 (avg. 13.7)
153 (89.0%)
4 (2.3%)
High Scores High Scores
157
1,073 (avg. 6.8)
148 (94.3%)
1 (0.6%)
Lucy's Magnificent Mapper Lucy's Magnificent Mapper
141
568 (avg. 4.0)
137 (97.2%)
2 (1.4%)
Gigasecond Anniversary Gigasecond Anniversary
177
1,286 (avg. 7.3)
154 (87.0%)
1 (0.6%)
Logan's Numeric Partition Logan's Numeric Partition
111
1,292 (avg. 11.6)
95 (85.6%)
2 (1.8%)
Reporting for Duty Reporting for Duty
96
613 (avg. 6.4)
91 (94.8%)
1 (1.0%)

Build Test Runners

Learn More

Create Test Runners that have the single responsibility of taking a solution, running all tests and returning a standardized output.

Next goal: Get Test Runners to Version 3. Common Lisp is currently utilising a Version 2 Test Runner. Find out more.

Usage statistics

Total Test Runner Runs
56,934
Test Run Pass Rate
21.9% (12453)
Test Run Fail Rate
67.6% (38472)
Test Run Error Rate
10.6% (6009)

Build Analyzers

Learn More

Build an Analyzer for Common Lisp: Exercism's analyzers automatically assess student's submissions and provide mentor-style commentary.

Usage statistics

Total Analyzer Runs
10,277
Total Analysis Comments Made
0
Feedback Given Frequency
0.0%

Build Representers

Learn More

Build a Representer: a bit of code that has the single responsibility of taking a solution and returning a normalized representation of it.

Usage statistics

Total Representer Runs
10,276
Total Representation Comments Made
1,584
Feedback Given Frequency
15.4%

Create Practice Exercises

Learn More

Practice Exercises are exercises designed to allow students to solve an arbitrary problem, with the aim of them making use of the concepts they have learned so far.

Next goal: Implement 121 practice exercises. Find out more.

Usage statistics

68 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
2,672
3,503 (avg. 1.3)
2,098 (78.5%)
8 (0.3%)
Two Fer Two Fer
500
1,151 (avg. 2.3)
395 (79.0%)
241 (48.2%)
Hamming Hamming
662
1,885 (avg. 2.8)
554 (83.7%)
362 (54.7%)
RNA Transcription RNA Transcription
385
892 (avg. 2.3)
334 (86.8%)
184 (47.8%)
Leap Leap
520
1,259 (avg. 2.4)
485 (93.3%)
242 (46.5%)
Anagram Anagram
253
794 (avg. 3.1)
212 (83.8%)
113 (44.7%)
Beer Song Beer Song
227
1,073 (avg. 4.7)
190 (83.7%)
100 (44.1%)
Roman Numerals Roman Numerals
217
602 (avg. 2.8)
188 (86.6%)
89 (41.0%)
Word Count Word Count
206
700 (avg. 3.4)
161 (78.2%)
92 (44.7%)
Bob Bob
254
731 (avg. 2.9)
207 (81.5%)
137 (53.9%)
Twelve Days Twelve Days
82
290 (avg. 3.5)
68 (82.9%)
8 (9.8%)
Acronym Acronym
237
468 (avg. 2.0)
166 (70.0%)
47 (19.8%)
All Your Base All Your Base
329
1,629 (avg. 5.0)
140 (42.6%)
20 (6.1%)
Allergies Allergies
96
362 (avg. 3.8)
77 (80.2%)
11 (11.5%)
Armstrong Numbers Armstrong Numbers
92
212 (avg. 2.3)
77 (83.7%)
3 (3.3%)
Binary Search Binary Search
65
330 (avg. 5.1)
54 (83.1%)
4 (6.2%)
Collatz Conjecture Collatz Conjecture
217
900 (avg. 4.1)
172 (79.3%)
29 (13.4%)
Difference of Squares Difference of Squares
193
633 (avg. 3.3)
162 (83.9%)
12 (6.2%)
ETL ETL
129
326 (avg. 2.5)
97 (75.2%)
17 (13.2%)
Grains Grains
314
791 (avg. 2.5)
292 (93.0%)
55 (17.5%)
Isogram Isogram
94
229 (avg. 2.4)
80 (85.1%)
14 (14.9%)
Nucleotide Count Nucleotide Count
116
290 (avg. 2.5)
92 (79.3%)
19 (16.4%)
Pascal's Triangle Pascal's Triangle
120
541 (avg. 4.5)
83 (69.2%)
11 (9.2%)
Perfect Numbers Perfect Numbers
108
363 (avg. 3.4)
89 (82.4%)
9 (8.3%)
Raindrops Raindrops
147
304 (avg. 2.1)
120 (81.6%)
28 (19.0%)
Scrabble Score Scrabble Score
89
164 (avg. 1.8)
75 (84.3%)
8 (9.0%)
Sieve Sieve
104
314 (avg. 3.0)
84 (80.8%)
27 (26.0%)
Space Age Space Age
162
488 (avg. 3.0)
134 (82.7%)
23 (14.2%)
Strain Strain
96
155 (avg. 1.6)
83 (86.5%)
11 (11.5%)
Sublist Sublist
241
901 (avg. 3.7)
143 (59.3%)
30 (12.4%)
Triangle Triangle
103
299 (avg. 2.9)
82 (79.6%)
14 (13.6%)
Atbash Cipher Atbash Cipher
80
200 (avg. 2.5)
64 (80.0%)
4 (5.0%)
Grade School Grade School
123
371 (avg. 3.0)
90 (73.2%)
22 (17.9%)
Phone Number Phone Number
121
240 (avg. 2.0)
101 (83.5%)
20 (16.5%)
Prime Factors Prime Factors
90
183 (avg. 2.0)
68 (75.6%)
12 (13.3%)
Robot Name Robot Name
151
299 (avg. 2.0)
128 (84.8%)
58 (38.4%)
Robot Simulator Robot Simulator
63
173 (avg. 2.7)
46 (73.0%)
4 (6.3%)
Crypto Square Crypto Square
73
286 (avg. 3.9)
54 (74.0%)
8 (11.0%)
Meetup Meetup
77
205 (avg. 2.7)
54 (70.1%)
8 (10.4%)
Luhn Luhn
174
385 (avg. 2.2)
124 (71.3%)
23 (13.2%)
Book Store Book Store
23
202 (avg. 8.8)
16 (69.6%)
2 (8.7%)
ISBN Verifier ISBN Verifier
24
101 (avg. 4.2)
23 (95.8%)
0 (0.0%)
Sum of Multiples Sum of Multiples
40
121 (avg. 3.0)
32 (80.0%)
1 (2.5%)
Matching Brackets Matching Brackets
23
107 (avg. 4.7)
22 (95.7%)
0 (0.0%)
Run-Length Encoding Run-Length Encoding
19
161 (avg. 8.5)
16 (84.2%)
1 (5.3%)
Largest Series Product Largest Series Product
17
85 (avg. 5.0)
16 (94.1%)
0 (0.0%)
Queen Attack Queen Attack
23
78 (avg. 3.4)
21 (91.3%)
0 (0.0%)
Nth Prime Nth Prime
37
120 (avg. 3.2)
28 (75.7%)
0 (0.0%)
Knapsack Knapsack
15
50 (avg. 3.3)
14 (93.3%)
0 (0.0%)
Rail Fence Cipher Rail Fence Cipher
14
126 (avg. 9.0)
12 (85.7%)
0 (0.0%)
Pig Latin Pig Latin
13
123 (avg. 9.5)
11 (84.6%)
0 (0.0%)
Protein Translation Protein Translation
18
121 (avg. 6.7)
14 (77.8%)
0 (0.0%)
Saddle Points Saddle Points
15
73 (avg. 4.9)
12 (80.0%)
0 (0.0%)
Matrix Matrix
12
93 (avg. 7.8)
11 (91.7%)
0 (0.0%)
Palindrome Products Palindrome Products
16
159 (avg. 9.9)
13 (81.3%)
0 (0.0%)
Pythagorean Triplet Pythagorean Triplet
20
104 (avg. 5.2)
15 (75.0%)
1 (5.0%)
Affine Cipher Affine Cipher
13
155 (avg. 11.9)
12 (92.3%)
0 (0.0%)
Say Say
15
28 (avg. 1.9)
13 (86.7%)
0 (0.0%)
Two Bucket Two Bucket
15
157 (avg. 10.5)
10 (66.7%)
2 (13.3%)
Flatten Array Flatten Array
17
41 (avg. 2.4)
17 (100.0%)
0 (0.0%)
Spiral Matrix Spiral Matrix
13
56 (avg. 4.3)
12 (92.3%)
0 (0.0%)
Diamond Diamond
12
110 (avg. 9.2)
11 (91.7%)
0 (0.0%)
Rotational Cipher Rotational Cipher
19
47 (avg. 2.5)
16 (84.2%)
0 (0.0%)
Pangram Pangram
18
67 (avg. 3.7)
17 (94.4%)
0 (0.0%)
Secret Handshake Secret Handshake
23
60 (avg. 2.6)
20 (87.0%)
0 (0.0%)
Darts Darts
49
208 (avg. 4.2)
45 (91.8%)
0 (0.0%)
Proverb Proverb
15
70 (avg. 4.7)
15 (100.0%)
0 (0.0%)
Food Chain Food Chain
13
91 (avg. 7.0)
10 (76.9%)
0 (0.0%)
3 deprecated practice exercises
Started
Attempts
Completions
Mentoring requests
Binary Binary
71
137 (avg. 1.9)
55 (77.5%)
12 (16.9%)
Gigasecond Gigasecond
176
227 (avg. 1.3)
147 (83.5%)
40 (22.7%)
Trinary Trinary
59
85 (avg. 1.4)
47 (79.7%)
8 (13.6%)
53 unimplemented practice exercises
Alphametics Alphametics
Binary Search Tree Binary Search Tree
Bottle Song Bottle Song
Bowling Bowling
Change Change
Circular Buffer Circular Buffer
Clock Clock
Complex Numbers Complex Numbers
Connect Connect
Custom Set Custom Set
D&D Character D&D Character
DOT DSL DOT DSL
Dominoes Dominoes
Error Handling Error Handling
Forth Forth
Go Counting Go Counting
Grep Grep
Hangman Hangman
High Scores High Scores
House House
Killer Sudoku Helper Killer Sudoku Helper
Kindergarten Garden Kindergarten Garden
Ledger Ledger
Markdown Markdown
Micro Blog Micro Blog
Minesweeper Minesweeper
OCR Numbers OCR Numbers
POV POV
PaaS I/O PaaS I/O
Poker Poker
REST API REST API
Rational Numbers Rational Numbers
React React
Rectangles Rectangles
Resistor Color Resistor Color
Resistor Color Duo Resistor Color Duo
Resistor Color Trio Resistor Color Trio
SGF Parsing SGF Parsing
Satellite Satellite
Scale Generator Scale Generator
Series Series
Simple Cipher Simple Cipher
Square Root Square Root
State of Tic-Tac-Toe State of Tic-Tac-Toe
Tournament Tournament
Transpose Transpose
Tree Building Tree Building
Variable Length Quantity Variable Length Quantity
Word Search Word Search
Wordy Wordy
Yacht Yacht
Zebra Puzzle Zebra Puzzle
Zipper Zipper
8 foregone practice exercises
Accumulate Accumulate
Bank Account Bank Account
Lens Person Lens Person
Linked List Linked List
List Ops List Ops
Parallel Letter Frequency Parallel Letter Frequency
Reverse String Reverse String
Simple Linked List Simple Linked List