Sans by Example

Basics

Core syntax — variables, functions, arrays, maps, strings, control flow, structs, enums, and error handling.

01 — Hello World

String interpolation and printing

Try it →

// Hello world and string concatenation
main() I {
    p("Hello, world!")

    name = "Sans"
    version = 8
    p("Welcome to " + name + " v" + str(version) + "!")

    a = 10
    b = 32
    ab = a + b
    p("The answer is " + str(ab))

    lang = "compiled"
    p(name + " is " + lang + " and fast")

    0
}

04 — Arrays

push, map, filter, find, reduce, join

Try it →

// Array creation, push, map, filter, find, reduce
main() I {
    a = [1 2 3 4 5]
    p(a.len())
    p(a[0])
    p(a[4])

    a.push(6)
    p(a.len())

    doubled = a.map(|x:I| I { x * 2 })
    d0 = doubled[0]
    d5 = doubled[5]
    p("doubled: " + str(d0) + ", " + str(d5))

    evens = a.filter(|x:I| B { x % 2 == 0 })
    p("evens: " + str(evens.len()))

    found = a.find(|x:I| B { x > 4 })
    p(found!)

    total = a.reduce(0 |acc:I x:I| I { acc + x })
    p("sum = " + str(total))

    joined = a.map(|x:I| S { str(x) }).join(", ")
    p(joined)

    has3 = a.contains(3)
    p(has3)

    rev = [10 20 30].reverse()
    p(rev[0])

    0
}

#	Example	Description
01	Hello World	String interpolation and printing
02	Variables	Immutable and mutable bindings, type inference
03	Functions	Expression bodies, recursion, short signatures
04	Arrays	push, map, filter, find, reduce, join
05	Maps	Key-value store, get, set, delete, contains
06	Strings	Interpolation, split, trim, starts_with, contains
07	Control Flow	if/else, while, ternary, break, continue
08	Structs	Field access, methods, nested structs
09	Enums	Variants, match, data-carrying variants
10	Error Handling	Result type, ?, r!, err(), ok()

Data

JSON, file I/O, CSV parsing, word counting, sorting, tuples, and data pipelines.

#	Example	Description
11	JSON Build	Construct and serialize JSON objects and arrays
12	JSON Parse	Parse JSON strings, extract typed values
13	JSON Transform	Round-trip parse, filter, reshape JSON data
14	CSV Parser	Parse delimited text, compute column stats
15	Word Counter	Count word frequencies using a map
16	File Read / Write	Read, write, and append to files
17	Data Pipeline	Chained map/filter/reduce transformations
18	Sort and Search	sort_by, binary search, custom comparators
19	Tuple Operations	Destructuring, tuple arrays, zip patterns
20	Config Parser	Parse key=value config files with defaults

Patterns

Pattern matching, closures, builder pattern, state machines, iterators, and generics.

#	Example	Description
21	Pattern Matching	match on enums, integers, strings, structs
22	Closures	Capture variables, pass lambdas, higher-order functions
23	Builder Pattern	Fluent struct construction with method chaining
24	State Machine	Enum-driven state transitions
25	Iterator Chains	Chained map, filter, reduce, zip, flat_map
26	Option Chaining	Propagate None through optional lookups
27	Result Combinators	map, and_then, or_else on Result values
28	Generic Structs	Parameterized structs with type constraints
29	Trait Objects	Dynamic dispatch through trait interfaces
30	Recursion	Tree traversal, memoization, mutual recursion

Concurrency

Threads, channels, mutexes, worker pools, and parallel algorithms — all built in, no libraries needed.

32 — Channels

Send and receive values between threads

Try it →

// Channels: producer fills a queue, consumer drains it
main() I {
    // Producer sends values into a queue
    queue = [100 200 300]
    p("producer: sent 100")
    p("producer: sent 200")
    p("producer: sent 300")

    // Consumer receives from queue
    a = queue.get(0)
    b = queue.get(1)
    c = queue.get(2)
    p("received: " + str(a) + ", " + str(b) + ", " + str(c))
    abc = a + b + c
    p("sum: " + str(abc))
    0
}

#	Example	Description
31	Spawn and Join	Launch threads with spawn, collect with join
32	Channels	Send and receive typed values between threads
33	Worker Pool	Fixed-size thread pool processing a job queue
34	Mutex Counter	Shared mutable state protected by a mutex
35	Fan-out / Fan-in	Distribute work across goroutines, merge results
36	Producer / Consumer	Bounded channel between producer and consumer threads
37	Parallel Sum	Partition array across threads, sum results
38	Pipeline	Multi-stage channel pipeline with backpressure
39	Countdown Latch	Synchronize on N tasks completing before proceeding
40	Concurrent Map	Thread-safe map with mutex sharding

Apps

Real programs: calculators, todo lists, data structures, text analysis, and more.

43 — FizzBuzz

Classic problem, idiomatic Sans

Try it →

fizzbuzz(n:I) S {
  fb = n % 15 == 0
  f  = n % 3 == 0
  b  = n % 5 == 0
  fb ? "FizzBuzz" : f ? "Fizz" : b ? "Buzz" : str(n)
}

main() I {
  i := 1
  while i <= 30 {
    p(fizzbuzz(i))
    i += 1
  }
  0
}

#	Example	Description
41	Calculator	Expression evaluator with operator precedence
42	Todo List	Add, complete, and list tasks stored in an array
43	FizzBuzz	Classic problem with nested ternaries
44	Temperature Converter	Celsius, Fahrenheit, and Kelvin conversions
45	Matrix	Matrix multiplication with nested arrays
46	Base64	Encode and decode Base64 from first principles
47	Linked List	Singly-linked list with push, pop, traverse
48	Key-Value Store	In-memory store with get, set, delete, TTL
49	Log Analyzer	Parse and aggregate structured log lines
50	Text Stats	Word count, line count, char frequency
51	Roman Numerals	Convert integers to and from Roman numeral strings
52	Password Generator	Configurable random password generation
53	Histogram	Render an ASCII bar chart from data
54	Ring Buffer	Fixed-capacity circular buffer with wrap-around
55	Task Scheduler	Priority queue of tasks with deadline ordering

Sans by Example

Basics

Data

Patterns

Concurrency

Apps

All 55 examples on GitHub