Examples Gallery

184+ example programs organized by category and difficulty

This gallery provides an overview of the Vais example programs in the examples/ directory. Examples range from basic "hello world" programs to advanced GPU, async, and self-hosting compiler demos.

Basics

Introductory programs demonstrating core syntax and features.

Example	Description	Key Concepts
hello.vais	Minimal program returning exit code	`F main()`
hello_world.vais	Print "Hello, World!"	`println`, strings
fib.vais	Fibonacci with self-recursion	`@` operator, recursion
math.vais	Arithmetic operations	Operators, expressions
math_test.vais	Math function tests	Function calls
putchar_var.vais	Character output	Variables, FFI
printf_test.vais	Formatted printing	`printf`, format strings

Featured: Fibonacci

# Self-recursion with @ operator
F fib(n:i64)->i64 = n<2 ? n : @(n-1) + @(n-2)

F main()->i64 = fib(10)   # Returns 55

Control Flow

If/else, loops, match, and branching patterns.

Example	Description	Key Concepts
control_flow.vais	Max, countdown, factorial	`I`/`E`, ternary `?:`
loop_break_test.vais	Loop with break	`L`, `B` (break)
loop_opt_test.vais	Loop optimization	`L`, `C` (continue)
match_test.vais	Pattern matching basics	`M` (match)
match_binding.vais	Match with variable binding	`M`, bindings
range_test.vais	Range iteration	`..` operator
range_comprehensive_test.vais	Complete range tests	Range types, inclusive
defer_test.vais	Deferred execution	`D` (defer)
defer_simple.vais	Simple defer	`D`

Featured: Pattern Matching

F describe(x: i64) -> i64 {
    M x {
        0 => 100,
        1 => 200,
        _ => 999
    }
}

Functions and Closures

Functions, lambdas, closures, and the pipe operator.

Example	Description	Key Concepts
pipe_operator.vais	Pipe chaining `\|>`	Pipe operator
closure_simple.vais	Simple closure	`\|x\| expr`
closure_test.vais	Closure capturing	Capture, closures
lambda_test.vais	Lambda expressions	Lambdas
inline_test.vais	Inline functions	`#[inline]`
tco_tail_call.vais	Tail call optimization	TCO, `@`
tco_stress.vais	TCO stress test	Deep recursion

Featured: Pipe Operator

F double(x: i64) -> i64 = x * 2
F add_ten(x: i64) -> i64 = x + 10

F main() -> i64 {
    result := 5 |> double |> add_ten   # 20
    result
}

Types and Structs

Struct definitions, methods, enums, and type features.

Example	Description	Key Concepts
enum_test.vais	Enum variants	`E` (enum), variants
enum_struct_variant_test.vais	Struct-like enum variants	`E`, struct variants
method_test.vais	Struct methods	`X` (impl), methods
destructuring.vais	Destructuring	Pattern destructuring
union_test.vais	Union types	`O` (union)
slice_test.vais	Slice operations	`&[T]`, fat pointers
type_infer_params.vais	Type inference	`:=` inference
linear_types_test.vais	Linear types	Ownership, move

Generics and Traits

Generic programming and trait-based polymorphism.

Example	Description	Key Concepts
generic_test.vais	Basic generics	`<T>`
generic_struct_test.vais	Generic structs	`S Pair<T>`
generic_bounds_test.vais	Trait bounds	`<T: Trait>`
generic_vec_test.vais	Generic Vec usage	`Vec<T>`
const_generic_test.vais	Const generics	`<const N: i64>`
trait_test.vais	Trait definition	`W` (trait)
trait_advanced_test.vais	Advanced traits	Default methods
trait_iter_test.vais	Iterator trait	`W Iterator`
gat_container.vais	GAT containers	GATs
gat_functor.vais	GAT functors	GATs
gat_iterator.vais	GAT iterators	GATs

Collections

Standard library collection types.

Example	Description	Key Concepts
simple_vec_test.vais	Vec basics	`Vec<T>`, push/pop
minimal_vec_test.vais	Minimal Vec	Allocation
simple_hashmap_test.vais	HashMap basics	`HashMap<K,V>`
map_literal.vais	Map literal syntax	Map literals
btreemap_test.vais	BTreeMap ordered map	`BTreeMap`
set_test.vais	Set operations	`Set<T>`
deque_test.vais	Double-ended queue	`Deque<T>`
priority_queue_test.vais	Priority queue	`PriorityQueue`
arrays.vais	Array operations	Arrays
iter_test.vais	Iterator patterns	`Iterator` trait

Error Handling

Option, Result, and error patterns.

Example	Description	Key Concepts
option_test.vais	Option basics	`Option<T>`
option_test2.vais	Option advanced	`Some`/`None`
option_test3.vais	Option chaining	`?` operator
result_test.vais	Result type	`Result<T,E>`
option_result_test.vais	Combined patterns	Option + Result
pattern_full_test.vais	Full pattern matching	Guards, nested
pattern_alias.vais	Pattern alias	`x @ pattern`

I/O and Networking

File, network, and HTTP operations.

Example	Description	Key Concepts
io_test.vais	I/O operations	`std/io`
file_test.vais	File read/write	`std/file`
http_test.vais	HTTP client	`std/http`
http_server_example.vais	HTTP server	`std/http_server`
websocket_example.vais	WebSocket	`std/websocket`
ipv6_test.vais	IPv6 networking	IPv6
ipv6_dual_stack.vais	Dual-stack networking	IPv4/v6

Data Formats

JSON, TOML, templates, and serialization.

Example	Description	Key Concepts
json_test.vais	JSON builder API	`std/json`
template_example.vais	String templates	`std/template`
compress_example.vais	Data compression	`std/compress`
crc32.vais	CRC32 checksums	`std/crc32`
pilot_json2toml.vais	JSON to TOML converter	JSON, TOML

Async and Concurrency

Async operations, threads, and synchronization.

Example	Description	Key Concepts
async_test.vais	Async basics	`A` (async), `Y` (await)
async_reactor_test.vais	Async reactor	Event loop
spawn_test.vais	Task spawning	`spawn`
thread_test.vais	Thread creation	`std/thread`
sync_test.vais	Mutex/lock	`std/sync`
concurrency_stress.vais	Concurrency stress	Thread safety
lazy_test.vais	Lazy evaluation	`lazy`/`force`
lazy_simple.vais	Simple lazy	Thunks

Memory and System

Memory management, GC, and system operations.

Example	Description	Key Concepts
memory_test.vais	Memory operations	`malloc`/`free`
malloc_test.vais	Manual allocation	Pointers
rc_test.vais	Reference counting	`Rc<T>`
gc_test.vais	Garbage collector	`std/gc`
gc_vec_test.vais	GC with Vec	GC + collections
gc_simple_demo.vais	GC demo	GC basics
lifetime_test.vais	Lifetime checking	Borrow checker
runtime_test.vais	Runtime system	`std/runtime`

Databases

Database integration examples.

Example	Description	Key Concepts
sqlite_example.vais	SQLite operations	`std/sqlite`
postgres_example.vais	PostgreSQL client	`std/postgres`
orm_example.vais	ORM usage	`std/orm`

WebAssembly

WASM target and interop examples.

Example	Description	Key Concepts
wasm_calculator.vais	WASM calculator	`#[wasm_export]`
wasm_interop.vais	JS/WASM interop	`#[wasm_import]`
wasm_api_client.vais	WASM API client	Fetch, DOM
wasm_todo_app.vais	WASM todo app	Full app
js_target.vais	JavaScript target	`--target js`
js_target_advanced.vais	Advanced JS output	ESM modules

GPU

GPU computing examples.

Example	Description	Key Concepts
gpu_vector_add.vais	GPU vector addition	`std/gpu`, kernels
simd_test.vais	SIMD operations	`std/simd`
simd_distance.vais	SIMD distance calc	Vectorization

Macros and Metaprogramming

Macro system and compile-time features.

Example	Description	Key Concepts
macro_test.vais	Declarative macros	`macro!`
comptime_test.vais	Compile-time eval	`comptime`
comptime_simple.vais	Simple comptime	Const evaluation
contract_test.vais	Design by contract	Pre/postconditions

Benchmarks

Performance measurement programs.

Example	Description	Key Concepts
bench_fibonacci.vais	Fibonacci benchmark	Recursive performance
bench_compute.vais	Compute benchmark	Arithmetic performance
bench_sorting.vais	Sorting benchmark	Algorithm performance
bench_matrix.vais	Matrix operations	Dense computation
bench_tree.vais	Tree benchmark	Data structure perf
stress_memory.vais	Memory stress test	Allocation patterns
stress_fd.vais	File descriptor stress	I/O limits

Self-Hosting

Self-hosting compiler components in Vais.

Example	Description	Key Concepts
selfhost_arith.vais	Arithmetic codegen	Bootstrap
selfhost_loop.vais	Loop codegen	Bootstrap
selfhost_cond.vais	Conditional codegen	Bootstrap
selfhost_nested.vais	Nested calls codegen	Bootstrap
selfhost_bitwise.vais	Bitwise ops codegen	Bootstrap

Pilot Projects

Complete application examples.

Example	Description	Key Concepts
pilot_rest_api.vais	REST API server	HTTP, routing
pilot_json2toml.vais	JSON-to-TOML converter	Data conversion
tutorial_wc.vais	Word count tool	CLI tutorial
tutorial_pipeline.vais	Data pipeline	ETL pattern

Running Examples

# Compile and run
cargo run --bin vaisc -- examples/fib.vais

# Compile to JavaScript
cargo run --bin vaisc -- --target js examples/js_target.vais

# Compile to WASM
cargo run --bin vaisc -- --target wasm32-unknown-unknown examples/wasm_calculator.vais

Vais Programming Language