-- patterns.ail - Comprehensive pattern matching examples

-- Demonstrates all pattern types supported in AILANG

-- =======================

-- TUPLE PATTERNS

-- =======================

-- Simple tuple destructuring

match (1, 2) {

(x, y) => x + y

}

-- Output: 3

-- Nested tuples

match ((1, 2), (3, 4)) {

((a, b), (c, d)) => a + b + c + d

}

-- Output: 10

-- =======================

-- LITERAL PATTERNS

-- =======================

-- Integer literals

match 42 {

0 => "zero",

42 => "forty-two",

_ => "other"

}

-- Output: "forty-two"

-- String literals

match "hello" {

"hello" => "greeting",

"goodbye" => "farewell",

_ => "unknown"

}

-- Output: "greeting"

-- Boolean literals

match true {

true => "yes",

false => "no"

}

-- Output: "yes"

-- =======================

-- VARIABLE PATTERNS

-- =======================

-- Binding values to variables

match 100 {

x => x * 2

}

-- Output: 200

-- =======================

-- WILDCARD PATTERNS

-- =======================

-- Catch-all pattern

match 999 {

0 => "zero",

1 => "one",

_ => "many"

}

-- Output: "many"

-- =======================

-- ADT CONSTRUCTOR PATTERNS

-- =======================

type Option[a] = Some(a) | None

-- Matching constructors with fields

match Some(42) {

Some(n) => n * 2,

None => 0

}

-- Output: 84

-- Matching nullary constructors

match None {

Some(n) => n,

None => -1

}

-- Output: -1

-- =======================

-- NESTED PATTERNS

-- =======================

type Result[a, e] = Ok(a) | Err(e)

-- Nested ADT patterns

match Ok(Some(42)) {

Ok(Some(n)) => n,

Ok(None) => 0,

Err(e) => -1

}

-- Output: 42

-- Tuple with ADT patterns

match (Some(1), Some(2)) {

(Some(x), Some(y)) => x + y,

(Some(x), None) => x,

(None, Some(y)) => y,

(None, None) => 0

}

-- Output: 3

-- =======================

-- COMPLEX EXAMPLES

-- =======================

-- Pattern matching in expressions

let result = match (10, 20) {

(0, y) => y,

(x, 0) => x,

(x, y) => x + y

} in

result

-- Output: 30