control_flow/case_expression_patterns.rb

tests/_examples/control_flow/case_expression_patterns.rb in the metorex repository.

# Case expression with various pattern types

# Array destructuring patterns
arr = [1, 2, 3]
result = case arr
when [a, b, c] then a + b + c
else 0
end
puts result

# Array destructuring with rest pattern
data = [10, 20, 30, 40]
sum = case data
when [first, ...rest] then first
else 0
end
puts sum

# A name written in a when clause stands for what it holds
value = 42
answer = ->(number) { number == 42 }
bound = case value
when answer then value * 2
end
puts bound

# Type pattern matching
obj = 123
type_result = case obj
when Integer then "It's an integer"
when String then "It's a string"
else "Unknown type"
end
puts type_result

# Wildcard pattern
anything = "test"
wild = case anything
when _ then "matches anything"
end
puts wild

# Hash/Dictionary destructuring
dict = {"x" => 10, "y" => 20}
point_sum = case dict
when {x: a, y: b} then a + b
else 0
end
puts point_sum

Output:

6
10
84
It's an integer
matches anything
30