Pattern Matching Syntax Examples

pattern-matching-syntax-examples.rb

# Current
case obj
when String
  "String"
else
  "Other"
end

# Deconstructing
case obj
when :ok, 42
  "42"
else
  "Other"
end

# Deconstructing with implicit assignment
case obj
when :ok, x
  "Result: #{x}"
else
  "Other"
end

# Deconstructing with express assignment
case obj
when :ok, 42 as status, result
  "Status: #{status}, Result: #{result}"
else
  "Other"
end

# Deconstructing with implicit assignment and guard
case obj
when :ok, x if x < 100
  "Result: #{x}"
else
  "Other"
end

# Deconstructing with pinning and express assignment
case obj
when :ok, ^x as _, result
  "x: #{result}"
else
  "Other"
end