Almost all syntactic elements in Pangaea are expressions, which do not require line breaks. The only exceptions are jump statements.
Jump statements relates to the end of function evaluation.
return ends function evaluation immidiately and returns value to the caller.
{|i|
return i * 2
i.p # never evaluated
}(3).p # 6
Combined to if, you can write guard.
fact := {|n|
return 1 if n == 0
n * fact(n - 1)
}
fact(5).p # 120
yield is used in iterators.
It sets returns value to the caller but keeps evaluation. Also, yield if raises StopIterErr if the condition is false.
<{|n|
yield n if n < 4 # set n to return value but keeps evaluation
recur(n+1)
}>.new(1)@p
# 1
# 2
# 3
raise is used to raise an error.
It works similar to return but it unwraps error wrapper and raises it again (see Error handling for details).
neg := {|n|
raise TypeErr.new("n must be int") if !(n.kindOf?(Int))
-n
}
defer does not return anything. Instead, it sets expressions which will be evaluated after the end of function evaluation.
{|n|
# defer statements are evaluated after return
defer "--logging--".p
defer "n: #{n}".p
return (n *= 2)
}(3).p
# --logging--
# n: 6
# 6
{
defer "--logging--".p # evaluated after raise
raise Err.new("bang!")
}()