rational.rb: avoid 'NaNi` representation.
Use `NaN*i` as CRuby does.
@@ -8,7 +8,7 @@ class Complex < Numeric
end
def to_s
- "#{real}#{'+' unless imaginary < 0}#{imaginary}i"
+ "#{real}#{'+' unless imaginary < 0}#{imaginary}#{'*' unless imaginary.finite?}i"
end
def +@
