Where is Ruby's string literal juxtaposition feature officially documented?

Question

I recently realized that if you juxtapose a sequence of Ruby string literals (e.g. \'a\' \"b\" \'c\'), it\'s equivalent to the concatenation of those string lit

Answer 1

In addition to the pickaxe reference, there are some unit tests:

# compile time string concatenation
assert_equal("abcd", "ab" "cd")
assert_equal("22aacd44", "#{22}aa" "cd#{44}")
assert_equal("22aacd445566", "#{22}aa" "cd#{44}" "55" "#{66}")