brackets from cold

gistfile1.txt

# any idea what's going on here?

>> ()
=> nil
>> (true)
=> true
>> ('string')
=> 'string'
>> (true,false)
SyntaxError: compile error
(irb):10: Can't assign to true
(true,false)
      ^
(irb):10: Can't assign to false
(irb):10: syntax error, unexpected '\n', expecting '='
	from (irb):10
>> (a,b)
SyntaxError: compile error
(irb):11: syntax error, unexpected '\n', expecting '='
	from (irb):11
>> (a,'a')
SyntaxError: compile error
(irb):12: syntax error, unexpected ')', expecting tCOLON2 or '[' or '.'
	from (irb):12

Ignoring the paranthesis, it's expecting true, false\n to be a parallel variable assignment i.e.

a, b = c, d

but it's telling you off for trying to assign to true or false (they're immutable so unassignable) and then also telling you off for not putting in an equal sign to do parallel assignment with.

Similarly, if you do a, b\n then it expects an = for parallel assignment. The last one is right-evaluating the string 'a' and saying "You should put a colon here for hash assignment i.e. 'a': 'b' or you should be using the [] to access an element within this string e.g. 'a'[0] = 'a' or you should be using a dot and calling some string instance method on 'a' e.g. 'a'.upcase.