Crystal: Tuple of tuples fails to parse

[pbrusco]

{{true, true}, {true, false}} can't be parsed.

[asterite]

This is because {{ ... }} is a macro expression. You need to use a few spaces:

{ {true, true}, {true, false} }

[RX14]

I think this will bite a few people, maybe the compiler should try to detect this and emit an error.

[asterite]

@RX14 excellent idea!

Now the error given is this:

Syntax error in ./foo.cr:1: expecting token ',', not '}'

If you are nesting tuples or hashes you must write them like this:

    { {x, y}, {z, w} } # Note the space after the first curly brace

because {{...}} is parsed as a macro expression.

{{1, 2}, {3, 4}}
    ^