How to identify which serialized format is this?

Question

I'm trying to parse some CSV file that has some elements with this format (Below I show 2 examples)

{ :{a:{-} b:{c:{6} d:{-} } e:{-} f:{-}  } }
{ a:{b:{c:{123} } } }

Below in vertical form only in order for you to visualize better.

{ :                   || {                   
    {                 ||    a:{              
        a:{-}         ||        b:{          
        b:{           ||            c:{123}  
            c:{6}     ||        }            
            d:{-}     ||    }                
            }         || }                   
        e:{-}         ||                     
        f:{-}         ||                     
    }                 ||                     
}                     ||                     

At first sight I thought it was JSON format, but is not JSON. I checked the formats shown here but I didn't find something similar.

Is there a way to identify if it is some known format similar to JSON? Thank in advance.