chapter12/

Extend Display so that it can display maps whose keys are structs or arrays

Modify the S-expression encoder (§12.4) and decoder (§12.6) so that they honr the sexpr:"..." field tag in a similar manner to encoding/json.

Make display safe to use on cyclic data structures by bounding the number of steps it takes before abandoning the recursion.

Implement the missing cases of the encode function.

Modify encode to pretty-print the S-expression in the style shown above

Adapt encode to emit JSON instead of S-expressions.

Adapt encode so that as an optimization, it does not encode a field whose value is the zero value of its type

Exercise 12.8: The sexpr.Unmarshal function, like json.Marshal, requires the complete input in a byte slice before it can begin decoding.