Dictionary displays

A dictionary display is a possibly empty series of key/datum pairs enclosed in curly braces:

dict_display:   "{" [key_datum_list] "}"
key_datum_list: key_datum ("," key_datum)* [","]
key_datum:      condition ":" condition

A dictionary display yields a new dictionary object.

The key/datum pairs are evaluated from left to right to define the entries of the dictionary: each key object is used as a key into the dictionary to store the corresponding datum.

Restrictions on the types of the key values are listed earlier in section . Clashes between duplicate keys are not detected; the last datum (textually rightmost in the display) stored for a given key value prevails.