Notes/Data/Serialization/JSON_like/JSON/Syntax/json.format.txt at master · dginorg/Notes · GitHub

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                                  ┏━━━━━━━━━━┓
                                  ┃   JSON   ┃
                                  ┗━━━━━━━━━━┛

ALTERNATIVES ==>                                #See serialization formats summary

STANDARDS ==>                                   #ECMA-404
                                                #RFC 8259: more detailed

I-JSON ==>                                      #RFC 7493
                                                #I-JSON ("Internet JSON"), restrictive version of JSON for maximum
                                                #interoperability between parsers.

NOTATION ==>                                   !#Means recommended but implementation-specific
                                              !!#Means recommended but implementation-specific, and required by I-JSON

GOAL ==>                                        #Serialization format based on JavaScript
                                                #Extension: .json
                                                #MIME type: application/json

                                  ┌────────────┐
                                  │   SYNTAX   │
                                  └────────────┘

CASE ==>                                        #Case-sensitive

WHITESPACES|NEWLINES ==>                        #Is space, tab, CR or LF
                                                #Whitespaces|newlines are ignored:
                                                #  - at start|end
                                                #  - between tokens

ENCODING ==>                                    #UTF-8
                                                #No byte-order mark

LIMITS ==>                                     !#Implementation-specific
                                               !#On depth level, input size, STR sixe, ARR|OBJ length, key length

{"VAR": VAL}                                    #OBJ
                                                #Must double-quote "VAR"
                                                #No trailing commas
                                                #VAR: same restrictions as STR
                                              !!#No duplicate keys
                                              !!#Is unordered

[VAL,...]                                       #ARR
                                                #No trailing commas

"..."                                           #STR.
                                                #No single quotes
                                                #Any Unicode supported unescaped except " \ and U+0000-U+001F (\-escaped)
                                                #  - i.e. significant newline must be escaped
                                                #  - U+2028|2029 (line separators) allowed unescaped in JSON and ES2018 (Node >=10),
                                                #    but not in ES2017 or before
                                              !!#  - when used as OBJ key "VAR", must be normalized for duplication check
                                                #Can use backslash sequences (fewer than JavaScript):
                                                #  \" \\ \b \f \n \r \t \/
                                                #  \uXXXX
                                                #    - U+010000-U+10FFFF can only be used unescaped
                                              !!#    - must be valid codepoint

[-]NUM[.NUM][e|E[+|-]NUM]                       #FLOAT.
                                                #No leading comma (e.g. ".7")
                                                #No +NUM
                                                #No Infinity|NaN
                                                #No leading zero (e.g. "07")
                                                #Only base 10
                                                #Not specified:
                                                #  - max size
                                              !!#     - double floats
                                                #  - overflow, underflow, rounding
                                                #  - whether can normalize NUM <-> NUM.0 (INT vs FLOAT)
                                                #  - whether can normalize 0 <-> -0

true|false                                      #BOOL

null                                            #

TOP-LEVEL ==>                                 !!#OBJ|ARR

RECURSION ==>                                   #Not possible.

COMPARISON WITH JAVASCRIPT ==>                  #No undefined, FUNC or native objects (besides OBJ|ARR)
                                                #Can however support others:
                                                #  - if toJSON() defined:
                                                #     - DATE.toJSON()->DATE.toISOString()
                                              !!#       DATE must follow ISO8601/RFC3339, which DATE.toISOString() does
                                              !!#  - binary should be base64 STR (base64url variant)
                                                #  - by calling toString() prior
                                                #  - via JSON.stringify|parse FUNC
                                                #Does not handle any ES6-specific syntax, like { [STR]: VAL }, { VAR }, SYM, etc.
                                                #Unescaped U+2028|2029 in "..." allowed only starting from ES2018