std.data.json formal review

[Sönke Ludwig via Digitalmars-d]

Am 29.07.2015 um 20:44 schrieb Walter Bright:
> On 7/29/2015 1:37 AM, Sönke Ludwig wrote:
>> There are actually even four levels:
>> 1. Range of characters
>> 2. Range of tokens
>> 3. Range of nodes
>> 4. DOM value
>
> What's the need for users to see a token stream? I don't know what the
> DOM value is - is that just JSON as an ast?

Yes.

>> Having a special case for range of DOM values may or may not be a
>> worthwhile
>> thing to optimize for handling big JSON arrays of values.
>
> I see no point for that.

Hm, I misread "container of JSON values" as "range of JSON values". I 
guess you just meant JSONValue, so my comment doesn't apply.

>> Currently not all, but most, conversions between the levels are
>> implemented, and
>> sometimes a level is skipped for efficiency. The question is if it
>> would be
>> worth the effort and the API complexity to implement all of them.
>>
>> lexJSON: character range -> token range
>> parseJSONStream: character range -> node range
>> parseJSONStream: token range -> node range
>> parseJSONValue: character range -> DOM value
>> parseJSONValue: token range -> DOM value (same for toJSONValue)
>> writeJSON: token range -> character range (output range)
>> writeJSON: node range -> character range (output range)
>> writeJSON: DOM value -> character range (output range)
>> writeJSON: to -> character range (output range)
>> (same for toJSON with string output)
>
> I don't see why there are more than the 3 I mentioned.

The token level is useful for reasoning about the text representation. 
It could be used for example to implement syntax highlighting, or for 
using the location information to mark errors in the source code.