Pretty printing a json term

General
1

Finally found that library(http/json) has what I need. The width option controls the thing. I propose that the portray_clause/1 should pretty print json terms using this json_write/3

 json_write(current_output, json([name='Bob', children=['Mary', 'John'], age=42, married= @(true)]),[width(8)]).

Result is

{
  "name":"Bob",
  "children": [
    "Mary",
    "John"
  ],
  "age":42,
  "married":true
}
2

No. portray_clause/1 is defined to print the term such that it is valid syntax and reads back to the original. You do get acceptable results if you use the “dict” variation of the JSON API.

1 Like
3

Thanks.

What I found is to assert a portray/1

?- [library(http/json)].
true.

?-  asserta(portray(json(X)):- (json_write(current_output, json(X),[width(8)]))).
true.

?- print( json([name='Bob', children=['Mary', 'John'], age=42, married= @(true)])).
{
  "name":"Bob",
  "children": [
    "Mary",
    "John"
  ],
  "age":42,
  "married":true
}
true.

Also format(‘~p’ …) prints the json term nicely.

I am happy with this.