A fast and minimal JSON parser and transformer that works on unstructured json. Example use cases:
- Walk through unstructured json:
- Print all keys and values
- Extract some values
- Transform unstructured json:
without fully unmarshalling it into a map[string]interface{}.
See usage and examples on godoc.org.
CAUTION: Behaviour is undefined on invalid json. Use on trusted input only.
The single most important function is Walk(input, callback),
which parses the input json and call callback function for each key/value
pair processed.
Let's see an example:
{
"id": 12345,
"name": "foo",
"numbers": ["one", "two"],
"tags": {"color": "red", "priority": "high"},
"active": true
}Calling Walk() with the above input will produce:
| indent | key | value |
|---|---|---|
0 |
{ |
|
1 |
"id" |
12345 |
1 |
"name" |
"foo" |
1 |
"numbers" |
[ |
2 |
"one" |
|
2 |
"two" |
|
1 |
] |
|
1 |
"tags" |
{ |
2 |
"color" |
"red" |
2 |
"priority" |
"high" |
1 |
} |
|
1 |
"active" |
true |
0 |
} |
indent indicates the indentation of the key/value pair as if the json is
formatted properly. keys and values are provided as raw literal. Strings are
always double-quoted. To get the original string, use
Unquote().
value will never be empty (for valid json). You can test the first byte
(value[0]) to get its type:
n: Null (null)f,t: Boolean (false,true)0-9: Number": String, seeUnquote()[,]: Array{,}: Object
When processing arrays and objects, first the open bracket ([, {) will be
provided as value, followed by its children, and finally the close bracket
(], }). When encounting open brackets, You can make the callback function
return false to skip the array/object entirely.