cargo_quickinstall/
json_value_ext.rs

1use std::fmt;
2use tinyjson::JsonValue;
3
4pub struct JsonExtError(String);
5
6impl fmt::Display for JsonExtError {
7    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
8        f.write_str(&self.0)
9    }
10}
11
12impl fmt::Debug for JsonExtError {
13    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
14        f.write_str(&self.0)
15    }
16}
17
18impl std::error::Error for JsonExtError {}
19
20impl JsonExtError {
21    fn unexpected(value: &JsonValue, expected: &str) -> Self {
22        JsonExtError(format!(
23            "Expecting {expected}, but found {}",
24            value.get_value_type()
25        ))
26    }
27}
28
29pub trait JsonValueExt {
30    fn get_owned(self, key: &dyn JsonKey) -> Result<JsonValue, JsonExtError>;
31
32    fn try_into_string(self) -> Result<String, JsonExtError>;
33
34    fn get_value_type(&self) -> &'static str;
35}
36
37impl JsonValueExt for JsonValue {
38    fn get_owned(self, key: &dyn JsonKey) -> Result<JsonValue, JsonExtError> {
39        key.extract_from_value(self)
40    }
41
42    fn try_into_string(self) -> Result<String, JsonExtError> {
43        match self {
44            JsonValue::String(s) => Ok(s),
45            value => Err(JsonExtError::unexpected(&value, "String")),
46        }
47    }
48
49    fn get_value_type(&self) -> &'static str {
50        match self {
51            JsonValue::Number(..) => "Number",
52            JsonValue::Boolean(..) => "Boolean",
53            JsonValue::String(..) => "String",
54            JsonValue::Null => "Null",
55            JsonValue::Array(..) => "Array",
56            JsonValue::Object(..) => "Object",
57        }
58    }
59}
60
61pub trait JsonKey {
62    fn extract_from_value(&self, value: JsonValue) -> Result<JsonValue, JsonExtError>;
63}
64
65impl<T: JsonKey> JsonKey for &T {
66    fn extract_from_value(&self, value: JsonValue) -> Result<JsonValue, JsonExtError> {
67        T::extract_from_value(*self, value)
68    }
69}
70
71impl JsonKey for usize {
72    fn extract_from_value(&self, value: JsonValue) -> Result<JsonValue, JsonExtError> {
73        let index = *self;
74
75        match value {
76            JsonValue::Array(mut values) => {
77                let len = values.len();
78
79                if index < len {
80                    Ok(values.swap_remove(index))
81                } else {
82                    Err(JsonExtError(format!(
83                        "Index {index} is too large for array of len {len}",
84                    )))
85                }
86            }
87
88            value => Err(JsonExtError::unexpected(&value, "Array")),
89        }
90    }
91}
92
93impl JsonKey for &str {
94    fn extract_from_value(&self, value: JsonValue) -> Result<JsonValue, JsonExtError> {
95        let key = *self;
96
97        match value {
98            JsonValue::Object(mut map) => map
99                .remove(key)
100                .ok_or_else(|| JsonExtError(format!("Key {key} not found in object"))),
101
102            value => Err(JsonExtError::unexpected(&value, "Object")),
103        }
104    }
105}
cargo_quickinstall/json_value_ext.rs

cargo_quickinstall/
json_value_ext.rs
