oso 0.27.3

oso is an open source policy engine for authorization that’s embedded in your application
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

use polar_core::terms::*;
use std::collections::hash_map::HashMap;

use crate::host::{Host, Instance};

/// An enum of the possible value types that can be
/// sent to/from Polar.
///
/// All variants except `Instance` represent types that can
/// be used natively in Polar.
/// Any other types can be wrapped using `PolarValue::new_from_instance`.
/// If the instance has a registered `Class`, then this can be used
/// from the policy too.
#[derive(Clone, Debug)]
pub enum PolarValue {
    Integer(i64),
    Float(f64),
    String(String),
    Boolean(bool),
    Map(HashMap<String, PolarValue>),
    List(Vec<PolarValue>),
    Variable(String),
    Instance(Instance),
}

impl PartialEq for PolarValue {
    fn eq(&self, other: &PolarValue) -> bool {
        match (self, other) {
            (PolarValue::Boolean(b1), PolarValue::Boolean(b2)) => b1 == b2,
            (PolarValue::Float(f1), PolarValue::Float(f2)) => f1 == f2,
            (PolarValue::Integer(i1), PolarValue::Integer(i2)) => i1 == i2,
            (PolarValue::List(l1), PolarValue::List(l2)) => l1 == l2,
            (PolarValue::Map(m1), PolarValue::Map(m2)) => m1 == m2,
            (PolarValue::String(s1), PolarValue::String(s2)) => s1 == s2,
            _ => false,
        }
    }
}

impl PolarValue {
    /// Create a `PolarValue::Instance` from any type.
    pub fn new_from_instance<T>(instance: T) -> Self
    where
        T: Send + Sync + 'static,
    {
        Self::Instance(Instance::new(instance))
    }

    pub(crate) fn from_term(term: &Term, host: &Host) -> crate::Result<Self> {
        let val = match term.value() {
            Value::Number(Numeric::Integer(i)) => PolarValue::Integer(*i),
            Value::Number(Numeric::Float(f)) => PolarValue::Float(*f),
            Value::String(s) => PolarValue::String(s.clone()),
            Value::Boolean(b) => PolarValue::Boolean(*b),
            Value::Dictionary(dict) => {
                let mut map = HashMap::new();
                for (k, v) in &dict.fields {
                    let key = k.0.clone();
                    let value = PolarValue::from_term(v, host)?;
                    map.insert(key, value);
                }
                PolarValue::Map(map)
            }
            Value::ExternalInstance(instance) => {
                PolarValue::Instance(host.get_instance(instance.instance_id)?.clone())
            }
            Value::List(l) => {
                let mut list = vec![];
                for t in l {
                    list.push(PolarValue::from_term(t, host)?);
                }
                PolarValue::List(list)
            }
            Value::Variable(Symbol(sym)) => PolarValue::Variable(sym.clone()),
            Value::Expression(_) => {
                return Err(crate::OsoError::Custom {
                    message: r#"
Received Expression from Polar VM. The Expression type is not yet supported in this language.

This may mean you performed an operation in your policy over an unbound variable.
                        "#
                    .to_owned(),
                })
            }
            _ => {
                return Err(crate::OsoError::Custom {
                    message: "Unsupported value type".to_owned(),
                })
            }
        };
        Ok(val)
    }

    pub(crate) fn to_term(&self, host: &mut Host) -> Term {
        let value = match self {
            PolarValue::Integer(i) => Value::Number(Numeric::Integer(*i)),
            PolarValue::Float(f) => Value::Number(Numeric::Float(*f)),
            PolarValue::String(s) => Value::String(s.clone()),
            PolarValue::Boolean(b) => Value::Boolean(*b),
            PolarValue::Map(map) => {
                let mut dict = Dictionary::new();
                for (k, v) in map {
                    let key = Symbol(k.clone());
                    let value = v.to_term(host);
                    dict.fields.insert(key, value);
                }
                Value::Dictionary(dict)
            }
            PolarValue::Instance(instance) => {
                let id = host.cache_instance(instance.clone(), None);
                Value::ExternalInstance(ExternalInstance {
                    constructor: None,
                    instance_id: id,
                    repr: Some(std::any::type_name::<Self>().to_owned()),
                    class_repr: Some(std::any::type_name::<Self>().to_owned()),
                    class_id: None,
                })
            }
            PolarValue::List(l) => {
                let mut list = vec![];
                for v in l {
                    list.push(v.to_term(host))
                }
                Value::List(list)
            }
            PolarValue::Variable(s) => Value::Variable(Symbol(s.clone())),
        };
        Term::new_from_ffi(value)
    }
}