sql_fun_sqlast/syn/
syn_ext.rs

1/// conversion support trait for syn object
2pub trait Opt<T> {
3    /// get reference of inner value
4    fn as_inner(&self) -> Option<T>;
5
6    /// covert to inner value
7    fn unwrap(&self) -> T {
8        self.as_inner().unwrap()
9    }
10
11    /// get inner value
12    ///
13    /// # Errors
14    ///
15    /// - `err` if item is None
16    ///
17    fn ok_or_else<E, F>(&self, err: F) -> Result<T, E>
18    where
19        F: FnOnce() -> E,
20    {
21        self.as_inner().ok_or_else(err)
22    }
23
24    /// covert item with function
25    fn map<U, F>(&self, f: F) -> Option<U>
26    where
27        F: FnOnce(T) -> U,
28    {
29        self.as_inner().map(f)
30    }
31}
32
33/// conversion support trait for syn object list
34pub trait ListOpt<T: Clone> {
35    /// internal value type
36    type OptType: From<Option<T>>;
37
38    /// get reference of inner value
39    fn as_inner(&self) -> Option<Vec<T>>;
40
41    /// get zero based index entry
42    fn get(&self, index: usize) -> Self::OptType {
43        let Some(inner) = self.as_inner() else {
44            return Self::OptType::from(None);
45        };
46
47        Self::OptType::from(inner.get(index).cloned())
48    }
49
50    /// convert list items
51    fn map<U, F, V>(&self, f: F) -> Option<Vec<U>>
52    where
53        F: Fn(T) -> V,
54        V: Opt<U>,
55    {
56        let inner = self.as_inner()?;
57        Some(
58            inner
59                .iter()
60                .cloned()
61                .filter_map(|v| f(v).as_inner())
62                .collect(),
63        )
64    }
65
66    /// covert list items
67    fn map_values<U, F>(&self, f: F) -> Option<Vec<U>>
68    where
69        F: Fn(T) -> Option<U>,
70    {
71        let inner = self.as_inner()?;
72        Some(inner.iter().cloned().filter_map(f).collect())
73    }
74}
sql_fun_sqlast/syn/syn_ext.rs

sql_fun_sqlast/syn/
syn_ext.rs
