zen-expression 0.55.0

Zen Expression Language
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

use crate::functions::defs::FunctionDefinition;
use crate::functions::{DeprecatedFunction, FunctionKind, InternalFunction};
use nohash_hasher::{BuildNoHashHasher, IsEnabled};
use std::cell::RefCell;
use std::collections::HashMap;
use std::rc::Rc;
use strum::IntoEnumIterator;

impl IsEnabled for InternalFunction {}
impl IsEnabled for DeprecatedFunction {}

pub struct FunctionRegistry {
    internal_functions:
        HashMap<InternalFunction, Rc<dyn FunctionDefinition>, BuildNoHashHasher<InternalFunction>>,
    deprecated_functions: HashMap<
        DeprecatedFunction,
        Rc<dyn FunctionDefinition>,
        BuildNoHashHasher<DeprecatedFunction>,
    >,
}

impl FunctionRegistry {
    thread_local!(
        static INSTANCE: RefCell<FunctionRegistry> = RefCell::new(FunctionRegistry::new_internal())
    );

    pub fn get_definition(kind: &FunctionKind) -> Option<Rc<dyn FunctionDefinition>> {
        match kind {
            FunctionKind::Internal(internal) => {
                Self::INSTANCE.with_borrow(|i| i.internal_functions.get(&internal).cloned())
            }
            FunctionKind::Deprecated(deprecated) => {
                Self::INSTANCE.with_borrow(|i| i.deprecated_functions.get(&deprecated).cloned())
            }
            FunctionKind::Closure(_) => None,
        }
    }

    fn new_internal() -> Self {
        let internal_functions = InternalFunction::iter()
            .map(|i| (i.clone(), (&i).into()))
            .collect();

        let deprecated_functions = DeprecatedFunction::iter()
            .map(|i| (i.clone(), (&i).into()))
            .collect();

        Self {
            internal_functions,
            deprecated_functions,
        }
    }
}