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

use core::fmt;

use crate::{
    path::Path,
    value::{StringOrRef, ValueOrRef},
};

/// True if the attribute specified by `path` begins with a particular substring.
///
/// [DynamoDB documentation](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.OperatorsAndFunctions.html#Expressions.OperatorsAndFunctions.Functions)
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct BeginsWith {
    // `Path` is correct here
    // https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.OperatorsAndFunctions.html#Expressions.OperatorsAndFunctions.Syntax
    pub(crate) path: Path,
    pub(crate) substr: ValueOrRef,
}

impl BeginsWith {
    pub fn new<P, S>(path: P, substr: S) -> Self
    where
        P: Into<Path>,
        // Per the docs below, this can be a string or a reference to an expression attribute value.
        //
        // > True if the attribute specified by path begins with a particular substring.
        // >
        // > Example: Check whether the first few characters of the front view picture URL are http://.
        // >
        // > begins_with (Pictures.FrontView, :v_sub)
        // >
        // > The expression attribute value :v_sub is a placeholder for http://.
        //
        // Source: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.OperatorsAndFunctions.html#Expressions.OperatorsAndFunctions.Functions
        S: Into<StringOrRef>,
    {
        Self {
            path: path.into(),
            substr: substr.into().into(),
        }
    }
}

impl fmt::Display for BeginsWith {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "begins_with({}, {})", self.path, self.substr)
    }
}