toasty_core/stmt/
expr_arg.rs

1use super::Expr;
2
3/// A positional argument placeholder.
4///
5/// Represents a reference to an input value by position. During substitution,
6/// `arg(n)` is replaced with the nth value from the input.
7///
8/// # Examples
9///
10/// ```text
11/// arg(0)  // refers to the first input value
12/// arg(1)  // refers to the second input value
13/// ```
14#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
15pub struct ExprArg {
16    /// The zero-based position of the argument.
17    pub position: usize,
18
19    /// Which "argument scope" this references. This is the number of scopes up
20    /// from the current scope. Scopes are created by functional expressions
21    /// like Expr::Map.
22    pub nesting: usize,
23}
24
25impl Expr {
26    pub fn arg(expr_arg: impl Into<ExprArg>) -> Self {
27        Self::Arg(expr_arg.into())
28    }
29}
30
31impl ExprArg {
32    pub fn new(position: usize) -> ExprArg {
33        ExprArg {
34            position,
35            nesting: 0,
36        }
37    }
38}
39
40impl From<usize> for ExprArg {
41    fn from(value: usize) -> Self {
42        Self {
43            position: value,
44            nesting: 0,
45        }
46    }
47}
48
49impl From<ExprArg> for Expr {
50    fn from(value: ExprArg) -> Self {
51        Self::Arg(value)
52    }
53}
toasty_core/stmt/expr_arg.rs

toasty_core/stmt/
expr_arg.rs
