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use crate::ast;
use crate::{ParseError, Parser, Spanned, ToTokens};
/// A let expression `let <name> = <expr>;`
///
/// # Examples
///
/// ```rust
/// use rune::{testing, ast};
///
/// testing::roundtrip::<ast::ExprLet>("let x = 1");
/// testing::roundtrip::<ast::ExprLet>("#[attr] let a = f()");
/// ```
#[derive(Debug, Clone, PartialEq, Eq, ToTokens, Spanned)]
pub struct ExprLet {
/// The attributes for the let expression
#[rune(iter)]
pub attributes: Vec<ast::Attribute>,
/// The `let` keyword.
pub let_token: T![let],
/// The name of the binding.
pub pat: ast::Pat,
/// The equality keyword.
pub eq: T![=],
/// The expression the binding is assigned to.
pub expr: ast::Expr,
}
impl ExprLet {
/// Parse with the given meta.
pub fn parse_with_meta(
parser: &mut Parser<'_>,
attributes: Vec<ast::Attribute>,
) -> Result<Self, ParseError> {
Ok(Self {
attributes,
let_token: parser.parse()?,
pat: parser.parse()?,
eq: parser.parse()?,
expr: ast::Expr::parse_without_eager_brace(parser)?,
})
}
/// Parse a let expression without eager bracing.
pub fn parse_without_eager_brace(parser: &mut Parser) -> Result<Self, ParseError> {
Ok(Self {
attributes: vec![],
let_token: parser.parse()?,
pat: parser.parse()?,
eq: parser.parse()?,
expr: ast::Expr::parse_without_eager_brace(parser)?,
})
}
}
expr_parse!(Let, ExprLet, "let expression");