rune/ast/
expr_object.rs

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1use crate::alloc::borrow::Cow;
2use crate::ast::prelude::*;
3
4#[test]
5#[cfg(not(miri))]
6fn ast_parse() {
7    rt::<ast::ExprObject>("Foo {\"foo\": 42}");
8    rt::<ast::ExprObject>("#{\"foo\": 42}");
9    rt::<ast::ExprObject>("#{\"foo\": 42,}");
10
11    rt::<ast::FieldAssign>("\"foo\": 42");
12    rt::<ast::FieldAssign>("\"foo\": 42");
13    rt::<ast::FieldAssign>("\"foo\": 42");
14
15    rt::<ast::ObjectKey>("foo");
16    rt::<ast::ObjectKey>("\"foo \\n bar\"");
17}
18
19/// An object expression.
20///
21/// * `#{ [field]* }`.
22/// * `Object { [field]* }`.
23#[derive(Debug, TryClone, PartialEq, Eq, Parse, ToTokens, Spanned)]
24#[non_exhaustive]
25pub struct ExprObject {
26    /// Attributes associated with object.
27    #[rune(iter, meta)]
28    pub attributes: Vec<ast::Attribute>,
29    /// An object identifier.
30    #[rune(meta)]
31    pub ident: ObjectIdent,
32    /// Assignments in the object.
33    pub assignments: ast::Braced<FieldAssign, T![,]>,
34}
35
36impl Peek for ExprObject {
37    fn peek(p: &mut Peeker<'_>) -> bool {
38        match (p.nth(0), p.nth(1)) {
39            (K![ident], K!['{']) => true,
40            (K![#], K!['{']) => true,
41            _ => false,
42        }
43    }
44}
45
46/// A literal object identifier.
47#[derive(Debug, TryClone, PartialEq, Eq, ToTokens, Spanned)]
48#[non_exhaustive]
49pub enum ObjectIdent {
50    /// An anonymous object.
51    Anonymous(T![#]),
52    /// A named object.
53    Named(ast::Path),
54}
55
56impl Parse for ObjectIdent {
57    fn parse(p: &mut Parser<'_>) -> Result<Self> {
58        Ok(match p.nth(0)? {
59            K![#] => Self::Anonymous(p.parse()?),
60            _ => Self::Named(p.parse()?),
61        })
62    }
63}
64
65/// A single field assignment in an object expression.
66#[derive(Debug, TryClone, PartialEq, Eq, ToTokens, Spanned)]
67#[non_exhaustive]
68pub struct FieldAssign {
69    /// The key of the field.
70    pub key: ObjectKey,
71    /// The assigned expression of the field.
72    #[rune(iter)]
73    pub assign: Option<(T![:], ast::Expr)>,
74}
75
76impl Parse for FieldAssign {
77    fn parse(p: &mut Parser<'_>) -> Result<Self> {
78        let key = p.parse()?;
79
80        let assign = if p.peek::<T![:]>()? {
81            let colon = p.parse()?;
82            let expr = p.parse::<ast::Expr>()?;
83            Some((colon, expr))
84        } else {
85            None
86        };
87
88        Ok(Self { key, assign })
89    }
90}
91
92/// Possible literal object keys.
93#[derive(Debug, TryClone, PartialEq, Eq, ToTokens, Spanned)]
94#[non_exhaustive]
95pub enum ObjectKey {
96    /// A literal string (with escapes).
97    LitStr(ast::LitStr),
98    /// A path, usually an identifier.
99    Path(ast::Path),
100}
101
102impl Parse for ObjectKey {
103    fn parse(p: &mut Parser<'_>) -> Result<Self> {
104        Ok(match p.nth(0)? {
105            K![str] => Self::LitStr(p.parse()?),
106            K![ident] => Self::Path(p.parse()?),
107            _ => {
108                return Err(compile::Error::expected(p.tok_at(0)?, "literal object key"));
109            }
110        })
111    }
112}
113
114impl<'a> Resolve<'a> for ObjectKey {
115    type Output = Cow<'a, str>;
116
117    fn resolve(&self, cx: ResolveContext<'a>) -> Result<Self::Output> {
118        Ok(match self {
119            Self::LitStr(lit_str) => lit_str.resolve(cx)?,
120            Self::Path(path) => {
121                let ident = match path.try_as_ident() {
122                    Some(ident) => ident,
123                    None => {
124                        return Err(compile::Error::expected(path, "object key"));
125                    }
126                };
127
128                Cow::Borrowed(ident.resolve(cx)?)
129            }
130        })
131    }
132}
rune/ast/expr_object.rs

rune/ast/
expr_object.rs
