wac_parser/ast/
let.rs

1use super::{parse_token, DocComment, Expr, Ident, Lookahead, Parse, ParseResult, Peek};
2use crate::lexer::{Lexer, Token};
3use serde::Serialize;
4
5/// Represents a let statement in the AST.
6#[derive(Debug, Clone, Serialize)]
7#[serde(rename_all = "camelCase")]
8pub struct LetStatement<'a> {
9    /// The doc comments for the statement.
10    pub docs: Vec<DocComment<'a>>,
11    /// The newly bound identifier.
12    pub id: Ident<'a>,
13    /// The expression being bound.
14    pub expr: Expr<'a>,
15}
16
17impl<'a> Parse<'a> for LetStatement<'a> {
18    fn parse(lexer: &mut Lexer<'a>) -> ParseResult<Self> {
19        let docs = Parse::parse(lexer)?;
20        parse_token(lexer, Token::LetKeyword)?;
21        let id = Parse::parse(lexer)?;
22        parse_token(lexer, Token::Equals)?;
23        let expr = Parse::parse(lexer)?;
24        parse_token(lexer, Token::Semicolon)?;
25        Ok(Self { docs, id, expr })
26    }
27}
28
29impl Peek for LetStatement<'_> {
30    fn peek(lookahead: &mut Lookahead) -> bool {
31        lookahead.peek(Token::LetKeyword)
32    }
33}
34
35#[cfg(test)]
36mod test {
37    use crate::ast::test::roundtrip;
38
39    #[test]
40    fn let_statement_roundtrip() {
41        roundtrip(
42            "package foo:bar; let x= y;",
43            "package foo:bar;\n\nlet x = y;\n",
44        )
45        .unwrap();
46        roundtrip(
47            "package foo:bar; let x =y.x.z;",
48            "package foo:bar;\n\nlet x = y.x.z;\n",
49        )
50        .unwrap();
51        roundtrip(
52            "package foo:bar; let x=y[\"x\"][\"z\"];",
53            "package foo:bar;\n\nlet x = y[\"x\"][\"z\"];\n",
54        )
55        .unwrap();
56        roundtrip(
57            "package foo:bar; let x = foo[\"bar\"].baz[\"qux\"];",
58            "package foo:bar;\n\nlet x = foo[\"bar\"].baz[\"qux\"];\n",
59        )
60        .unwrap();
61
62        roundtrip(
63            "package foo:bar; let x = (y);",
64            "package foo:bar;\n\nlet x = (y);\n",
65        )
66        .unwrap();
67
68        roundtrip(
69            "package foo:bar; let x = new foo:bar {};",
70            "package foo:bar;\n\nlet x = new foo:bar {};\n",
71        )
72        .unwrap();
73
74        roundtrip(
75            "package foo:bar; let x = new foo:bar { foo, \"bar\": (new baz:qux {...}), \"baz\": foo[\"baz\"].qux };",
76            "package foo:bar;\n\nlet x = new foo:bar {\n    foo,\n    \"bar\": (new baz:qux { ... }),\n    \"baz\": foo[\"baz\"].qux,\n};\n",
77        )
78        .unwrap();
79
80        roundtrip(
81            "package foo:bar; let x = new foo:bar { foo, ...i, bar: baz, ...i2, ...,};",
82            "package foo:bar;\n\nlet x = new foo:bar {\n    foo,\n    ...i,\n    bar: baz,\n    ...i2,\n    ...\n};\n",
83        )
84        .unwrap();
85    }
86}
wac_parser/ast/let.rs

wac_parser/ast/
let.rs
