datex_core/ast/
function.rs

1use crate::ast::lexer::Token;
2use crate::ast::r#type::r#type;
3use crate::ast::utils::whitespace;
4use crate::ast::{DatexExpression, DatexParserTrait, TypeExpression};
5use chumsky::prelude::*;
6
7fn return_type<'a>() -> impl DatexParserTrait<'a, Option<TypeExpression>> {
8    just(Token::Arrow)
9        .padded_by(whitespace())
10        .ignore_then(r#type().padded_by(whitespace()))
11        .map(|ty| ty)
12        .or_not()
13}
14
15fn body<'a>(
16    statements: impl DatexParserTrait<'a>,
17) -> impl DatexParserTrait<'a> {
18    statements
19        .clone()
20        .delimited_by(just(Token::LeftParen), just(Token::RightParen))
21}
22
23fn parameter<'a>() -> impl DatexParserTrait<'a, (String, TypeExpression)> {
24    select! { Token::Identifier(name) => name }
25        .then(
26            just(Token::Colon)
27                .padded_by(whitespace())
28                .ignore_then(r#type().padded_by(whitespace())),
29        )
30        .map(|(name, ty)| (name, ty))
31}
32
33fn parameters<'a>() -> impl DatexParserTrait<'a, Vec<(String, TypeExpression)>>
34{
35    parameter()
36        .padded_by(whitespace())
37        .separated_by(just(Token::Comma).padded_by(whitespace()))
38        .collect()
39        .padded_by(whitespace())
40        .delimited_by(just(Token::LeftParen), just(Token::RightParen))
41        .padded_by(whitespace())
42}
43
44pub fn function<'a>(
45    statements: impl DatexParserTrait<'a>,
46) -> impl DatexParserTrait<'a> {
47    // TODO #358: support error notation
48
49    just(Token::Function)
50        .padded_by(whitespace())
51        .ignore_then(select! { Token::Identifier(name) => name })
52        .then(parameters())
53        .then(return_type())
54        .then(body(statements))
55        .map(|(((name, params), return_type), body)| {
56            DatexExpression::FunctionDeclaration {
57                name,
58                parameters: params,
59                return_type,
60                body: Box::new(body),
61            }
62        })
63}
datex_core/ast/function.rs

datex_core/ast/
function.rs
