Method parse_lambda_params

leanr-syntax/src/parser.rs:371–428

Parse lambda parameters (simpler than def params)

(&mut self)

    /// Parse lambda parameters (simpler than def params)
    fn parse_lambda_params(&mut self) -> crate::Result<Vec<Param>> {
        let mut params = Vec::new();

        loop {
            if self.check(&TokenKind::FatArrow) {
                break;
            }

            let implicit = self.check(&TokenKind::LBrace);

            if implicit {
                self.advance();
                let name = self.parse_ident()?;
                let type_ = if self.check(&TokenKind::Colon) {
                    self.advance();
                    Some(Box::new(self.parse_expr()?))
                } else {
                    None
                };
                self.expect(TokenKind::RBrace)?;

                params.push(Param {
                    span: name.span,
                    names: vec![name],
                    type_,
                    implicit: true,
                });
            } else if self.check(&TokenKind::LParen) {
                self.advance();
                let name = self.parse_ident()?;
                let type_ = if self.check(&TokenKind::Colon) {
                    self.advance();
                    Some(Box::new(self.parse_expr()?))
                } else {
                    None
                };
                self.expect(TokenKind::RParen)?;

                params.push(Param {
                    span: name.span,
                    names: vec![name],
                    type_,
                    implicit: false,
                });
            } else {
                // Simple name without parens
                let name = self.parse_ident()?;
                params.push(Param {
                    span: name.span,
                    names: vec![name],
                    type_: None,
                    implicit: false,
                });
            }
        }

        Ok(params)
    }