fn parse_select_item_for_data_load()

in src/dialect/snowflake.rs [907:974]

• 58 lines of code
• 3 McCabe index (conditional complexity)

fn parse_select_item_for_data_load(
    parser: &mut Parser,
) -> Result<StageLoadSelectItem, ParserError> {
    let mut alias: Option<Ident> = None;
    let mut file_col_num: i32 = 0;
    let mut element: Option<Ident> = None;
    let mut item_as: Option<Ident> = None;

    let next_token = parser.next_token();
    match next_token.token {
        Token::Placeholder(w) => {
            file_col_num = w.to_string().split_off(1).parse::<i32>().map_err(|e| {
                ParserError::ParserError(format!("Could not parse '{w}' as i32: {e}"))
            })?;
            Ok(())
        }
        Token::Word(w) => {
            alias = Some(Ident::new(w.value));
            Ok(())
        }
        _ => parser.expected("alias or file_col_num", next_token),
    }?;

    if alias.is_some() {
        parser.expect_token(&Token::Period)?;
        // now we get col_num token
        let col_num_token = parser.next_token();
        match col_num_token.token {
            Token::Placeholder(w) => {
                file_col_num = w.to_string().split_off(1).parse::<i32>().map_err(|e| {
                    ParserError::ParserError(format!("Could not parse '{w}' as i32: {e}"))
                })?;
                Ok(())
            }
            _ => parser.expected("file_col_num", col_num_token),
        }?;
    }

    // try extracting optional element
    match parser.next_token().token {
        Token::Colon => {
            // parse element
            element = Some(Ident::new(match parser.next_token().token {
                Token::Word(w) => Ok(w.value),
                _ => parser.expected("file_col_num", parser.peek_token()),
            }?));
        }
        _ => {
            // element not present move back
            parser.prev_token();
        }
    }

    // as
    if parser.parse_keyword(Keyword::AS) {
        item_as = Some(match parser.next_token().token {
            Token::Word(w) => Ok(Ident::new(w.value)),
            _ => parser.expected("column item alias", parser.peek_token()),
        }?);
    }

    Ok(StageLoadSelectItem {
        alias,
        file_col_num,
        element,
        item_as,
    })
}