fn assignment()

in guard/src/rules/parser.rs [1148:1194]

• 43 lines of code
• 5 McCabe index (conditional complexity)

fn assignment(input: Span) -> IResult<Span, LetExpr> {
    let (input, _let_keyword) = tag("let")(input)?;
    let (input, (var_name, _eq_sign)) = tuple((
        //
        // if we have a pattern like "letproperty" that can be an access keyword
        // then there is no space in between. This will error out.
        //
        preceded(one_or_more_ws_or_comment, var_name),
        //
        // if we succeed in reading the form "let <var_name>", it must be be
        // followed with an assignment sign "=" or ":="
        //
        cut(
            preceded(
                zero_or_more_ws_or_comment,
                alt((tag("="), tag(":=")))
            )
        ),
    ))(input)?;

    match parse_value(input) {
        Ok((input, value)) => Ok((input, LetExpr {
            var: var_name,
            value: LetValue::Value(value)
        })),

        Err(nom::Err::Error(_)) => {
            //
            // if we did not succeed in parsing a value object, then
            // if must be an access pattern, else it is a failure
            //
            let (input, access) = cut(
                preceded(
                    zero_or_more_ws_or_comment,
                    access
                )
            )(input)?;

            Ok((input, LetExpr {
                var: var_name,
                value: LetValue::AccessClause(access),
            }))
        },

        Err(e) => Err(e)
    }
}