lmao_macros.rs

#[macro_export]
macro_rules! autoparse_struct {
    (
        $(#[$meta:meta])*
        $vis:vis $Name:ident {
            $($inner:tt)*
        }
    ) => {
        autoparse_struct!(@ (reader, [$($meta)*], $vis, $Name): {$($inner)*} -> [], [], []);
    };

    (@ ($reader:ident, [$($meta:meta)*], $vis:vis, $Name:ident): {} -> [$($def:tt)*], [$($parse:tt)*], [$($fields:tt)*]) => {
        $(#[$meta])*
        #[derive(Debug)]
        $vis struct $Name {
            $($def)*
        }

        impl $crate::arinc424::utils::parseable::Parseable for $Name {
            fn parse($reader: &mut $crate::arinc424::utils::string_reader::StringReader) -> Option<Self> {
                $($parse)*

                Some(Self {
                    $($fields)*
                })
            }
        }
    };

    (@ ($reader:ident, $meta:tt, $vis:vis, $Name:ident): {
        $field_vis:vis $field:ident: $Type:ty,
        $($tail:tt)*
    } -> [$($def:tt)*], [$($parse:tt)*], [$($fields:tt)*]) => {
        autoparse_struct!(
            @ ($reader, $meta, $vis, $Name): {$($tail)*} ->
                [$($def)* $field_vis $field: $Type,],
                [$($parse)* let $field = <$Type>::parse($reader)?;],
                [$($fields)* $field,]
        );
    };

    (@ ($reader:ident, $meta:tt, $vis:vis, $Name:ident): {
        $Type:ty where $($pat:pat_param)|+,
        $($tail:tt)*
    } -> [$($def:tt)*], [$($parse:tt)*], [$($fields:tt)*]) => {
        autoparse_struct!(
            @ ($reader, $meta, $vis, $Name): {$($tail)*} ->
                [$($def)*],
                [
                    $($parse)*
                    let value = <$Type>::parse($reader)?;
                    if !matches!(value, $($pat)|+) {
                        return None;
                    }
                ],
                [$($fields)*]
        );
    };

    (@ ($reader:ident, $meta:tt, $vis:vis, $Name:ident): {
        #(skip $count:expr),
        $($tail:tt)*
    } -> [$($def:tt)*], [$($parse:tt)*], [$($fields:tt)*]) => {
        autoparse_struct!(
            @ ($reader, $meta, $vis, $Name): {$($tail)*} ->
                [$($def)*],
                [$($parse)* $reader.skip($count);],
                [$($fields)*]
        );
    };

    (@ ($reader:ident, $meta:tt, $vis:vis, $Name:ident): {
        #(continuation),
        $($tail:tt)*
    } -> [$($def:tt)*], [$($parse:tt)*], [$($fields:tt)*]) => {
        autoparse_struct!(
            @ ($reader, $meta, $vis, $Name): {$($tail)*} ->
                [$($def)*],
                [
                    $($parse)*
                    // Super janky but no real continuation record parsing for now.
                    if $reader.read(1)? != "0" {
                        println!("[skipping continuation record]");
                        return None;
                    }
                ],
                [$($fields)*]
        );
    };
}