Macro postall_helper 

macro_rules! postall_helper {
    ($model:expr,) => { ... };
    ($model:expr, $var:ident < $target:ident) => { ... };
    ($model:expr, $var:ident <= $target:ident) => { ... };
    ($model:expr, $var:ident > $target:ident) => { ... };
    ($model:expr, $var:ident >= $target:ident) => { ... };
    ($model:expr, $var:ident == $target:ident) => { ... };
    ($model:expr, $var:ident != $target:ident) => { ... };
    ($model:expr, $var:ident < int($target:expr)) => { ... };
    ($model:expr, $var:ident <= int($target:expr)) => { ... };
    ($model:expr, $var:ident > int($target:expr)) => { ... };
    ($model:expr, $var:ident >= int($target:expr)) => { ... };
    ($model:expr, $var:ident == int($target:expr)) => { ... };
    ($model:expr, $var:ident != int($target:expr)) => { ... };
    ($model:expr, $left:ident + $right:ident <= $target:ident) => { ... };
    ($model:expr, $left:ident + $right:ident == $target:ident) => { ... };
    ($model:expr, $left:ident + $right:ident <= int($target:expr)) => { ... };
    ($model:expr, $left:ident + $right:ident == int($target:expr)) => { ... };
    ($model:expr, abs($var:ident) >= int($target:expr)) => { ... };
    ($model:expr, abs($var:ident) <= int($target:expr)) => { ... };
    ($model:expr, alldiff([$($vars:ident),+ $(,)?])) => { ... };
    ($model:expr, alldiff($array:expr)) => { ... };
    ($model:expr, and($c1:expr, $c2:expr)) => { ... };
    ($model:expr, or($c1:expr, $c2:expr)) => { ... };
    ($model:expr, not($c:expr)) => { ... };
    ($model:expr, $var:ident < $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $var:ident <= $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $var:ident > $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $var:ident >= $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $var:ident == $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $var:ident != $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $var:ident < int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, $var:ident <= int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, $var:ident > int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, $var:ident >= int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, $var:ident == int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, $var:ident != int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, $left:ident + $right:ident <= $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $left:ident + $right:ident == $target:ident, $($rest:tt)*) => { ... };
    ($model:expr, $left:ident + $right:ident <= int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, $left:ident + $right:ident == int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, abs($var:ident) >= int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, abs($var:ident) <= int($target:expr), $($rest:tt)*) => { ... };
    ($model:expr, alldiff([$($vars:ident),+ $(,)?]), $($rest:tt)*) => { ... };
    ($model:expr, alldiff($array:expr), $($rest:tt)*) => { ... };
    ($model:expr, and($c1:expr, $c2:expr), $($rest:tt)*) => { ... };
    ($model:expr, or($c1:expr, $c2:expr), $($rest:tt)*) => { ... };
    ($model:expr, not($c:expr), $($rest:tt)*) => { ... };
}

Helper macro to handle constraint expressions recursively