Tailwind logic macro

tw.rs

#[macro_export]
macro_rules! tw {
    // Base case: when there are no tokens left, return an empty string.
    () => (String::new());

    // New case: handle static string literals
    ($static:literal ; $($rest:tt)*) => {{
        let mut class = String::from($static);
        let rest_classes = tw!($($rest)*);
        if !rest_classes.is_empty() {
            class.push_str(" ");
        }
        class.push_str(&rest_classes);
        class
    }};

    // Case with a condition, a true class, and an optional false class, all followed by more tokens.
    ($cond:expr => $true_class:expr $( , $false_class:expr )? ; $($rest:tt)*) => {{
        let mut class = String::new();

        if $cond {
            class.push_str($true_class);
        } else {
            $( class.push_str($false_class); )?
        }

        // Recursively process any remaining tokens, ensuring we separate classes with a space if needed.
        let rest_classes = tw!($($rest)*);
        if !class.is_empty() && !rest_classes.is_empty() {
            class.push_str(" ");
        }
        class.push_str(&rest_classes);

        class
    }};

    // Case with a condition and a true class, without a false class and without more tokens.
    ($cond:expr => $true_class:expr) => {{
        if $cond {
            $true_class.to_string()
        } else {
            String::new()
        }
    }};
}

Macro to allow static, dynamic and conditional concatination

  tw!(
    "w-full h-full";
    is_active => "text-blue-500", "text-gray-500";
    has_bg => "bg-green-100";
  )