query_macro.rs

use serde_json;

macro_rules! query_type {
    ("fields" => $fields:expr) => {{
        println!("field {:?}", $fields);
        "boom".to_string()
    }};
    (
        {$section:expr => {
            $(
                $key:expr => {
                    $comp:expr => $val:expr
                 }
             ),*
         }
    }) => {{
        
        let mut selector = Map::new();
        $(
            let mut kv = Map::new();
            kv.insert($comp.to_string(), serde_json::to_value($val));
            selector.insert($key.to_string(), kv);
            println!("selector {:?} {:?} {:?}", $key, $comp, $val);
        )*
        selector
    }};
}

macro_rules! query {
    ( {$($section:expr => $content:tt),*} ) => {{
        use serde_json;
        use serde_json::{Map};
        let mut map = Map::new();
        $(
            println!("section {:?}", $section);
            map.insert($section.to_string(), query_type!({$section => $content}));
        )*
        map
    }};
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::{Value};
    use serde_json;

    #[test]
    fn create_selector_query () {
        let query = query!({
            "selector" => {
                "_id" => {
                    "$eq" => "boom"
                },
                "name" => {
                    "$lte" => "garren"
                }
            }
        });

        let _id = query.get("selector").unwrap().get("_id").unwrap();
        let name = query.get("selector").unwrap().get("name").unwrap();
        assert_eq!(_id.get("$eq").unwrap().to_string(), "\"boom\"");
        assert_eq!(name.get("$lte").unwrap().to_string(), "\"garren\"");
    }
}