Function toql_core::map_key::map_key

source · [−]

pub fn map_key<I: Iterator>(xs: I) -> MapKeyIter<I>ⓘNotable traits for MapKeyIter<I>impl<I> Iterator for MapKeyIter<I> where
    I: Iterator,
    I::Item: Keyed,     type Item = <I::Item as Keyed>::Key;

Expand description

Takes a list of entities and turn them into keys. This can also be used to create key predicates.

Example

Basic collection of keys
Building a key predicate for a Toql query

use toql_derive::Toql;
use toql_core::{map_key::MapKey, query::Query};

#[derive(Toql)]
struct User {
    #[toql(key)]
    id: u64,
    name: String
}

 let users = vec![User{id:5, name: "Joe".to_string()}, User{id:7, name: "Sue".to_string()}];
 let keys = users.iter().map_key().collect::<Vec<_>>(); // Returns Vec<UserKey>
 let predicate = users.iter().map_key().collect::<Query>(); // Build query

 assert_eq!(predicate.to_string, "(id eq 5;id eq 7)");

Notice that when keys are be collected into a Query the predicates are concatenated with OR.