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Rust json! macro
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| use std::collections::HashMap; | |
| #[derive(Debug, PartialEq, Clone)] | |
| enum Json { | |
| Null, | |
| Boolean(bool), | |
| Number(f64), | |
| String(String), | |
| Array(Vec<Json>), | |
| Object(Box<HashMap<String, Json>>), | |
| } | |
| impl From<String> for Json { | |
| fn from(s: String) -> Json { | |
| Json::String(s) | |
| } | |
| } | |
| impl<'a> From<&'a str> for Json { | |
| fn from(s: &'a str) -> Json { | |
| Json::String(s.to_string()) | |
| } | |
| } | |
| macro_rules! impl_num_json { | |
| ( $( $t:ident )+ ) => { | |
| $( | |
| impl From<$t> for Json { | |
| fn from(n: $t) -> Json { | |
| Json::Number(n as f64) | |
| } | |
| } | |
| )+ | |
| } | |
| } | |
| impl_num_json!(u8 i8 u16 i16 u32 i32 u64 i64 usize isize f32 f64); | |
| macro_rules! json { | |
| ( null ) => { Json::Null }; | |
| ( true ) => { Json::Boolean(true) }; | |
| ( false ) => { Json::Boolean(false) }; | |
| ([$( $element:tt ),* ]) => { | |
| Json::Array(vec![$( json!($element) ), *]) | |
| }; | |
| ({ $( $k:tt : $v:tt ),* }) => { | |
| Json::Object(Box::new( | |
| vec![ | |
| $( ($k.to_string(), json!($v)) ),* | |
| ].into_iter().collect() | |
| )) | |
| }; | |
| ( $other:tt ) => { | |
| Json::from($other) | |
| } | |
| } | |
| fn main() { | |
| let js1 = Json::Array(vec![ | |
| Json::Boolean(true), | |
| Json::Boolean(false), | |
| Json::String("hello".to_string()), | |
| Json::Object(Box::new( | |
| vec![( | |
| "a".to_string(), | |
| Json::Object(Box::new( | |
| vec![( | |
| "b".to_string(), | |
| Json::Array(vec![Json::Null, Json::Number(90.09 as f64)]), | |
| )].into_iter().collect(), | |
| )), | |
| )].into_iter().collect(), | |
| )), | |
| ]); | |
| println!("{:?}", js1); | |
| let js2 = json!([ | |
| true, | |
| false, | |
| "hello", | |
| { "a": { "b": [null, 90.09] } } | |
| ]); | |
| println!("{:?}", js2); | |
| } | |
| #![allow(dead_code, unused)] | |
| use dgraph::{make_dgraph, Dgraph, Request}; | |
| use serde_derive::{Deserialize, Serialize}; | |
| use serde_json::Value; | |
| fn user_type() -> String { | |
| "User".to_string() | |
| } | |
| #[derive(Debug, Default, Serialize, Deserialize)] | |
| struct User { | |
| uid: Option<String>, | |
| name: String, | |
| age: Option<u8>, | |
| friends: Option<Vec<User>>, | |
| #[serde(rename = "dgraph.type")] | |
| #[serde(default = "user_type")] | |
| dgraph_type: String, | |
| } | |
| fn drop_all(dg: &Dgraph) { | |
| let op_clean = dgraph::Operation { | |
| drop_all: true, | |
| ..Default::default() | |
| }; | |
| dg.alter(&op_clean).expect("drop schema"); | |
| } | |
| fn set_schema(dg: &Dgraph) { | |
| let op_schema = dgraph::Operation { | |
| schema: r#" | |
| type User { | |
| name | |
| age | |
| friends | |
| } | |
| name: string @index(exact, term) . | |
| age: int . | |
| friends: [uid] @reverse . | |
| "# | |
| .to_string(), | |
| ..Default::default() | |
| }; | |
| dg.alter(&op_schema).expect("set schema"); | |
| } | |
| fn insert(dg: &Dgraph, user: User) -> String { | |
| let mut mutation = dgraph::Mutation::default(); | |
| mutation.set_set_json(serde_json::to_vec(&user).expect("invalid json")); | |
| let mut txn = dg.new_txn(); | |
| let assigned = txn.mutate(mutation).expect("failed to create data"); | |
| txn.commit().expect("failed to commit mutation"); | |
| let mut uid: String = "".to_string(); | |
| for (_, v) in assigned.uids.iter() { | |
| uid = v.to_string(); | |
| } | |
| uid | |
| } | |
| macro_rules! jin { | |
| [ $j:expr; $( $e:expr ),+ ] => ( | |
| (|| { | |
| let res = $j$(.get($e)?)+; | |
| Some(res) | |
| })(); | |
| ); | |
| } | |
| fn main() { | |
| let dg = make_dgraph!(dgraph::new_dgraph_client("localhost:9080")); | |
| // set_schema(&dg); | |
| let query = r#" | |
| { | |
| query(func: eq(name, "Marcella")) { | |
| uid | |
| name | |
| age | |
| friends (orderasc: age) @filter(le(age, "30")) @facets(related) { | |
| uid | |
| name | |
| age | |
| } | |
| ~friends { | |
| uid | |
| name | |
| age | |
| } | |
| } | |
| } | |
| "# | |
| .to_string(); | |
| let resp = dg.new_readonly_txn().query(query).expect("query"); | |
| let j: Value = serde_json::from_slice(&resp.json).expect("parsing"); | |
| let p = jin![j; "query", 0, "friends", 0, "name"]; | |
| println!( | |
| "{:?}", | |
| match p { | |
| Some(v) => v, | |
| None => &Value::Null, | |
| } | |
| ); | |
| } | |
| #[cfg(test)] | |
| mod tests { | |
| use super::*; | |
| #[test] | |
| fn drop_db() { | |
| let dg = make_dgraph!(dgraph::new_dgraph_client("localhost:9080")); | |
| // drop_all(&dg); | |
| } | |
| } |
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