mentat/tolstoy/src/datoms.rs

59 lines
1.8 KiB
Rust

// Copyright 2018 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// License at http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
use edn::Keyword;
use crate::TxPart;
use core_traits::{Entid, TypedValue};
/// A primitive query interface geared toward processing bootstrap-like sets of datoms.
pub struct DatomsHelper<'a> {
parts: &'a [TxPart],
}
impl<'a> DatomsHelper<'a> {
pub fn new(parts: &[TxPart]) -> DatomsHelper<'_> {
DatomsHelper { parts }
}
// TODO these are obviously quite inefficient
pub fn e_lookup(&self, e: Keyword) -> Option<Entid> {
// This wraps Keyword (e) in ValueRc (aliased Arc), which is rather expensive.
let kw_e = TypedValue::Keyword(e.into());
for part in self.parts {
if kw_e == part.v && part.added {
return Some(part.e);
}
}
None
}
pub fn ea_lookup(&self, e: Keyword, a: Keyword) -> Option<&TypedValue> {
let e_e = self.e_lookup(e);
let a_e = self.e_lookup(a);
if e_e.is_none() || a_e.is_none() {
return None;
}
let e_e = e_e.unwrap();
let a_e = a_e.unwrap();
for part in self.parts {
if part.e == e_e && part.a == a_e && part.added {
return Some(&part.v);
}
}
None
}
}