From f0ddea821cd214254ce201d29410c25b61940f9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Renault?= <clement@meilisearch.com>
Date: Fri, 19 Feb 2021 15:14:00 +0100
Subject: [PATCH] Introduce the Typo criterion

---
 milli/src/search/criteria/mod.rs | 34 ++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 milli/src/search/criteria/mod.rs

diff --git a/milli/src/search/criteria/mod.rs b/milli/src/search/criteria/mod.rs
new file mode 100644
index 000000000..4cc4512d7
--- /dev/null
+++ b/milli/src/search/criteria/mod.rs
@@ -0,0 +1,34 @@
+use crate::Index;
+
+use roaring::RoaringBitmap;
+
+use super::query_tree::Operation;
+
+pub mod typo;
+
+pub trait Criterion {
+    fn next(&mut self) -> anyhow::Result<Option<(Option<Operation>, RoaringBitmap)>>;
+}
+
+/// Either a set of candidates that defines the candidates
+/// that are allowed to be returned,
+/// or the candidates that must never be returned.
+enum Candidates {
+    Allowed(RoaringBitmap),
+    Forbidden(RoaringBitmap)
+}
+
+impl Candidates {
+    fn into_inner(self) -> RoaringBitmap {
+        match self {
+            Self::Allowed(inner) => inner,
+            Self::Forbidden(inner) => inner,
+        }
+    }
+}
+
+impl Default for Candidates {
+    fn default() -> Self {
+        Self::Forbidden(RoaringBitmap::new())
+    }
+}