From 3ae5ba09fdc0b111f3c6200da2c8c1e2a9c6c30f Mon Sep 17 00:00:00 2001
From: Nathan Sobo <nathan@zed.dev>
Date: Fri, 22 Oct 2021 12:46:02 -0600
Subject: [PATCH] Implement TryFrom<proto::SelectionSet> on SelectionSet

More prep work for changing the selection set representation.
---
 crates/buffer/src/lib.rs       | 48 ++++++-----------------------
 crates/buffer/src/selection.rs | 55 +++++++++++++++++++++++++++++++---
 2 files changed, 60 insertions(+), 43 deletions(-)

diff --git a/crates/buffer/src/lib.rs b/crates/buffer/src/lib.rs
index 4511531cf4..6deaf228a1 100644
--- a/crates/buffer/src/lib.rs
+++ b/crates/buffer/src/lib.rs
@@ -20,7 +20,7 @@ use rpc::proto;
 pub use selection::*;
 use std::{
     cmp,
-    convert::{TryFrom, TryInto},
+    convert::TryFrom,
     iter::Iterator,
     ops::Range,
     str,
@@ -486,20 +486,8 @@ impl Buffer {
             .selections
             .into_iter()
             .map(|set| {
-                let set_id = clock::Lamport {
-                    replica_id: set.replica_id as ReplicaId,
-                    value: set.lamport_timestamp,
-                };
-                let selections: Vec<Selection> = set
-                    .selections
-                    .into_iter()
-                    .map(TryFrom::try_from)
-                    .collect::<Result<_, _>>()?;
-                let set = SelectionSet {
-                    selections: Arc::from(selections),
-                    active: set.is_active,
-                };
-                Result::<_, anyhow::Error>::Ok((set_id, set))
+                let set = SelectionSet::try_from(set)?;
+                Result::<_, anyhow::Error>::Ok((set.id, set))
             })
             .collect::<Result<_, _>>()?;
         Ok(buffer)
@@ -859,6 +847,7 @@ impl Buffer {
                     self.selections.insert(
                         set_id,
                         SelectionSet {
+                            id: set_id,
                             selections,
                             active: false,
                         },
@@ -1290,18 +1279,19 @@ impl Buffer {
 
     pub fn add_selection_set(&mut self, selections: impl Into<Arc<[Selection]>>) -> Operation {
         let selections = selections.into();
-        let lamport_timestamp = self.lamport_clock.tick();
+        let set_id = self.lamport_clock.tick();
         self.selections.insert(
-            lamport_timestamp,
+            set_id,
             SelectionSet {
+                id: set_id,
                 selections: selections.clone(),
                 active: false,
             },
         );
         Operation::UpdateSelections {
-            set_id: lamport_timestamp,
+            set_id,
             selections,
-            lamport_timestamp,
+            lamport_timestamp: set_id,
         }
     }
 
@@ -2390,26 +2380,6 @@ impl TryFrom<proto::Anchor> for Anchor {
     }
 }
 
-impl TryFrom<proto::Selection> for Selection {
-    type Error = anyhow::Error;
-
-    fn try_from(selection: proto::Selection) -> Result<Self, Self::Error> {
-        Ok(Selection {
-            id: selection.id as usize,
-            start: selection
-                .start
-                .ok_or_else(|| anyhow!("missing selection start"))?
-                .try_into()?,
-            end: selection
-                .end
-                .ok_or_else(|| anyhow!("missing selection end"))?
-                .try_into()?,
-            reversed: selection.reversed,
-            goal: SelectionGoal::None,
-        })
-    }
-}
-
 pub trait ToOffset {
     fn to_offset<'a>(&self, content: impl Into<Content<'a>>) -> usize;
 }
diff --git a/crates/buffer/src/selection.rs b/crates/buffer/src/selection.rs
index df0834b67f..589746803b 100644
--- a/crates/buffer/src/selection.rs
+++ b/crates/buffer/src/selection.rs
@@ -1,7 +1,13 @@
-use rpc::proto;
-
 use crate::{Anchor, Buffer, Point, ToOffset as _, ToPoint as _};
-use std::{cmp::Ordering, mem, ops::Range, sync::Arc};
+use anyhow::anyhow;
+use rpc::proto;
+use std::{
+    cmp::Ordering,
+    convert::{TryFrom, TryInto},
+    mem,
+    ops::Range,
+    sync::Arc,
+};
 
 pub type SelectionSetId = clock::Lamport;
 pub type SelectionsVersion = usize;
@@ -24,8 +30,9 @@ pub struct Selection {
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct SelectionSet {
-    pub selections: Arc<[Selection]>,
+    pub id: SelectionSetId,
     pub active: bool,
+    pub selections: Arc<[Selection]>,
 }
 
 impl Selection {
@@ -92,3 +99,43 @@ impl<'a> Into<proto::Selection> for &'a Selection {
         }
     }
 }
+
+impl TryFrom<proto::Selection> for Selection {
+    type Error = anyhow::Error;
+
+    fn try_from(selection: proto::Selection) -> Result<Self, Self::Error> {
+        Ok(Selection {
+            id: selection.id as usize,
+            start: selection
+                .start
+                .ok_or_else(|| anyhow!("missing selection start"))?
+                .try_into()?,
+            end: selection
+                .end
+                .ok_or_else(|| anyhow!("missing selection end"))?
+                .try_into()?,
+            reversed: selection.reversed,
+            goal: SelectionGoal::None,
+        })
+    }
+}
+
+impl TryFrom<proto::SelectionSet> for SelectionSet {
+    type Error = anyhow::Error;
+
+    fn try_from(set: proto::SelectionSet) -> Result<Self, Self::Error> {
+        Ok(Self {
+            id: clock::Lamport {
+                replica_id: set.replica_id as u16,
+                value: set.lamport_timestamp,
+            },
+            active: set.is_active,
+            selections: Arc::from(
+                set.selections
+                    .into_iter()
+                    .map(TryInto::try_into)
+                    .collect::<Result<Vec<Selection>, _>>()?,
+            ),
+        })
+    }
+}