From dab7671b07d14599beb7866cc7a510bdacf11b95 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 6 Apr 2021 01:12:41 +0100
Subject: [PATCH] pcaliases: split out

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/global.rs    |  6 -----
 src/lib.rs       |  1 +
 src/pcaliases.rs | 69 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/prelude.rs   |  1 +
 src/shapelib.rs  | 37 --------------------------
 5 files changed, 71 insertions(+), 43 deletions(-)
 create mode 100644 src/pcaliases.rs

diff --git a/src/global.rs b/src/global.rs
index 1910b218..01126f39 100644
--- a/src/global.rs
+++ b/src/global.rs
@@ -1,7 +1,3 @@
-// Copyright 2020-2021 Ian Jackson and contributors to Otter
-// SPDX-License-Identifier: AGPL-3.0-or-later
-// There is NO WARRANTY.
-
 #![allow(clippy::let_and_return)]
 
 use crate::prelude::*;
@@ -70,8 +66,6 @@ pub struct IPlayer { // usual variable: ipl
   pub tz: Timezone,
 }
 
-pub type PieceAliases = BTreeMap<String, Box<dyn PieceSpec>>;
-
 #[derive(Debug,Serialize,Deserialize)]
 pub struct IPiece {
   pub p: IPieceTraitObj,
diff --git a/src/lib.rs b/src/lib.rs
index f2109a9d..73d51a29 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -25,6 +25,7 @@ pub mod mgmtchannel;
 pub mod nwtemplates;
 pub mod occultilks;
 pub mod organise;
+pub mod pcaliases;
 pub mod pcrender;
 pub mod pieces;
 pub mod shapelib;
diff --git a/src/pcaliases.rs b/src/pcaliases.rs
new file mode 100644
index 00000000..5344d40a
--- /dev/null
+++ b/src/pcaliases.rs
@@ -0,0 +1,69 @@
+// Copyright 2020-2021 Ian Jackson and contributors to Otter
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// There is NO WARRANTY.
+
+use crate::prelude::*;
+
+type Fwd = BTreeMap<String, Box<dyn PieceSpec>>;
+
+#[derive(Debug,Default,Serialize,Deserialize)]
+#[serde(transparent)]
+pub struct PieceAliasesSave(Fwd);
+
+#[derive(Debug,Default,Serialize,Deserialize)]
+pub struct PieceAliases {
+  fwd: Fwd,
+}
+
+impl PieceAliases {
+  pub fn remove(&mut self, alias: &str) {
+    self.fwd.remove(alias);
+  }
+
+  pub fn insert(&mut self, alias: String, target: Box<dyn PieceSpec>) {
+    self.fwd.insert(alias, target);
+  }
+
+  pub fn keys(&self) -> impl Iterator<Item=&String> {
+    self.fwd.keys()
+  }
+}
+
+#[derive(Debug,Clone,Serialize,Deserialize)]
+struct Alias {
+  target: String,
+}
+
+impl Alias {
+  #[throws(SpecError)]
+  fn resolve<'a>(&self, pcaliases: &'a PieceAliases) -> &'a dyn PieceSpec {
+    Box::as_ref(
+      pcaliases
+        .fwd
+        .get(&self.target)
+        .ok_or(SpecError::AliasNotFound)?
+    )
+  }
+}
+
+#[typetag::serde]
+impl PieceSpec for Alias {
+  #[throws(SpecError)]
+  fn count(&self, pcaliases: &PieceAliases) -> usize {
+    // passing default() avoids resolving alias chains, so we don't
+    // have to worry about cycles
+    self.resolve(pcaliases)?.count(&default())?
+  }
+  #[throws(SpecError)]
+  fn load(&self, i: usize, gpc: &mut GPiece,
+          pcaliases: &PieceAliases, ir: &InstanceRef)
+          -> PieceSpecLoaded {
+    self.resolve(pcaliases)?.load(i, gpc, &default(), ir)?
+  }
+  #[throws(SpecError)]
+  fn load_occult(&self, pcaliases: &PieceAliases)
+                 -> Box<dyn OccultedPieceTrait> {
+    self.resolve(pcaliases)?.load_occult(&default())?
+  }
+}
+
diff --git a/src/prelude.rs b/src/prelude.rs
index accc5773..dd2d8c79 100644
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -135,6 +135,7 @@ pub use crate::mgmtchannel::*;
 pub use crate::nwtemplates;
 pub use crate::occultilks::*;
 pub use crate::organise;
+pub use crate::pcaliases::*;
 pub use crate::pcrender::*;
 pub use crate::pieces::*;
 pub use crate::shapelib;
diff --git a/src/shapelib.rs b/src/shapelib.rs
index 2419fcb3..00708391 100644
--- a/src/shapelib.rs
+++ b/src/shapelib.rs
@@ -474,43 +474,6 @@ impl Contents {
   }
 }
 
-#[derive(Debug,Clone,Serialize,Deserialize)]
-struct Alias {
-  target: String,
-}
-
-impl Alias {
-  #[throws(SpecError)]
-  fn resolve<'a>(&self, pcaliases: &'a PieceAliases) -> &'a dyn PieceSpec {
-    Box::as_ref(
-      pcaliases
-        .get(&self.target)
-        .ok_or(SpecError::AliasNotFound)?
-    )
-  }
-}
-
-#[typetag::serde]
-impl PieceSpec for Alias {
-  #[throws(SpecError)]
-  fn count(&self, pcaliases: &PieceAliases) -> usize {
-    // passing default() avoids resolving alias chains, so we don't
-    // have to worry about cycles
-    self.resolve(pcaliases)?.count(&default())?
-  }
-  #[throws(SpecError)]
-  fn load(&self, i: usize, gpc: &mut GPiece,
-          pcaliases: &PieceAliases, ir: &InstanceRef)
-          -> PieceSpecLoaded {
-    self.resolve(pcaliases)?.load(i, gpc, &default(), ir)?
-  }
-  #[throws(SpecError)]
-  fn load_occult(&self, pcaliases: &PieceAliases)
-                 -> Box<dyn OccultedPieceTrait> {
-    self.resolve(pcaliases)?.load_occult(&default())?
-  }
-}
-
 #[typetag::serde(name="Lib")]
 impl PieceSpec for ItemSpec {
   #[throws(SpecError)]
-- 
2.30.2