dedup dependencies

macros/src/deps.rs

@@ -1,54 +1,84 @@
+use std::collections::HashSet;
+
 use proc_macro2::TokenStream;
 use quote::{quote, ToTokens};
 use syn::{Path, Type};
 
 pub struct Dependencies {
-    dependencies: Vec<TokenStream>,
     crate_rename: Path,
+    dependencies: HashSet<Operation>,
     pub types: Vec<Type>,
 }
 
+#[derive(Hash, Eq, PartialEq)]
+enum Operation {
+    ExtendByDependencyTypes { crate_rename: Path, ty: Type },
+    ExtendGenerics { crate_rename: Path, ty: Type },
+    PushType(Type),
+}
+
 impl Dependencies {
     pub fn new(crate_rename: Path) -> Self {
         Self {
-            dependencies: Vec::default(),
+            dependencies: HashSet::default(),
             crate_rename,
             types: Vec::default(),
         }
     }
+
     /// Adds all dependencies from the given type
     pub fn append_from(&mut self, ty: &Type) {
-        let crate_rename = &self.crate_rename;
         self.dependencies
-            .push(quote![.extend(<#ty as #crate_rename::TS>::dependency_types())]);
+            .insert(Operation::ExtendByDependencyTypes {
+                crate_rename: self.crate_rename.clone(),
+                ty: ty.clone(),
+            });
+
         self.types.push(ty.clone());
     }
 
     /// Adds the given type.
     pub fn push(&mut self, ty: &Type) {
-        let crate_rename = &self.crate_rename;
-        self.dependencies.push(quote![.push::<#ty>()]);
-        self.dependencies.push(quote![
-            .extend(<#ty as #crate_rename::TS>::generics())
-        ]);
+        self.dependencies.insert(Operation::PushType(ty.clone()));
+        self.dependencies.insert(Operation::ExtendGenerics {
+            crate_rename: self.crate_rename.clone(),
+            ty: ty.clone(),
+        });
         self.types.push(ty.clone());
     }
 
     pub fn append(&mut self, mut other: Dependencies) {
-        if !other.dependencies.is_empty() {
-            self.dependencies.push(quote![.extend(#other)]);
+        self.dependencies.extend(other.dependencies);
+
+        if !other.types.is_empty() {
+            self.types.append(&mut other.types);
         }
-        self.types.append(&mut other.types);
     }
 }
 
 impl ToTokens for Dependencies {
     fn to_tokens(&self, tokens: &mut TokenStream) {
         let crate_rename = &self.crate_rename;
-        let lines = &self.dependencies;
+
+        let lines = self
+            .dependencies
+            .iter()
+            .map(|operation| match operation {
+                Operation::PushType(ty) => quote![.push::<#ty>()],
+                Operation::ExtendByDependencyTypes { crate_rename, ty } => {
+                    quote![.extend(<#ty as #crate_rename::TS>::dependency_types())]
+                }
+                Operation::ExtendGenerics { crate_rename, ty } => {
+                    quote![
+                        .extend(<#ty as #crate_rename::TS>::generics())
+                    ]
+                }
+            })
+            .collect::<Vec<_>>();
+
         tokens.extend(quote![{
             use #crate_rename::typelist::TypeList;
             ()#(#lines)*
-        }])
+        }]);
     }
 }