From 38c8b2d911cea46a98387ea39ef0d74383cf2a4a Mon Sep 17 00:00:00 2001
From: Graham Esau <gesau@hotmail.co.uk>
Date: Sun, 4 Aug 2019 20:43:02 +0100
Subject: [PATCH] Tuples!

---
 schemars/src/make_schema.rs | 50 +++++++++++++++++++++++++++++++++++--
 schemars/src/schema.rs      | 22 ++++------------
 2 files changed, 53 insertions(+), 19 deletions(-)

diff --git a/schemars/src/make_schema.rs b/schemars/src/make_schema.rs
index e53c376..1a210a6 100644
--- a/schemars/src/make_schema.rs
+++ b/schemars/src/make_schema.rs
@@ -128,7 +128,7 @@ macro_rules! array_impls {
                     extensions.insert("maxItems".to_owned(), json!($len));
                     SchemaObject {
                         instance_type: Some(InstanceType::Array.into()),
-                        items: Some(Box::from(gen.subschema_for::<T>())),
+                        items: Some(gen.subschema_for::<T>().into()),
                         extensions,
                         ..Default::default()
                     }.into()
@@ -145,6 +145,52 @@ array_impls! {
     31 32
 }
 
+////////// TUPLES //////////
+
+macro_rules! tuple_impls {
+    ($($len:expr => ($($name:ident)+))+) => {
+        $(
+            impl<$($name: MakeSchema),+> MakeSchema for ($($name,)+) {
+                no_ref_schema!();
+
+                fn make_schema(gen: &mut SchemaGenerator) -> Schema {
+                    let mut extensions = Map::new();
+                    extensions.insert("minItems".to_owned(), json!($len));
+                    extensions.insert("maxItems".to_owned(), json!($len));
+                    let items = vec![
+                        $(gen.subschema_for::<$name>()),+
+                    ];
+                    SchemaObject {
+                        instance_type: Some(InstanceType::Array.into()),
+                        items: Some(items.into()),
+                        extensions,
+                        ..Default::default()
+                    }.into()
+                }
+            }
+        )+
+    }
+}
+
+tuple_impls! {
+    1 => (T0)
+    2 => (T0 T1)
+    3 => (T0 T1 T2)
+    4 => (T0 T1 T2 T3)
+    5 => (T0 T1 T2 T3 T4)
+    6 => (T0 T1 T2 T3 T4 T5)
+    7 => (T0 T1 T2 T3 T4 T5 T6)
+    8 => (T0 T1 T2 T3 T4 T5 T6 T7)
+    9 => (T0 T1 T2 T3 T4 T5 T6 T7 T8)
+    10 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9)
+    11 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10)
+    12 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11)
+    13 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12)
+    14 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13)
+    15 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14)
+    16 => (T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15)
+}
+
 ////////// SEQUENCES /////////
 
 macro_rules! seq_impl {
@@ -159,7 +205,7 @@ macro_rules! seq_impl {
             {
                 SchemaObject {
                     instance_type: Some(InstanceType::Array.into()),
-                    items: Some(Box::from(gen.subschema_for::<T>())),
+                    items: Some(gen.subschema_for::<T>().into()),
                     ..Default::default()
                 }.into()
             }
diff --git a/schemars/src/schema.rs b/schemars/src/schema.rs
index 120ef76..cc5b3b9 100644
--- a/schemars/src/schema.rs
+++ b/schemars/src/schema.rs
@@ -52,7 +52,7 @@ pub struct SchemaObject {
     #[serde(rename = "enum", skip_serializing_if = "Option::is_none")]
     pub enum_values: Option<Vec<Value>>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub items: Option<Box<Schema>>,
+    pub items: Option<SingleOrVec<Schema>>,
     #[serde(skip_serializing_if = "Map::is_empty")]
     pub properties: Map<String, Schema>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -86,30 +86,18 @@ pub enum InstanceType {
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 #[serde(untagged)]
 pub enum SingleOrVec<T> {
-    Single(T),
+    Single(Box<T>),
     Vec(Vec<T>),
 }
 
 impl<T> From<T> for SingleOrVec<T> {
     fn from(single: T) -> Self {
-        SingleOrVec::Single(single)
+        SingleOrVec::Single(Box::new(single))
     }
 }
 
 impl<T> From<Vec<T>> for SingleOrVec<T> {
-    fn from(mut vec: Vec<T>) -> Self {
-        match vec.len() {
-            1 => SingleOrVec::Single(vec.remove(0)),
-            _ => SingleOrVec::Vec(vec),
-        }
-    }
-}
-
-impl<T> Into<Vec<T>> for SingleOrVec<T> {
-    fn into(self) -> Vec<T> {
-        match self {
-            SingleOrVec::Single(s) => vec![s],
-            SingleOrVec::Vec(v) => v,
-        }
+    fn from(vec: Vec<T>) -> Self {
+        SingleOrVec::Vec(vec)
     }
 }