1 files changed, 160 insertions, 0 deletions
diff --git a/src/de/table_enum.rs b/src/de/table_enum.rs
new file mode 100644
index 0000000..197ad6e
--- /dev/null
+++ b/src/de/table_enum.rs
@@ -0,0 +1,160 @@
+use crate::de::Error;
+
+/// Deserializes table values into enum variants.
+pub(crate) struct TableEnumDeserializer {
+    value: crate::Item,
+}
+
+impl TableEnumDeserializer {
+    pub(crate) fn new(value: crate::Item) -> Self {
+        TableEnumDeserializer { value }
+    }
+}
+
+impl<'de> serde::de::VariantAccess<'de> for TableEnumDeserializer {
+    type Error = Error;
+
+    fn unit_variant(self) -> Result<(), Self::Error> {
+        match self.value {
+            crate::Item::Table(values) => {
+                if values.is_empty() {
+                    Ok(())
+                } else {
+                    Err(Error::custom("expected empty table", values.span()))
+                }
+            }
+            crate::Item::Value(crate::Value::InlineTable(values)) => {
+                if values.is_empty() {
+                    Ok(())
+                } else {
+                    Err(Error::custom("expected empty table", values.span()))
+                }
+            }
+            e => Err(Error::custom(
+                format!("expected table, found {}", e.type_name()),
+                e.span(),
+            )),
+        }
+    }
+
+    fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Self::Error>
+    where
+        T: serde::de::DeserializeSeed<'de>,
+    {
+        seed.deserialize(super::ValueDeserializer::new(self.value))
+    }
+
+    fn tuple_variant<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        match self.value {
+            crate::Item::Table(values) => {
+                let values_span = values.span();
+                let tuple_values = values
+                    .items
+                    .into_iter()
+                    .enumerate()
+                    .map(
+                        |(index, (_, value))| match value.key.get().parse::<usize>() {
+                            Ok(key_index) if key_index == index => Ok(value.value),
+                            Ok(_) | Err(_) => Err(Error::custom(
+                                format!(
+                                    "expected table key `{}`, but was `{}`",
+                                    index,
+                                    value.key.get()
+                                ),
+                                value.key.span(),
+                            )),
+                        },
+                    )
+                    // Fold all values into a `Vec`, or return the first error.
+                    .fold(Ok(Vec::with_capacity(len)), |result, value_result| {
+                        result.and_then(move |mut tuple_values| match value_result {
+                            Ok(value) => {
+                                tuple_values.push(value);
+                                Ok(tuple_values)
+                            }
+                            // `Result<de::Value, Self::Error>` to `Result<Vec<_>, Self::Error>`
+                            Err(e) => Err(e),
+                        })
+                    })?;
+
+                if tuple_values.len() == len {
+                    serde::de::Deserializer::deserialize_seq(
+                        super::ArrayDeserializer::new(tuple_values, values_span),
+                        visitor,
+                    )
+                } else {
+                    Err(Error::custom(
+                        format!("expected tuple with length {}", len),
+                        values_span,
+                    ))
+                }
+            }
+            crate::Item::Value(crate::Value::InlineTable(values)) => {
+                let values_span = values.span();
+                let tuple_values = values
+                    .items
+                    .into_iter()
+                    .enumerate()
+                    .map(
+                        |(index, (_, value))| match value.key.get().parse::<usize>() {
+                            Ok(key_index) if key_index == index => Ok(value.value),
+                            Ok(_) | Err(_) => Err(Error::custom(
+                                format!(
+                                    "expected table key `{}`, but was `{}`",
+                                    index,
+                                    value.key.get()
+                                ),
+                                value.key.span(),
+                            )),
+                        },
+                    )
+                    // Fold all values into a `Vec`, or return the first error.
+                    .fold(Ok(Vec::with_capacity(len)), |result, value_result| {
+                        result.and_then(move |mut tuple_values| match value_result {
+                            Ok(value) => {
+                                tuple_values.push(value);
+                                Ok(tuple_values)
+                            }
+                            // `Result<de::Value, Self::Error>` to `Result<Vec<_>, Self::Error>`
+                            Err(e) => Err(e),
+                        })
+                    })?;
+
+                if tuple_values.len() == len {
+                    serde::de::Deserializer::deserialize_seq(
+                        super::ArrayDeserializer::new(tuple_values, values_span),
+                        visitor,
+                    )
+                } else {
+                    Err(Error::custom(
+                        format!("expected tuple with length {}", len),
+                        values_span,
+                    ))
+                }
+            }
+            e => Err(Error::custom(
+                format!("expected table, found {}", e.type_name()),
+                e.span(),
+            )),
+        }
+    }
+
+    fn struct_variant<V>(
+        self,
+        fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: serde::de::Visitor<'de>,
+    {
+        serde::de::Deserializer::deserialize_struct(
+            super::ValueDeserializer::new(self.value).with_struct_key_validation(),
+            "", // TODO: this should be the variant name
+            fields,
+            visitor,
+        )
+    }
+}