From a85107d39aa1d0d09dd0d4a3633518c9c7fcbd9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kat=20March=C3=A1n?= <kzm@zkat.tech>
Date: Tue, 8 Oct 2024 22:44:00 -0700
Subject: [PATCH] add serde support

wip
---
 Cargo.toml |   3 +-
 src/de.rs  | 235 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs |   5 ++
 src/se.rs  |   1 +
 4 files changed, 243 insertions(+), 1 deletion(-)
 create mode 100644 src/de.rs
 create mode 100644 src/se.rs

diff --git a/Cargo.toml b/Cargo.toml
index e317dd4..66a4812 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@ rust-version = "1.70.0"
 edition = "2021"
 
 [features]
-default = ["span"]
+default = ["span", "serde"]
 span = []
 v1-fallback = ["v1"]
 v1 = ["kdlv1"]
@@ -20,6 +20,7 @@ v1 = ["kdlv1"]
 [dependencies]
 miette = "7.2.0"
 num = "0.4.2"
+serde = { version = "1.0.210", optional = true }
 thiserror = "1.0.40"
 winnow = { version = "0.6.20", features = ["alloc", "unstable-recover"] }
 kdlv1 = { package = "kdl", version = "4.7.0", optional = true }
diff --git a/src/de.rs b/src/de.rs
new file mode 100644
index 0000000..a1a1d06
--- /dev/null
+++ b/src/de.rs
@@ -0,0 +1,235 @@
+use serde::{de, Deserialize};
+use thiserror::Error;
+use winnow::{stream::Recoverable, Located};
+
+use crate::{v2_parser::KdlParseError, KdlParseFailure};
+
+/// serde deserializer for KDL documents
+#[derive(Debug)]
+pub struct Deserializer<'de> {
+    input: Recoverable<Located<&'de str>, KdlParseError>,
+}
+
+impl<'de> Deserializer<'de> {
+    /// Create a new deserializer from a string
+    pub fn from_str(input: &'de str) -> Self {
+        Self {
+            input: Recoverable::new(Located::new(input)),
+        }
+    }
+}
+
+/// Deserialize a type from a KDL string
+pub fn from_str<'a, T>(input: &'a str) -> Result<T, KdlParseFailure>
+where
+    T: Deserialize<'a>,
+{
+}
+
+#[derive(Debug, Error)]
+struct DeError(String);
+
+impl std::fmt::Display for DeError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl de::Error for DeError {
+    fn custom<T: std::fmt::Display>(msg: T) -> Self {
+        DeError(msg.to_string())
+    }
+}
+
+struct KdlVisitor;
+
+impl<'de> de::Visitor<'de> for KdlVisitor {
+    type Value = ();
+
+    fn expecting<'a>(&self, formatter: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {
+        write!(formatter, "a KDL value")
+    }
+
+    fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+    where
+        A: de::MapAccess<'de>,
+    {
+        while let Some(key) = map.next_key()? {
+            match key {
+                "type" => {
+                    let value = map.next_value::<String>()?;
+                    println!("type: {}", value);
+                }
+                "value" => {
+                    let value = map.next_value::<String>()?;
+                    println!("value: {}", value);
+                }
+                _ => {
+                    map.next_value::<serde::de::IgnoredAny>()?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
+    type Error = DeError;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_map(visitor)
+    }
+
+    fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_unit_struct<V>(
+        self,
+        name: &'static str,
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_newtype_struct<V>(
+        self,
+        name: &'static str,
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_tuple_struct<V>(
+        self,
+        name: &'static str,
+        len: usize,
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_struct<V>(
+        self,
+        name: &'static str,
+        fields: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_enum<V>(
+        self,
+        name: &'static str,
+        variants: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+
+    fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        todo!()
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index e3eff78..000418c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -208,3 +208,8 @@ mod node;
 mod value;
 
 mod v2_parser;
+
+#[cfg(feature = "serde")]
+pub mod de;
+#[cfg(feature = "serde")]
+pub mod se;
diff --git a/src/se.rs b/src/se.rs
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/se.rs
@@ -0,0 +1 @@
+