Add Value::to_string{,pretty} methods that preserve structs

Author: cswinter

src/de/mod.rs

@@ -1,7 +1,6 @@
 /// Deserialization module.
 pub use crate::error::{Error, ErrorCode, Result};
 pub use crate::parse::Position;
-use crate::{Map, Value};
 
 use serde::de::{self, DeserializeSeed, Deserializer as SerdeError, Visitor};
 use std::cell::RefCell;

src/error.rs

@@ -106,7 +106,6 @@ impl fmt::Display for ErrorCode {
             ErrorCode::UnderscoreAtBeginning => f.write_str("Found underscore at the beginning"),
             ErrorCode::UnexpectedByte(_) => f.write_str("Unexpected byte"),
             ErrorCode::TrailingCharacters => f.write_str("Non-whitespace trailing characters"),
-            _ => f.write_str("Unknown ErrorCode"),
         }
     }
 }

src/ser/mod.rs

@@ -1,6 +1,7 @@
 use serde::{ser, Deserialize, Serialize};
 use std::io;
 
+use crate::Value;
 use crate::{
     error::{Error, Result},
     extensions::Extensions,
@@ -56,6 +57,22 @@ where
     Ok(String::from_utf8(s.output).expect("Ron should be utf-8"))
 }
 
+impl Value {
+    pub fn to_string(&self) -> Result<String> {
+        let buf = Vec::new();
+        let mut s = Serializer::new(buf, None)?;
+        self.enhanced_serialize(&mut s)?;
+        Ok(String::from_utf8(s.output).expect("Ron should be utf-8"))
+    }
+
+    pub fn to_string_pretty(&self, config: PrettyConfig) -> Result<String> {
+        let buf = Vec::new();
+        let mut s = Serializer::new(buf, Some(config))?;
+        self.enhanced_serialize(&mut s)?;
+        Ok(String::from_utf8(s.output).expect("Ron should be utf-8"))
+    }
+}
+
 /// Pretty serializer state
 struct Pretty {
     indent: usize,
@@ -86,7 +103,7 @@ pub struct PrettyConfig {
     /// Indentation string
     #[serde(default = "default_indentor")]
     pub indentor: String,
-    // Whether to emit struct names
+    /// Whether to emit struct names
     #[serde(default = "default_struct_names")]
     pub struct_names: bool,
     /// Separate tuple members with indentation
@@ -368,6 +385,21 @@ impl<W: io::Write> Serializer<W> {
             .map(|(pc, _)| pc.struct_names)
             .unwrap_or(false)
     }
+
+    fn serialize_struct_dyn<'b>(&mut self, name: &'b str, len: usize) -> Result<Compound<W>> {
+        if self.struct_names() {
+            self.write_identifier(name)?;
+        }
+        self.output.write_all(b"(")?;
+
+        self.is_empty = Some(len == 0);
+        self.start_indent()?;
+
+        Ok(Compound {
+            ser: self,
+            state: State::First,
+        })
+    }
 }
 
 impl<'a, W: io::Write> ser::Serializer for &'a mut Serializer<W> {
@@ -631,18 +663,7 @@ impl<'a, W: io::Write> ser::Serializer for &'a mut Serializer<W> {
     }
 
     fn serialize_struct(self, name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
-        if self.struct_names() {
-            self.write_identifier(name)?;
-        }
-        self.output.write_all(b"(")?;
-
-        self.is_empty = Some(len == 0);
-        self.start_indent()?;
-
-        Ok(Compound {
-            ser: self,
-            state: State::First,
-        })
+        self.serialize_struct_dyn(name, len)
     }
 
     fn serialize_struct_variant(
@@ -866,6 +887,33 @@ impl<'a, W: io::Write> ser::SerializeMap for Compound<'a, W> {
     }
 }
 
+impl<'a, W: io::Write> Compound<'a, W> {
+    fn serialize_field_dyn(&mut self, key: &str, value: &Value) -> Result<()> {
+        if let State::First = self.state {
+            self.state = State::Rest;
+        } else {
+            self.ser.output.write_all(b",")?;
+
+            if let Some((ref config, ref pretty)) = self.ser.pretty {
+                if pretty.indent <= config.depth_limit {
+                    self.ser.output.write_all(config.new_line.as_bytes())?;
+                }
+            }
+        }
+        self.ser.indent()?;
+        self.ser.write_identifier(key)?;
+        self.ser.output.write_all(b":")?;
+
+        if self.ser.is_pretty() {
+            self.ser.output.write_all(b" ")?;
+        }
+
+        value.serialize(&mut *self.ser)?;
+
+        Ok(())
+    }
+}
+
 impl<'a, W: io::Write> ser::SerializeStruct for Compound<'a, W> {
     type Error = Error;
     type Ok = ();

src/ser/tests.rs

@@ -1,4 +1,7 @@
 use super::to_string;
+use crate::ser::PrettyConfig;
+use crate::value::Struct;
+use crate::{Number, Value};
 use serde::Serialize;
 
 #[derive(Serialize)]
@@ -144,3 +147,21 @@ fn rename() {
     assert_eq!(to_string(&Foo::D2).unwrap(), "r#2d");
     assert_eq!(to_string(&Foo::TriangleList).unwrap(), "r#triangle-list");
 }
+
+#[test]
+fn test_value_to_string() {
+    assert_eq!(
+        Value::Struct(Struct {
+            name: Some("Point".to_owned()),
+            fields: [
+                ("x".to_owned(), Value::Number(Number::from(16.3))),
+                ("y".to_owned(), Value::Number(Number::from(3.3))),
+            ]
+            .iter()
+            .cloned()
+            .collect()
+        })
+        .to_string_pretty(PrettyConfig::default().struct_names(true)),
+        Ok("Point(\n    x: 16.3,\n    y: 3.3,\n)".to_string())
+    )
+}

src/ser/value.rs

@@ -1,6 +1,9 @@
-use serde::ser::{Serialize, Serializer};
+use std::io;
+
+use serde::ser::{Serialize, SerializeMap, SerializeSeq, SerializeStruct, Serializer};
 
 use crate::value::{Number, Value};
+use crate::{Error, Map};
 
 impl Serialize for Value {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -11,7 +14,14 @@ impl Serialize for Value {
             Value::Bool(b) => serializer.serialize_bool(b),
             Value::Char(c) => serializer.serialize_char(c),
             Value::Map(ref m) => Serialize::serialize(m, serializer),
-            Value::Struct(ref s) => Serialize::serialize(s, serializer),
+            Value::Struct(ref s) => Serialize::serialize(
+                &Map(s
+                    .fields
+                    .iter()
+                    .map(|(k, v)| (Value::String(k.clone()), v.clone()))
+                    .collect()),
+                serializer,
+            ),
             Value::Number(Number::Float(ref f)) => serializer.serialize_f64(f.get()),
             Value::Number(Number::Integer(i)) => serializer.serialize_i64(i),
             Value::Option(Some(ref o)) => serializer.serialize_some(o.as_ref()),
@@ -22,3 +32,43 @@ impl Serialize for Value {
         }
     }
 }
+
+impl Value {
+    pub fn enhanced_serialize<W: io::Write>(
+        &self,
+        serializer: &mut crate::ser::Serializer<W>,
+    ) -> Result<(), Error> {
+        match *self {
+            Value::Bool(b) => serializer.serialize_bool(b),
+            Value::Char(c) => serializer.serialize_char(c),
+            Value::Map(ref m) => {
+                let mut map = serializer.serialize_map(Some(m.len()))?;
+                for (k, v) in m.iter() {
+                    map.serialize_entry(k, v)?;
+                }
+                SerializeMap::end(map)
+            }
+            Value::Struct(ref s) => {
+                let mut c = serializer
+                    .serialize_struct_dyn(s.name.as_deref().unwrap_or(""), s.fields.len())?;
+                for (field, value) in s.iter() {
+                    c.serialize_field_dyn(field.as_ref(), value)?;
+                }
+                SerializeStruct::end(c)
+            }
+            Value::Number(Number::Float(ref f)) => serializer.serialize_f64(f.get()),
+            Value::Number(Number::Integer(i)) => serializer.serialize_i64(i),
+            Value::Option(Some(ref o)) => serializer.serialize_some(o.as_ref()),
+            Value::Option(None) => serializer.serialize_none(),
+            Value::String(ref s) => serializer.serialize_str(s),
+            Value::Seq(ref s) => {
+                let mut seq = serializer.serialize_seq(Some(s.len()))?;
+                for v in s.iter() {
+                    seq.serialize_element(v)?;
+                }
+                SerializeSeq::end(seq)
+            }
+            Value::Unit => serializer.serialize_unit(),
+        }
+    }
+}

src/value.rs

@@ -23,7 +23,7 @@ use crate::de::{Error as RonError, Result};
 /// The latter can be used by enabling the `indexmap` feature. This can be used
 /// to preserve the order of the parsed map.
 #[derive(Clone, Debug, Default, Deserialize, Serialize)]
-pub struct Map(MapInner);
+pub struct Map(pub MapInner);
 
 impl Map {
     /// Creates a new, empty `Map`.
@@ -160,8 +160,8 @@ impl Struct {
     }
 
     /// Returns `true` if `self.len() == 0`, `false` otherwise.
-    pub fn is_empty(&self) -> usize {
-        self.fields.len()
+    pub fn is_empty(&self) -> bool {
+        self.fields.is_empty()
     }
 
     /// Inserts a new element, returning the previous element with this `key` if