Extract types into separate files

Also make tables more nice to work with and fix debug printing for cyclic
references.

src/main.rs

@@ -1,88 +1,24 @@
-use std::cell::RefCell;
-use std::collections::HashMap;
-use std::fmt::{self, Debug};
-use std::hash::{Hash, Hasher};
-use std::rc::{Rc, Weak};
+use crate::table::{Table, TableOwner};
 
-struct Table(Weak<RefCell<HashMap<Key, Value>>>);
-
-impl Debug for Table {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0.upgrade() {
-            None => write!(f, "<broken table>"),
-            Some(rc) => {
-                // This may panic if we're not careful?
-                let hash_map = &*rc.borrow();
-                hash_map.fmt(f)
-            }
-        }
-    }
-}
-
-impl PartialEq for Table {
-    fn eq(&self, other: &Self) -> bool {
-        self.0.ptr_eq(&other.0)
-    }
-}
-
-impl Eq for Table {}
-
-impl Hash for Table {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.0.as_ptr().hash(state);
-    }
-}
-
-#[derive(PartialEq, Eq, Hash)]
-enum Key {
-    String(Box<String>),
-    Bool(bool),
-    Int(i64),
-    Table(Table),
-}
-
-impl Debug for Key {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::String(s) => s.fmt(f),
-            Self::Bool(b) => b.fmt(f),
-            Self::Int(i) => i.fmt(f),
-            Self::Table(t) => t.fmt(f),
-        }
-    }
-}
-
-#[derive(PartialEq)]
-enum Value {
-    String(Box<String>),
-    Bool(bool),
-    Int(i64),
-    Table(Table),
-    Float(f64),
-}
-
-impl Debug for Value {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::String(s) => s.fmt(f),
-            Self::Bool(b) => b.fmt(f),
-            Self::Int(i) => i.fmt(f),
-            Self::Table(t) => t.fmt(f),
-            Self::Float(d) => d.fmt(f),
-        }
-    }
-}
+mod table;
+mod values;
 
 fn main() {
     println!("Hello, world!");
 
-    let mut table = HashMap::new();
-    table.insert(
-        Key::String(Box::new("Hello".into())),
-        Value::String(Box::new("World".into())),
-    );
-    let table = Rc::new(RefCell::new(table));
+    let table_owner = TableOwner::new();
 
-    let table_value = Value::Table(Table(Rc::downgrade(&table)));
-    dbg!(table_value);
+    let table = Table::new(&table_owner);
+
+    table.insert("Hello".into(), "World".into());
+    table.insert(1.into(), "Goodbye".into());
+    dbg!(&table);
+
+    table.remove(&0.into());
+    table.remove(&1.into());
+    table.remove(&2.into());
+    dbg!(&table);
+
+    table.insert(true.into(), table.clone().into());
+    dbg!(&table);
 }

src/table.rs

@@ -0,0 +1,70 @@
+use std::cell::RefCell;
+use std::collections::HashMap;
+use std::fmt::{self, Debug};
+use std::hash::{Hash, Hasher};
+use std::rc::{Rc, Weak};
+
+use crate::values::{Key, Value};
+
+pub struct TableOwner(Rc<RefCell<HashMap<Key, Value>>>);
+
+impl TableOwner {
+    pub fn new() -> Self {
+        Self(Rc::new(RefCell::new(HashMap::new())))
+    }
+}
+
+#[derive(Clone)]
+pub struct Table(Weak<RefCell<HashMap<Key, Value>>>);
+
+impl Debug for Table {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let rc = match self.0.upgrade() {
+            Some(rc) => rc,
+            None => return write!(f, "<broken table>"),
+        };
+
+        let hash_map = match rc.try_borrow_mut() {
+            Ok(hash_map) => hash_map,
+            Err(_) => return write!(f, "<cyclic ref>"),
+        };
+
+        hash_map.fmt(f)
+    }
+}
+
+impl PartialEq for Table {
+    fn eq(&self, other: &Self) -> bool {
+        self.0.ptr_eq(&other.0)
+    }
+}
+
+impl Eq for Table {}
+
+impl Hash for Table {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.0.as_ptr().hash(state);
+    }
+}
+
+impl Table {
+    pub fn new(owner: &TableOwner) -> Self {
+        Self(Rc::downgrade(&owner.0))
+    }
+
+    pub fn insert(&self, key: Key, value: Value) {
+        self.0
+            .upgrade()
+            .expect("table owner was deallocated")
+            .borrow_mut()
+            .insert(key, value);
+    }
+
+    pub fn remove(&self, key: &Key) {
+        self.0
+            .upgrade()
+            .expect("table owner was deallocated")
+            .borrow_mut()
+            .remove(key);
+    }
+}

src/values.rs

@@ -0,0 +1,121 @@
+use std::fmt::{self, Debug};
+
+use crate::table::Table;
+
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub enum Key {
+    String(Box<String>),
+    Bool(bool),
+    Int(i64),
+    Table(Table),
+}
+
+impl Debug for Key {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::String(s) => s.fmt(f),
+            Self::Bool(b) => b.fmt(f),
+            Self::Int(i) => i.fmt(f),
+            Self::Table(t) => t.fmt(f),
+        }
+    }
+}
+
+impl From<Box<String>> for Key {
+    fn from(s: Box<String>) -> Self {
+        Self::String(s)
+    }
+}
+
+impl From<String> for Key {
+    fn from(s: String) -> Self {
+        Self::String(Box::new(s))
+    }
+}
+
+impl From<&str> for Key {
+    fn from(s: &str) -> Self {
+        Self::String(Box::new(s.to_string()))
+    }
+}
+
+impl From<bool> for Key {
+    fn from(b: bool) -> Self {
+        Self::Bool(b)
+    }
+}
+
+impl From<i64> for Key {
+    fn from(i: i64) -> Self {
+        Self::Int(i)
+    }
+}
+
+impl From<Table> for Key {
+    fn from(t: Table) -> Self {
+        Self::Table(t)
+    }
+}
+
+#[derive(Clone, PartialEq)]
+pub enum Value {
+    String(Box<String>),
+    Bool(bool),
+    Int(i64),
+    Float(f64),
+    Table(Table),
+}
+
+impl Debug for Value {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::String(s) => s.fmt(f),
+            Self::Bool(b) => b.fmt(f),
+            Self::Int(i) => i.fmt(f),
+            Self::Table(t) => t.fmt(f),
+            Self::Float(d) => d.fmt(f),
+        }
+    }
+}
+
+impl From<Box<String>> for Value {
+    fn from(s: Box<String>) -> Self {
+        Self::String(s)
+    }
+}
+
+impl From<String> for Value {
+    fn from(s: String) -> Self {
+        Self::String(Box::new(s))
+    }
+}
+
+impl From<&str> for Value {
+    fn from(s: &str) -> Self {
+        Self::String(Box::new(s.to_string()))
+    }
+}
+
+impl From<bool> for Value {
+    fn from(b: bool) -> Self {
+        Self::Bool(b)
+    }
+}
+
+impl From<i64> for Value {
+    fn from(i: i64) -> Self {
+        Self::Int(i)
+    }
+}
+
+impl From<f64> for Value {
+    fn from(f: f64) -> Self {
+        Self::Float(f)
+    }
+}
+
+impl From<Table> for Value {
+    fn from(t: Table) -> Self {
+        Self::Table(t)
+    }
+}