Disallow table redefinitions

1 files changed, 18 insertions, 2 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 0196fbc..547c407 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -75,8 +75,24 @@ pub enum Value {
 /// Type representing a TOML array, payload of the Value::Array variant
 pub type Array = Vec<Value>;
 
+// The bool field flag is used during parsing and construction.
+// Is true if the given table was explicitly defined, false otherwise
+// e.g. in a toml document: `[a.b] foo = "bar"`, Table `a` would be false,
+// where table `b` (contained inside `a`) would be true.
 /// Type representing a TOML table, payload of the Value::Table variant
-pub type Table = BTreeMap<string::String, Value>;
+#[derive(Debug, Clone)]
+pub struct Table (pub BTreeMap<string::String, Value>, bool);
+impl Table {
+    /// Creates new TOML table
+    pub fn new(map: BTreeMap<string::String, Value>) -> Table {
+        Table(map, false)
+    }
+}
+impl PartialEq for Table {
+    fn eq(&self, other: &Table) -> bool {
+        self.0.eq(&other.0)
+    }
+}
 
 impl Value {
     /// Tests whether this and another value have the same type.
@@ -182,7 +198,7 @@ impl Value {
         let mut cur_value = self;
         for key in path.split('.') {
             match cur_value {
-                &Value::Table(ref hm) => {
+                &Value::Table(Table(ref hm, _)) => {
                     match hm.get(key) {
                         Some(v) => cur_value = v,
                         None => return None