material parser

1 files changed, 16 insertions, 0 deletions

diff --git a/src/object/parser.rs b/src/object/parser.rs
index 5879e9a..d80e38c 100644
--- a/src/object/parser.rs
+++ b/src/object/parser.rs
@@ -90,3 +90,19 @@ impl Value {
         self.as_class("vector").ok()?.remove("Array")?.as_array()
     }
 }
+
+impl<K: FromValue + Ord, V: FromValue> FromValue for BTreeMap<K, V> {
+    fn from_value(v: Value) -> Result<Self> {
+        v.as_class("map")?
+            .remove("Array")
+            .ok_or(anyhow!("map is missing Array field"))?
+            .as_array()
+            .ok_or(anyhow!("map Array field is not an array"))?
+            .into_iter()
+            .map(|e| {
+                let mut fields = e.as_class("pair")?;
+                Ok((fields.field("first")?, fields.field("second")?))
+            })
+            .collect::<Result<BTreeMap<_, _>>>()
+    }
+}