Add helper functions for FFI. Many of these will go away as we expose the entity builder

src/conn.rs

@@ -81,6 +81,7 @@ use mentat_tolstoy::Syncer;
 use uuid::Uuid;
 
 use entity_builder::{
+    BuildTerms,
     InProgressBuilder,
 };
 
@@ -578,6 +579,10 @@ impl Store {
     pub fn unregister_observer(&mut self, key: &String) {
         self.conn.unregister_observer(key);
     }
+
+    pub fn add_value_for_attribute<T>(&mut self, entid: T, attribute: NamespacedKeyword, value: TypedValue) -> Result<()> where T: Into<KnownEntid> {
+        self.conn.add_value_for_attribute(&mut self.sqlite, entid, attribute, value)
+    }
 }
 
 impl Queryable for Store {
@@ -865,6 +870,18 @@ impl Conn {
     pub fn unregister_observer(&mut self, key: &String) {
         self.tx_observer_service.lock().unwrap().deregister(key);
     }
+
+    // TODO: expose the entity builder over FFI and remove the need for this function entirely
+    // It's really only here in order to keep the FFI layer as thin as possible.
+    // Once the entity builder is exposed, we can perform all of these functions over FFI from the client.
+    pub fn add_value_for_attribute<T>(&mut self, sqlite: &mut rusqlite::Connection, entid: T, attribute: NamespacedKeyword, value: TypedValue) -> Result<()> where T: Into<KnownEntid> {
+        let in_progress = self.begin_transaction(sqlite)?;
+        let mut builder = in_progress.builder().describe(entid.into());
+        builder.add_kw(&attribute, value)?;
+        builder.commit()
+               .map_err(|e| e.into())
+               .and(Ok(()))
+    }
 }
 
 #[cfg(test)]