iface: add contract state accessing methods to IfaceWrapper

src/interface/iface.rs

@@ -30,7 +30,8 @@ use amplify::{ByteArray, Bytes32};
 use baid64::{Baid64ParseError, DisplayBaid64, FromBaid64Str};
 use chrono::{DateTime, TimeZone, Utc};
 use commit_verify::{CommitId, CommitmentId, DigestExt, Sha256};
-use rgb::{Identity, Occurrences};
+use rgb::vm::WitnessOrd;
+use rgb::{ContractId, Identity, Occurrences, SchemaId, XWitnessId};
 use strict_encoding::{
     FieldName, StrictDecode, StrictDeserialize, StrictDumb, StrictEncode, StrictSerialize,
     StrictType, TypeName, VariantName,
@@ -341,6 +342,10 @@ pub trait IfaceClass: Clone + Default {
     fn stl(&self) -> TypeLib;
     fn iface(&self) -> Iface;
     fn iface_id(&self) -> IfaceId;
+
+    fn contract_id(&self) -> ContractId;
+    fn schema_id(&self) -> SchemaId;
+    fn witness_info(&self, witness_id: XWitnessId) -> Option<WitnessOrd>;
 }
 
 /// The instances implementing this trait are used as wrappers around