Add values_at

automerge/src/automerge.rs

@@ -12,7 +12,7 @@ use crate::types::{
     ActorId, AssignPatch, ChangeHash, Clock, ElemId, Export, Exportable, Key, ObjId, Op, OpId,
     OpType, Patch, ScalarValue, Value,
 };
-use crate::{legacy, query, types, ObjType, RangeAt};
+use crate::{legacy, query, types, ObjType, RangeAt, ValuesAt};
 use crate::{AutomergeError, Change, Prop};
 use crate::{KeysAt, Values};
 use serde::Serialize;
@@ -397,6 +397,17 @@ impl Automerge {
         }
     }
 
+    /// Historical version of [`values`](Self::values).
+    pub fn values_at<O: AsRef<ExId>>(&self, obj: O, heads: &[ChangeHash]) -> ValuesAt {
+        if let Ok(obj) = self.exid_to_obj(obj.as_ref()) {
+            let clock = self.clock_at(heads);
+            let iter_range = self.ops.range_at(obj, .., clock);
+            ValuesAt::new(self, iter_range)
+        } else {
+            ValuesAt::new(self, None)
+        }
+    }
+
     /// Get the length of the given object.
     pub fn length<O: AsRef<ExId>>(&self, obj: O) -> usize {
         if let Ok(inner_obj) = self.exid_to_obj(obj.as_ref()) {

automerge/src/lib.rs

@@ -47,6 +47,7 @@ pub mod transaction;
 mod types;
 mod value;
 mod values;
+mod values_at;
 #[cfg(feature = "optree-visualisation")]
 mod visualisation;
 
@@ -66,5 +67,6 @@ pub use range_at::RangeAt;
 pub use types::{ActorId, AssignPatch, ChangeHash, ObjType, OpType, Patch, Prop};
 pub use value::{ScalarValue, Value};
 pub use values::Values;
+pub use values_at::ValuesAt;
 
 pub const ROOT: ObjId = ObjId::Root;

automerge/src/values_at.rs

@@ -0,0 +1,26 @@
+use crate::{exid::ExId, Value};
+use std::ops::RangeFull;
+
+use crate::{query, Automerge};
+
+pub struct ValuesAt<'a, 'k> {
+    range: Option<query::RangeAt<'k, RangeFull>>,
+    doc: &'a Automerge,
+}
+
+impl<'a, 'k> ValuesAt<'a, 'k> {
+    pub(crate) fn new(doc: &'a Automerge, range: Option<query::RangeAt<'k, RangeFull>>) -> Self {
+        Self { range, doc }
+    }
+}
+
+impl<'a, 'k> Iterator for ValuesAt<'a, 'k> {
+    type Item = (String, Value, ExId);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.range
+            .as_mut()?
+            .next()
+            .map(|(key, value, id)| (self.doc.to_string(key), value, self.doc.id_to_exid(id)))
+    }
+}