sorters

.idea/vcs.xml

@@ -2,7 +2,6 @@
 <project version="4">
   <component name="VcsDirectoryMappings">
     <mapping directory="$PROJECT_DIR$" vcs="Git" />
-    <mapping directory="$PROJECT_DIR$/cozorocks/jemalloc" vcs="Git" />
     <mapping directory="$PROJECT_DIR$/cozorocks/rocksdb" vcs="Git" />
   </component>
 </project>

cozopy/cozo.py

@@ -14,7 +14,7 @@ class CozoDb:
     def tx(self, payload):
         return json.loads(self.inner.transact_triples(json.dumps({'tx': payload}, ensure_ascii=False)))
 
-    def run(self, q, out=None, limit=None, offset=None):
+    def run(self, q, out=None, limit=None, offset=None, sort=None):
         payload = {'q': q}
         if out is not None:
             payload['out'] = out
@@ -22,9 +22,20 @@ class CozoDb:
             payload['limit'] = limit
         if offset is not None:
             payload['offset'] = offset
+        if sort is not None:
+            payload['sort'] = [convert_sort_arg(arg) for arg in sort]
         return json.loads(self.inner.run_query(json.dumps(payload, ensure_ascii=False)))
 
 
+def convert_sort_arg(arg):
+    if arg.startswith('+'):
+        return {arg[1:]: 'asc'}
+    elif arg.startswith('-'):
+        return {arg[1:]: 'desc'}
+    else:
+        return {arg: 'asc'}
+
+
 class Typing(str, Enum):
     ref = 'ref'
     component = 'component'

src/parse/query.rs

@@ -22,11 +22,32 @@ use crate::utils::swap_result_option;
 
 pub(crate) type OutSpec = (Vec<(usize, Option<PullSpecs>)>, Option<Vec<String>>);
 
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub(crate) enum SortDir {
+    Asc,
+    Dsc,
+}
+
+impl TryFrom<&'_ JsonValue> for SortDir {
+    type Error = anyhow::Error;
+
+    fn try_from(value: &'_ JsonValue) -> std::result::Result<Self, Self::Error> {
+        match value {
+            JsonValue::String(s) => {
+                todo!()
+            }
+            _ => bail!("unexpected value {} for sort direction specification", value)
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub(crate) struct QueryOutOptions {
     pub(crate) out_spec: Option<OutSpec>,
     pub(crate) vld: Validity,
     pub(crate) limit: Option<usize>,
     pub(crate) offset: Option<usize>,
+    pub(crate) sorters: Vec<(Symbol, SortDir)>,
 }
 
 impl QueryOutOptions {
@@ -82,6 +103,19 @@ impl SessionTx {
                 .map(|v| v as usize)
                 .ok_or_else(|| anyhow!("'offset' must be a positive number"))
         }))?;
+        let sorters = payload.get("sort")
+            .unwrap_or_else(|| &json!([]))
+            .as_array()
+            .ok_or_else(|| anyhow!("'sort' is expected to be an array"))?
+            .iter()
+            .map(|sorter| -> Result<(Symbol, SortDir)> {
+                let sorter = sorter.as_object()
+                    .ok_or_else(|| anyhow!("'sort' must be an array of objects"))?;
+                ensure!(sorter.len() == 1, "'sort' spec must be an object of a single pair");
+                let (k, v) = sorter.iter().next().unwrap();
+
+                todo!()
+            }).try_collect()?;
         Ok((
             input_prog,
             QueryOutOptions {
@@ -89,6 +123,7 @@ impl SessionTx {
                 vld,
                 limit,
                 offset,
+                sorters
             },
         ))
     }