From c8280ae8712f1d4f185505bd9b10f5c8f3de316a Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sun, 12 Apr 2026 03:02:32 -0400
Subject: [PATCH] parser: add composite sort expressions

Adds parsing for weighted sort expressions like:
  sort:degree*0.5+isolation*0.3+recency(organize)*0.2

This fixes organize agent which uses composite scoring.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>
---
 src/hippocampus/query/parser.rs | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/hippocampus/query/parser.rs b/src/hippocampus/query/parser.rs
index e80dd1c..ccc3ae5 100644
--- a/src/hippocampus/query/parser.rs
+++ b/src/hippocampus/query/parser.rs
@@ -28,7 +28,7 @@ use std::collections::BTreeMap;
 
 // Re-export engine types used by Query
 pub use super::engine::{
-    Stage, Filter, Transform, Generator, SortField,
+    Stage, Filter, Transform, Generator, SortField, ScoreField,
     Algorithm, AlgoStage, Cmp,
 };
 
@@ -92,7 +92,7 @@ peg::parser! {
             / "connectivity" { Stage::Transform(Transform::Connectivity) }
             / "dominating-set" { Stage::Transform(Transform::DominatingSet) }
             // Pipeline syntax (colon-separated)
-            / "sort:" f:field() { Stage::Transform(Transform::Sort(make_sort_field(&f, false))) }
+            / "sort:" c:composite_sort() { Stage::Transform(Transform::Sort(c)) }
             / "limit:" n:integer() { Stage::Transform(Transform::Limit(n)) }
             / "select:" f:field_list_colon() { Stage::Transform(Transform::Select(f)) }
             / "type:" t:ident() { make_type_filter(&t) }
@@ -111,6 +111,27 @@ peg::parser! {
             / "desc" { false }
             / { false }  // default: descending
 
+        // Composite sort: degree*0.5+isolation*0.3+recency(organize)*0.2
+        // Falls back to simple field if no weighted terms found.
+        rule composite_sort() -> SortField
+            = t:score_term() ts:("+" t:score_term() { t })+ {
+                let mut terms = vec![t];
+                terms.extend(ts);
+                SortField::Composite(terms)
+            }
+            / f:field() { make_sort_field(&f, false) }
+
+        rule score_term() -> (ScoreField, f64)
+            = "recency(" a:ident() ")" "*" w:number() { (ScoreField::Recency(a), w) }
+            / f:score_field_name() "*" w:number() { (f, w) }
+
+        rule score_field_name() -> ScoreField
+            = "isolation" { ScoreField::Isolation }
+            / "degree" { ScoreField::Degree }
+            / "weight" { ScoreField::Weight }
+            / "content-len" { ScoreField::ContentLen }
+            / "priority" { ScoreField::Priority }
+
         rule field_list_colon() -> Vec<String>
             = f:field() fs:("," f:field() { f })* {
                 let mut v = vec![f];