It works perfectly with some Rhai

milli/Cargo.toml

@@ -83,7 +83,7 @@ rand = "0.8.5"
 tracing = "0.1.40"
 ureq = { version = "2.10.0", features = ["json"] }
 url = "2.5.2"
-piccolo = "0.3.1"
+rhai = { version = "1.18.0", features = ["serde", "no_module", "no_custom_syntax"] }
 
 [dev-dependencies]
 mimalloc = { version = "0.1.43", default-features = false }

milli/src/update/index_documents/mod.rs

@@ -16,6 +16,7 @@ use grenad::{Merger, MergerBuilder};
 use heed::types::Str;
 use heed::Database;
 use rand::SeedableRng;
+use rhai::{Engine, Scope};
 use roaring::RoaringBitmap;
 use serde::{Deserialize, Serialize};
 use slice_group_by::GroupBy;
@@ -32,7 +33,7 @@ pub use self::helpers::{
 };
 use self::helpers::{grenad_obkv_into_chunks, GrenadParameters};
 pub use self::transform::{Transform, TransformOutput};
-use crate::documents::{obkv_to_object, DocumentsBatchReader};
+use crate::documents::{obkv_to_object, DocumentsBatchBuilder, DocumentsBatchReader};
 use crate::error::{Error, InternalError, UserError};
 use crate::thread_pool_no_abort::ThreadPoolNoAbortBuilder;
 pub use crate::update::index_documents::helpers::CursorClonableMmap;
@@ -40,7 +41,7 @@ use crate::update::{
     IndexerConfig, UpdateIndexingStep, WordPrefixDocids, WordPrefixIntegerDocids, WordsPrefixesFst,
 };
 use crate::vector::EmbeddingConfigs;
-use crate::{fields_ids_map, CboRoaringBitmapCodec, Index, Result};
+use crate::{CboRoaringBitmapCodec, FieldsIdsMap, Index, Object, Result};
 
 static MERGED_DATABASE_COUNT: usize = 7;
 static PREFIX_DATABASE_COUNT: usize = 4;
@@ -174,7 +175,7 @@ where
 
     #[tracing::instrument(level = "trace", skip_all, target = "indexing::documents")]
     pub fn edit_documents(
-        mut self,
+        self,
         documents: &RoaringBitmap,
         code: &str,
     ) -> Result<(Self, StdResult<u64, UserError>)> {
@@ -183,49 +184,75 @@ where
             return Ok((self, Ok(0)));
         }
 
-        let mut lua = piccolo::Lua::core();
-        let executor = lua.enter(|ctx| ctx.stash(piccolo::Executor::new(ctx)));
-        let fields_ids_map = self.index.fields_ids_map(self.wtxn)?;
-
-        for docid in documents {
-            let document = match self.index.documents.get(self.wtxn, &docid)? {
-                Some(document) => document,
-                None => panic!("a document should always exists"),
-            };
-
-            lua.try_enter(|ctx| {
-                let closure = match piccolo::Closure::load(
-                    ctx,
-                    None,
-                    ("return ".to_string() + code).as_bytes(),
-                ) {
-                    Ok(closure) => closure,
-                    Err(_) => piccolo::Closure::load(ctx, None, code.as_bytes())?,
-                };
-                let function = piccolo::Function::Closure(closure);
-
-                let table = piccolo::Table::new(&ctx);
-                table.set(ctx, "internal-id", docid)?;
-                table.set(ctx, "title", "hello")?;
-                table.set(ctx, "description", "world")?;
-                dbg!(&table);
-                ctx.set_global("doc", table)?;
-
-                ctx.fetch(&executor).restart(ctx, function, ());
-                Ok(())
-            })
-            .unwrap();
-
-            lua.execute::<()>(&executor).unwrap();
-            lua.try_enter(|ctx| {
-                let value = ctx.get_global("doc");
-                dbg!(value);
-                Ok(())
-            })
-            .unwrap();
+        /// Transform every field of a raw obkv store into a JSON Object.
+        pub fn all_obkv_to_rhaimap(
+            obkv: obkv::KvReaderU16,
+            fields_ids_map: &FieldsIdsMap,
+        ) -> Result<rhai::Map> {
+            let all_keys = obkv.iter().map(|(k, _v)| k).collect::<Vec<_>>();
+            all_keys
+                .iter()
+                .copied()
+                .flat_map(|id| obkv.get(id).map(|value| (id, value)))
+                .map(|(id, value)| {
+                    let name = fields_ids_map.name(id).ok_or(
+                        crate::error::FieldIdMapMissingEntry::FieldId {
+                            field_id: id,
+                            process: "allobkv_to_rhaimap",
+                        },
+                    )?;
+                    let value = serde_json::from_slice(value)
+                        .map_err(crate::error::InternalError::SerdeJson)?;
+                    Ok((name.into(), value))
+                })
+                .collect()
         }
 
-        Ok((self, Ok(documents.len())))
+        fn rhaimap_to_object(map: rhai::Map) -> Object {
+            let mut output = Object::new();
+            for (key, value) in map {
+                let value = serde_json::to_value(&value).unwrap();
+                output.insert(key.into(), value);
+            }
+            output
+        }
+
+        let engine = Engine::new();
+        let ast = engine.compile(code).unwrap();
+        let fields_ids_map = self.index.fields_ids_map(self.wtxn)?;
+        let primary_key = self.index.primary_key(self.wtxn)?.unwrap();
+        let primary_key_id = fields_ids_map.id(primary_key).unwrap();
+        let mut documents_batch_builder = tempfile::tempfile().map(DocumentsBatchBuilder::new)?;
+
+        for docid in documents {
+            let (document, document_id) = match self.index.documents.get(self.wtxn, &docid)? {
+                Some(obkv) => {
+                    let document_id_bytes = obkv.get(primary_key_id).unwrap();
+                    let document_id: serde_json::Value =
+                        serde_json::from_slice(document_id_bytes).unwrap();
+                    let document = all_obkv_to_rhaimap(obkv, &fields_ids_map)?;
+                    (document, document_id)
+                }
+                None => panic!("documents must exist"),
+            };
+
+            let mut scope = Scope::new();
+            scope.push("doc", document);
+
+            let new_document = engine.eval_ast_with_scope::<rhai::Map>(&mut scope, &ast).unwrap();
+            let new_document = rhaimap_to_object(new_document);
+
+            assert_eq!(
+                document_id, new_document[primary_key],
+                "you cannot change the document id when editing documents"
+            );
+            documents_batch_builder.append_json_object(&new_document)?;
+        }
+
+        let file = documents_batch_builder.into_inner()?;
+        let reader = DocumentsBatchReader::from_reader(file)?;
+
+        self.add_documents(reader)
     }
 
     pub fn with_embedders(mut self, embedders: EmbeddingConfigs) -> Self {