Fix optional field in persisted tables

Cargo.toml

@@ -3,7 +3,7 @@ members = ["codegen", "examples", "performance_measurement", "performance_measur
 
 [package]
 name = "worktable"
-version = "0.8.18"
+version = "0.8.19"
 edition = "2024"
 authors = ["Handy-caT"]
 license = "MIT"
@@ -16,7 +16,7 @@ perf_measurements = ["dep:performance_measurement", "dep:performance_measurement
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-worktable_codegen = { path = "codegen", version = "=0.8.18" }
+worktable_codegen = { path = "codegen", version = "=0.8.19" }
 
 eyre = "0.6.12"
 derive_more = { version = "2.0.1", features = ["from", "error", "display", "into"] }
@@ -27,9 +27,9 @@ lockfree = { version = "0.5.1" }
 fastrand = "2.3.0"
 futures = "0.3.30"
 uuid = { version = "1.10.0", features = ["v4", "v7"] }
-data_bucket = "=0.3.9"
+data_bucket = "=0.3.10"
 # data_bucket = { git = "https://github.com/pathscale/DataBucket", branch = "page_cdc_correction", version = "0.2.7" }
-# data_bucket = { path = "../DataBucket", version = "0.3.8" }
+# data_bucket = { path = "../DataBucket", version = "0.3.9" }
 performance_measurement_codegen = { path = "performance_measurement/codegen", version = "0.1.0", optional = true }
 performance_measurement = { path = "performance_measurement", version = "0.1.0", optional = true }
 indexset = { version = "=0.14.0", features = ["concurrent", "cdc", "multimap"] }

codegen/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "worktable_codegen"
-version = "0.8.18"
+version = "0.8.19"
 edition = "2024"
 license = "MIT"
 description = "WorkTable codegeneration crate"

codegen/src/persist_index/generator.rs

@@ -58,23 +58,31 @@ impl Generator {
                     .clone()
                     .expect("index fields should always be named fields"),
             );
-            let index_type = field.ty.to_token_stream().to_string();
-            let mut split = index_type.split("<");
-            // skip `IndexMap` ident.
-            split.next();
-            let substr = split
-                .next()
-                .expect("index type should always contain key generic")
-                .to_string();
-            types.push(
-                substr
-                    .split(",")
-                    .next()
-                    .expect("index type should always contain key and value generics")
-                    .to_string()
-                    .parse()
-                    .expect("should be valid because parsed from declaration"),
-            );
+
+            let syn::Type::Path(type_path) = &field.ty else {
+                unreachable!()
+            };
+
+            let last_segment = type_path
+                .path
+                .segments
+                .last()
+                .expect("Index type should have at least one segment");
+
+            let syn::PathArguments::AngleBracketed(arguments) = &last_segment.arguments else {
+                unreachable!("IndexMap always have angle brackets arguments which are generic")
+            };
+
+            let first_arg = arguments
+                .args
+                .first()
+                .expect("Index type should have at least one type argument");
+
+            let syn::GenericArgument::Type(ty) = first_arg else {
+                unreachable!("Index type should have at least one type argument")
+            };
+
+            types.push(ty.to_token_stream());
         }
         let map = fields.into_iter().zip(types).collect::<HashMap<_, _>>();