make parse_lookup_arg behave in a more correct way

.circleci/config.yml

@@ -0,0 +1,9 @@
+version: '2.1'
+orbs:
+  rust: circleci/rust@1.6.1
+workflows:
+  production:
+    jobs:
+      - rust/lint-test-build:
+          release: true
+          version: 1.75.0

.pre-commit-config.yaml

@@ -0,0 +1,16 @@
+repos:
+-   repo: https://github.com/doublify/pre-commit-rust
+    rev: v1.0
+    hooks:
+    -   id: fmt
+    -   id: cargo-check
+        entry: env RUSTFLAGS="-D warnings" cargo check
+        args: ['--all']
+    -   id: clippy
+    -   id: cargo-check
+        name: cargo-check --features image
+        entry: env RUSTFLAGS="-D warnings" cargo check
+        args: ['--all', '--features', 'image']
+    -   id: clippy
+        name: clippy --features image
+        args: ['--features', 'image']