Improve the clean command

build.sh

@@ -2,7 +2,20 @@
 
 set -euo pipefail
 
-RUST_ALL_TARGETS="dashboard ifc memorycache geo-types fluent-ergonomics cyberpunk-splash screenplay emseries coordinates flow sgf changeset"
+RUST_ALL_TARGETS=(
+    "dashboard"
+    "ifc"
+    "memorycache"
+    "geo-types"
+    "fluent-ergonomics"
+    "cyberpunk-splash"
+    "screenplay"
+    "emseries"
+    "coordinates"
+    "flow"
+    "sgf"
+    "changeset"
+)
 
 build_rust_targets() {
     local CMD=$1
@@ -23,8 +36,13 @@ if [ -z "${CMD-}" ]; then
     CMD="release"
 fi
 
+if [ "${CMD}" == "clean" ]; then
+    cargo clean
+    exit 0
+fi
+
 if [ "${TARGET}" == "all" ]; then
-    build_rust_targets $CMD $RUST_ALL_TARGETS
+    build_rust_targets $CMD ${RUST_ALL_TARGETS[*]}
 else
     build_rust_targets $CMD $TARGET
 fi