Fix bench script; Update highlight queries

scripts/bench.fish

@@ -11,7 +11,7 @@ hyperfine \
       --shell none \
       --parameter-list data_path examples/assets/seaCreatures.json,examples/assets/jq_data.json,dielectron.json \
       --warmup 3 \
-      "dust -c '(length (from_json input))' -p {data_path}" \
+      "dust -c 'length(from_json(input))' -p {data_path}" \
       "jq 'length' {data_path}" \
       "node --eval \"require('node:fs').readFile('{data_path}', (err, data)=>{console.log(JSON.parse(data).length)})\"" \
       "nu -c 'open {data_path} | length'"

tree-sitter-dust/highlights.scm

@@ -39,7 +39,6 @@
       "else"
       "false"
       "float"
-      "fn"
       "for"
       "if"
       "in"
@@ -50,6 +49,8 @@
       "str"
       "true"
       "while"
+      "->"
+      "=>"
 ] @keyword
 
 (built_in_function) @function.builtin