Rewrite JSON parsing code in Perl for portability

src/_cmake

@@ -141,21 +141,14 @@ _cmake_generator_options() {
 # --------------
 (( $+functions[_cmake_presets] )) ||
 _cmake_presets() {
-
-  local parse_presets; parse_presets='
-import json    
-import os    
-try:    
-    with open("CMakePresets.json") as preset_file:    
-        print(os.linesep.join([ x["name"] + ":" + x.get("description", "") for x in json.load(preset_file)["configurePresets"]]))
-except:    
-    pass    
-
-'
-
   # TODO: Problems with quotes need eval
   # would need a way to exec the array
-  local list_presets; list_presets=(${(f)"$(eval python <<< $parse_presets)"})
+  local -a list_presets;
+
+  if [[ -e CMakePresets.json ]]; then
+    # some old projects uses BOM in json file. strip UTF-8 BOM and then parse JSON
+    list_presets=("${(@f)$(sed '1s/^\xEF\xBB\xBF//' < CMakePresets.json | perl -0777 -MJSON::PP -nE 'do{$k=$_;($e=$k)=~s/:/\\:/g; printf "$_->{name}:$_->{description}\n"} for @{decode_json($_)->{configurePresets}}' 2>/dev/null)}")
+  fi
 
   _describe 'presets' list_presets
 }