Zig queries: highlight, fold and indent

* fold for if/while/for
 * highlight "_" for ignore variable
 * highlight "c" for PtrTypeStart
 * highlight "?" for optional type
 * remove duplicate query node in indent

queries/zig/folds.scm

@@ -6,4 +6,11 @@
   (AsmExpr)
   (ErrorSetDecl)
   (LINESTRING)
+  (
+    [
+      (IfPrefix)
+      (WhilePrefix)
+      (ForPrefix)
+    ]
+  )
 ] @fold

queries/zig/highlights.scm

@@ -23,7 +23,7 @@ parameter: (IDENTIFIER) @parameter
     field_access: (IDENTIFIER)
     parameter: (IDENTIFIER)
   ] @type
-  (#match? @type "^[A-Z]([a-z0-9]+[A-Za-z0-9]*)*$")
+  (#match? @type "^[A-Z]([a-z]+[A-Za-z0-9]*)*$")
 )
 ;; assume camelCase is a function
 (
@@ -51,6 +51,13 @@ parameter: (IDENTIFIER) @parameter
 
 exception: "!" @exception
 
+(
+  (IDENTIFIER) @variable.builtin
+  (#eq? @variable.builtin "_")
+)
+
+(PtrTypeStart "c" @variable.builtin)
+
 (
   (ContainerDeclType
     [
@@ -58,9 +65,7 @@ exception: "!" @exception
       "enum"
     ]
   )
-  (ContainerMembers
-    (ContainerField (IDENTIFIER) @constant)
-  )
+  (ContainerField (IDENTIFIER) @constant)
 )
 
 field_constant: (IDENTIFIER) @constant
@@ -199,6 +204,7 @@ field_constant: (IDENTIFIER) @constant
   ".?"
   ".*"
   "="
+  "?"
 ] @operator
 
 [

queries/zig/indents.scm

@@ -3,7 +3,6 @@
   (ContainerDecl)
   (SwitchExpr)
   (InitList)
-  (ContainerDecl)
 ] @indent
 
 [